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Bad Specs

We welcome readers to submit their own stories of baffling project insulation requirements and weird specifications. Send your stories or requests to be interviewed to editor@insulation.org.

Greetings, fellow insulation enthusiasts! As we all know, the world of construction specifications can be a perplexing and often humorous place. From the sublime to the ridiculous, we've all encountered those specifications that leave us scratching our heads, wondering if the specifier truly understands what they’re asking for.

To share these experiences—and hopefully prevent future bouts of head-scratching—I’m thrilled to introduce a new column in our magazine: “Bad Specs.”

“Bad Specs” will explore the fascinating world of—yes, you guessed it—poorly written specifications. Each month, an Insulation Outlook reader will share their experiences, diving into the depths of confusion and uncovering the most perplexing, puzzling, and downright hilarious requests that have graced our desks (or, more accurately, our inboxes) over the years. Think of it as a cautionary tale, a chance to learn from the missteps of others, and a reminder of the importance of clear and concise communication in our industry.

For this inaugural column, Insulation Outlook’s Julie McLaughlin, invited me, Scott Sinclair (also from Johns Manville), and Doug Fast of Owens Corning to discuss the most common types of baffling requests we receive, so she could determine how to shape this column. We all had some good ones.

Doug Fast offered a great analogy for a common problem in specs: a lack of detail. He said, “It would be like going into a restaurant and ordering your meal as ‘beef’… You may get a hamburger or a steak, and both technically fit your request. With specifications, you need to define the details of the product you actually want.”

We see the opposite problem, too. Some people order a steak but then insist that it be cooked on a specific grill, using a specific type of charcoal, cooked precisely to 165°F, and served bloody. Only some of those requests work together.

During our discussion, we found that specification errors tend to fall into certain categories. Here’s a handy list to help future authors frame their experiences in a way that can help others:

  • Cut-and-Paste Minefields
    Do you know how old that language is? Was it created in this decade? Before you were born?
  • Accidental Technical Errors and Transposed Numbers
    Simple mistakes, big problems!
  • Conflicting Standards and Requests
    “Waiter, I’d like one bloody, well-done steak, please!”
  • Missing Links
    References to standards and materials that no longer exist.
  • Prescriptive versus Performance Specifications
    Example: Nominal density versus actual density: “I need 8 pounds, but this is actually 6½.” “Yep.” “Why is XXX called 6½ pounds in the residential market but 8 pounds in the industrial market?”
  • Specifying a Characteristic versus Specifying System Performance
    Example: Insisting on a certain density rather than requiring the insulation to meet a specific thermal performance standard.
  • Getting the Insulation Right but Adding Bad Installation Requests
    Example: Requiring the contractor to secure insulation with staples or screws on a below-ambient system. Whoops! There goes your system.
  • System Performance Metrics Applied to Products
    Example: What is the Sound Transmission Class (STC) of a fiber glass board? An STC value is a measure of the system performance of a wall, floor, or ceiling partition.

We welcome readers to submit their own stories of baffling project insulation requirements and weird specifications.

Sometimes, the requests we receive are really outdated. The question I got recently was in a league of its own. Occasionally, people specify a certain brand of insulation—only to learn that “Brand X” hasn’t been manufactured since the rotary phone was king. This was worse. Someone recently asked about a mastic product produced 100 years ago and installed on a hydro dam in the 1930s, maybe as part of FDR's New Deal. They thought it had be applied as part of a "Hoosier" expansion joint. They asked if there was a friction or cohesive test for it. I asked for more details, and in response, I received a tele-ex! For those of you asking what that is, it is a technology that predates the fax machine! And it get better. This tele-ex mentions previous information being sent via TELEGRAM. (The image below is what they sent me.) If you are working on a project that was built by telegrammed instructions, maybe stop for a moment and ask yourself if this is the best you can do. Is this the best system for the equipment or company? Maybe it is time to investment in new insulation. Just a guess, but I feel like we can make a better system for you now.

This is all the information they had in their records to go on. I feel for them. Imagine taking on a project and this is all the information that they can provide you. It mentions a asphalt and asbestos mixture so clearly that is no longer being made!

Scott Sinclair, saying that Johns Manville has also gotten calls for replacement parts made “during the war.” We haven’t manufactured those since the 1940s!

Everyone in the industry has encountered boilerplate language requesting materials made with asbestos—despite its ban in the 1970s. That means no one at that company has updated those specs in nearly three generations! I know insulation is just a small part of the job, but come on!

In future “Bad Specs” columns, we’ll delve into other fascinating topics, such as the perils of “cut-and-paste” specifications, the amusing consequences of transposed terms, and the occasional appearance of mythical insulation materials that defy the laws of physics.

So buckle up, my friends. It’s going to be a wild ride. And remember: A little laughter goes a long way in this industry. After all, what’s life without a good chuckle at the expense of a particularly perplexing specification?

I hope you find this column engaging and informative!

Disclaimer: This column is intended for entertainment purposes only. Any resemblance to actual persons, living or dead, is purely coincidental (and probably a little exaggerated). Consult the experts before trying to resurrect ancient insulation materials.

NIA Sites > Insulation Outlook Magazine > Global

A Blueprint for a Clean and Competitive Industrial Sector

The U.S. Department of Energy (DOE) and the White House Office of Science and Technology Policy, with input from departments and agencies across the federal government, have released The National Blueprint for a Clean & Competitive Industrial Sector (Blueprint). Building on ongoing industrial investments across federal agencies, the Blueprint outlines five strategies within a private-sector-led and government-enabled framework to fuel continued growth of American manufacturing.

This Blueprint lays out a pathway to achieve a low-carbon U.S. industrial sector that is less polluting; more economically competitive; resilient to changing global market conditions; and a contributor to good jobs and revitalization of industrial communities, public health, energy and environmental justice1, and national security.

The industrial sector is diverse and includes manufacturing and non-manufacturing subsectors (agriculture, mining, and construction), which together contribute approximately 38% of total greenhouse gas (GHG) emissions.2 This Blueprint focuses on manufacturing because it is the largest consumer of energy and source of emissions within the broader industrial sector.

The objective of the Blueprint is to elicit rapid near-term GHG emissions reductions and expanded economic competitiveness while advancing transformative solutions for the long term. Through collaborations between the U.S. government and owners and operators of manufacturing plants, labor unions, civil society organizations in industrial communities, environmental groups, technology providers, equipment manufacturers, engineering firms, and project developers, the vision of this Blueprint can become a reality. It also aims to promote communication with communities and Tribal nations to ensure all impacted stakeholders have a voice in the transition to co-produce and deploy solutions that generate benefits for all.

 

The Blueprint establishes five strategies to guide near-term federal government coordination.

Accelerate deployment of commercially available, cost-effective lower carbon solutions in the near term. Commercially available alternatives to high-emitting industrial processes that could achieve a 10% to 15% reduction in GHG emissions by 2030 already exist.3 The Pathways to Commercial Liftoff Report4 identifies that approximately another 25% emissions reductions are possible by 2030 by actions outside of industrial facilities through the progressive reduction of GHG emissions from the U.S. power and transportation sectors. Federal government coordination is necessary to accelerate deployment of these technologies, which often face barriers associated with industry inertia, the lack of familiarity with new materials or manufacturing techniques, lack of finance for capital-intensive upgrades, and/or risk avoidance.

Demonstrate emerging solutions at commercial scale to de-risk deployment. Deep emissions reductions in many subsectors will require new large-scale changes to methods of production. The private sector is uniquely positioned to envision and build these commercial first-of-a-kind projects. Although these projects will require significant investment, they will produce a critical knowledge base for the domestic industrial sector and the clean energy research and development community, not only serving as a foundation for establishing the necessary enabling supply chain, permitting, and innovation to expand these technologies to commercial scale, but also allowing the supply chain to remain competitive with overseas players.

Increase data use to drive emissions reductions and efficiency gains that can significantly improve performance and track progress. In recent years, emissions intensity measurement and reporting systems have grown more robust and standardized, enabling manufacturers to accurately track emissions reductions and gain access to growing low-carbon markets. Meanwhile, digital technologies, including emerging forms of sensing, and computational tools are enabling new frontiers in the ways industries manage operations that could lead to efficiency gains that reduce GHG emissions. Hardware tools such as ubiquitous sensors and cyber-physical systems can capture additional data necessary to apply software tools, such as distributed computing, artificial intelligence/machine learning, the Internet of Things, digital twins, and continuous learning. These approaches represent a shift in controls for industrial facilities that was not possible a decade ago.

Innovate and advance research to develop transformative processes and products for deep GHG emissions reductions. Bringing low-emissions industrial processes and materials innovations to market quickly and efficiently means fast-tracking the stages of innovation to maximize the impact of technology investments. The International Energy Agency estimates 55% of emissions reductions technologies necessary to meet net zero are not yet in commercial stage. An example of this is cement, where technologically mature approaches such as use of supplementary cementitious materials or calcined clay can reduce emissions by 30% to 40%, but further reductions will require new processes or products. At each stage of innovation, the government can play an important role. The first stage involves solution discovery of low-emission processes and material innovations, and partnerships with government agencies and research institutions play a crucial role in this phase. Next, the product development phase to develop a minimum viable product (MVP) can leverage agile methodologies, continuous iteration, and collaboration with potential customers. The third phase is the pilot demonstration phase to test the MVP in real-world industrial settings. Finally, in the go-to-market and scale stage, the solution transitions from pilot to full-scale deployment, and can leverage investments through incentives like tax credits, grants, and strategic partnerships.

Integrate across the product life cycle to reduce embodied GHG emissions in industrial products and minimize waste. Establishing standards and evaluation methods to monitor emissions across supply chains, from raw material extraction to end-of-life disposal, can create important efficiencies. Many opportunities to reduce embodied emissions are driven by mitigation opportunities outside the industrial facility fence line. Manufacturers must deepen their understanding of both the upstream and downstream effects associated with all input and output materials. This knowledge is crucial for maximizing circularity within their operations. By doing so, they can extend the lifespan of existing materials and contribute to a more sustainable manufacturing process. Additionally, co-locating with other manufacturers can create opportunities for mutual benefits. It will be important for manufacturers to inform any co-location decisions to ensure partnerships enhance resource efficiency and promote a circular economy. Scaling these efforts will require the advancement of standards and evaluation methods to share data on carbon production and reductions across supply chains.

The Blueprint also details a set of levers, that is, programs available to governments to support this transition: expanding supply-side investments; creating demand-pull; implementing codes, standards, and reporting requirements; ensuring locally defined benefits for workers and communities; developing a common infrastructure; increasing data transparency; and expanding international cooperation. Implementing these levers to achieve the strategies outlined in the Blueprint will translate to substantial improvements in public health, accelerated innovation to support U.S. international competitiveness, reduced GHG emissions, mitigated fiscal and climate risk, expansion of high-paying jobs, more efficient stewardship of U.S. natural resources, renewed investments in industrial communities, and both near- and long-term financial stability. The implementation also aims to strengthen U.S. diplomatic standing and influence international policy to benefit both domestic and global environmental outcomes.

 

A Call to Action

The industrial sector has historically been referred to as “hard-to-abate.” Although the challenges are real, that understanding is changing. The market for low-carbon materials such as green steel and low-carbon cement is growing. The technologies that producers have available to them to initiate these emissions reductions are being proven at commercial scale. There are innovative deep decarbonization solutions in research and development, attracting new talent to solve these challenges. Whereas the transition will take time, the next few years are vital for building the momentum needed to propel the economy forward over the coming decades. The Blueprint lays out federal actions that would support decarbonization of U.S. industry in line with the U.S. long-term strategy, while ensuring the greatest realization of co-benefits are achieved to strengthen economic prosperity, health, employment, and security across the country. Successful implementation of the programs already in progress, increased interagency cooperation, and a detailed plan with continued private sector engagement are the next steps for putting this Blueprint into action.

 

References

 

To access the DOE’s National Blueprint for a Clean &Competitive Industrial Sector report, visit www.energy.gov/mesc/reports. Disclaimer: This excerpt does not imply endorsement by DOE or the United States Government.

NIA Sites > Insulation Outlook Magazine > Global

Engineers and Specifiers: Tools and Considerations for Insulation System Design and Material Selection

The mechanical engineer is responsible for designing a commercial building’s mechanical system. This includes pipes, ducts, and equipment that distribute energy throughout the building. The objectives for insulating these components could be to save energy, maintain temperature control, protect personnel, or—on below-ambient systems prevent condensation. Most of the time, there are multiple objectives to be met. The design engineer will design and specify the insulation type(s) and thicknesses based on the objectives being considered. This article provides a step-by step approach to designing a mechanical insulation system suitable for a commercial piping project.

Regardless of the type of project, whether hot or cold, indoor or outdoor, large or small, HVAC/R or plumbing, some basic steps should be followed when designing a mechanical insulation system for a commercial project. A project will usually encompass several different applications, and possibly subgroups within an application, each of which will have to be considered separately. Before outlining the steps, a note on the overall design: One should not just specify the type and thickness of insulation to be used, but design a complete system where all the application parameters, environmental conditions, and mechanical codes will be considered, as well as the various components of the system— insulation, jacket, pipe insulation supports, adhesives, coatings, sealants, fasteners, labeling, and more—which all must be compatible and work together to  provide an application that functions efficiently. ASHRAE Handbook Fundamentals (2013), Chapter 23, Insulation for Mechanical Systems, provides general guidelines for designing a mechanical insulation system. However, each application should be evaluated based on its individual parameters and local conditions. The North American Commercial & Industrial Insulation Standards Manual (www.micainsulation.org), formerly known as the MICA Manual, goes into more detail and provides insulation design plates where the designer can fill in the type of insulation material. The Mechanical Insulation Design Guide, available at www.insulation.org/designguide, is another excellent resource for information.

Once the HVAC/R and plumbing requirements for the job have been defined and grouped by category, and the piping has been laid out, one can begin to think more specifically about the mechanical insulation requirements. However, even in this initial phase, the engineer needs to be aware of where each insulation system will be located on the project to allow the necessary space needed (e.g., distance between pipes in a run or along a wall) for the insulation system thickness (i.e., insulation plus all parts of its system, including jacketing or accessories).

The next step is to define why insulation is being installed and what outcome one hopes to achieve by insulating the piping. It is for energy savings, condensation control, maintaining process temperatures, personnel protection, or an acoustical goal? Various sub-systems may need to be broken out for special consideration. This step involves reviewing the layout of all the pipe and tubing sizes, lengths, supports, fittings, flanges, valves, and more.

Next is to identify the process temperatures of the equipment being insulated in the various applications of the job. This will narrow down the choices of insulation materials and help determine the thickness required, although this will not be the only parameter used in determining thickness. NIA’s Insulation Materials Specification Chart NIA-TIC-101 (http://www.insulation.org/specs) is an easy independent resource for reviewing the high- and low-temperature use limits on various insulation materials. Note that the guide is based on ASTM International Specifications, not individual products, so always double-check the manufacturer’s data sheet before finalizing the specific product selection. With a few exceptions, most mechanical insulation materials, although they vary in form (fibrous, cellular, granular) and composition (non-petroleum base and petroleum base) have thermal conductivity values in a relatively narrow range: 0.24–0.30 BTU (hr/sq.ft.-F), as indicated in the Insulation Materials Specification Chart. Density becomes a selection criterion when considering the specifics of how the insulation will be treated. If it is likely to undergo inevitable wear and tear or withstand pressure, then a heavier density might be chosen.

The environmental conditions of each sub-system should be defined next. The environmental conditions are usually straightforward for indoor applications but should not be taken lightly. For example, one should consider whether the conditioned spaces are always temperature- and humidity-controlled or intermittently uncontrolled. In the latter case, they must be regarded as unconditioned or uncontrolled and treated as such.

Outdoor applications involve greater extremes in temperature, humidity, and wind, and will always require some type of abuse or weather protection for the insulation system (e.g., coating, jacketing). In addition, many current mechanical codes require jacketing or coatings on exterior piping for most insulation materials to protect against ultraviolet degradation from the sun and all the other elements insulation is exposed to outdoors (e.g., wind, rain, birds, vermin, foot traffic). The type of protective covering required will depend on these and other environmental and personnel conditions, the expectation of the owner, and the cost, among other considerations.

Typically, the most extreme conditions should be designed for—unless it is completely impractical. When the extreme conditions cannot be designed for, accommodation must be made for when the design conditions are exceeded, particularly when the purpose of the insulation system is condensation control or personnel protection.

The specific insulation system (types) appropriate for a given system can be determined using the pipe and tubing size, process temperature, environmental conditions (e.g., humidity, ambient temperature), and overall goal of insulating the system. Experience and history of local insulation contractors with certain insulation materials should be considered and may also play a role in this selection process. For example, specifying a product that is difficult to obtain or unfamiliar to the local insulation contractors may result in an over-budget project on bid day.

By reviewing the insulation system requirements more closely, one can select the best insulation for the application. Ease of installation (flexibility or rigidity), project conditions, moisture resistance, fire and life safety, the need for a load-bearing component, clean room requirements, compatibility of the insulation and the type of piping being used, pipe and tubing size, cost, and more will all play a role in selecting the best insulation assemblies from the possible materials that meet the mechanical code, system conditions, and environmental condition parameters. Some engineers try to use one type of insulation on an entire project. This approach may diminish performance and may not be the most cost-effective approach. Using different types of insulation on large (over 8”) and small (run-outs) piping —even for lines that are operating at the same temperature and under the same conditions—often provides system advantages in performance and cost if compatibility is considered and the system is designed properly.

Once the insulation type has been established for the specific application, the minimum insulation thickness can be determined by the applicable current local mechanical code, which usually specifies thickness based on pipe and tubing size or process temperature, by either thickness in inches or R-value. Be careful to make sure the specified insulation thickness will meet the mechanical code requirement for the installed condition, not just the nominal manufactured factory thickness. Local mechanical codes vary and should always be double-checked to be sure they are consistent with the project’s site location. The Mechanical Insulation Design Guide (www.insulation.org/designguide) has several easy-to-use calculators that can assist.

When determining thickness for condensation control or personnel protection, environmental conditions are essential (e.g., ambient temperature and relative humidity). In addition, wind speed and the emissivity of the insulation’s outer surface/jacket (if required) play a key role in determining the thickness of the insulation required to inhibit condensation. Again, the thickness should be calculated based on the most extreme conditions, if possible, or accommodations will have to be made for when the design conditions are exceeded to prevent system failure. In addition to the insulation calculators, NAIMA’s 3E Plus® insulation software program, available at www.3EPlus.org is a valuable tool for determining insulation thickness. For more current product-specific information, many insulation manufacturers have similar programs specific to their products and may provide more accurate, updated information.

 

Thickness Myths

Also, one note of caution in determining insulation thickness: One of the easiest mistakes to make is to use the thickness recommendations for energy conservation when trying to control external surface condensation. Energy conservation thickness recommendations are not applicable for condensation prevention and can be far below what is required for condensation control in most regions. To avoid a common misstep when designing condensation-prevention systems, make sure to factor in the effect the emissivity of the insulation/jacket will have on the insulation thickness. One of the biggest myths in insulation design is to over-specify thickness instead of a needed moisture vapor retarder/barrier. Increasing the thickness will not replace a vapor-barrier system in condensation-control applications, especially under humid conditions. The proper insulation thickness will prevent exterior surface condensation, while vapor retarders will help prevent moisture migration into/through the insulation and the resulting condensation on the cold substrate surface.

 

Final Steps

The last step in the process would be to review the entire project, looking at all the applications within to ensure all design elements are working together. The layout should allow for the specified engineered insulation thickness. Take note: The number one complaint of insulation contractors/installers is that there needs to be more space for the pipe insulation system as specified. This error can lead to delays in the installation schedule or reduced insulation, resulting in reduced system performance. All system parts should be specified, including vapor retarder systems/jacketing and vapor dams (where required), pipe and tubing supports, and any other needed materials. It is also important to specify detailed explanations on how to install the insulation in difficult areas such as valves (e.g., use of removable insulation if required) and vessels.

During this step, the issue of aesthetics can also be considered. The system may function properly, but if it does not look good, it could be an issue for the owner. If uniform appearance is a particular concern, it is advisable to specify one brand type within the same room or area. Differences in brand type will likely not be noticeable in different places, but using different types of materials from various manufacturers within one room—while they may perform equally—may not look exactly alike (e.g., color [shade] variation or outer diameters not matching perfectly), which may give the appearance of a “patchwork” installation. Ideally, one manufacturer for each insulation type should be used on each system to ensure compatibility with products such as facings, adhesives, and other related items.

The use of pre-fabricated products (e.g., pre-fabricated fittings, insulation with factory applied jacketing, or the use of pre-applied adhesive to the insulation/insulation jacket) may be specified for numerous reasons, such as faster installation or better performance. Basic manufacturer installation instructions or recommendations can be part of the specification for each system, as well as a project inspection process detailing when and what should be inspected at various steps during the installation.

Product submittal sheets/data sheets should also be reviewed for compliance with engineering specifications and local code requirements. Current product data sheets should be thoroughly examined to be sure each product is compliant with all regional mechanical insulation codes for the application as well as the requirements of the insulation material standard. To be sure the insulation materials and products used in the project coincide with what was specified, a no-substitution clause can be included in the specification design. This should specify that there will not be a product substitution that could affect performance (note though, this does not mean that there can be no brand substitutions, as long as performance is the same). This will ensure that no product substitutions are allowed unless submitted to the engineer on record in writing. The rationale for the substitution, cost variances, data sheets, and product samples being proposed to be substituted must be supplied and approved 60 days before the installation. This provides assurance that the specified design will perform as intended.

 

Real Life Note of Caution

Another note of caution: Selecting an old thermal insulation system design from the engineering archives and using a cut-and-paste method to adapt it for new projects may speed up the design process, but it is also fraught with peril because of differing environmental conditions. Similarly, a design for a project that performed well in one region—for example, the cooler Northeast—may not work in the humid Gulf Coast region because of different environmental conditions or local mechanical insulation codes. This is particularly true for applications where condensation control is one of the primary goals of the insulated pipe and tubing system.

 

Conclusion

By evaluating the system at this stage of the project, you will ensure that all the materials and accessories in the system are being specified and that all the elements will be compatible and work together to provide the thermal insulation performance on the project. Following the above steps in the order designated, should help ensure the mechanical insulation system will meet the expectations of the project in a long-term, cost  efficient manner. The next step is to get a quality, professional insulation contractor who is experienced and can install the system properly. Many projects specify the requirement of a Certified Insulation Inspector™ to inspect and verify that the installation is done according to the project specification. You can find a Certified Insulation Inspector at www.insulationinspectors.com.

After the installation, there is a need for a maintenance plan or periodic inspection of the installed system to ensure proper maintenance of the system and replacement of damaged insulation, which will keep the system functioning up to expectations.

If you have an existing insulation system that may need to be brought up to code or improved, contact a Certified Insulation Energy Appraisers to receive a report on energy savings and carbon emission reductions available in your facility or plant. Insulation improvements usually pay for themselves in less than a year, freeing up operational funds for the future. You can find Certified Insulation Energy Appraisers at www.insulationappraisers.com.

 

Field Experience

As a final note, engineers, particularly those newer to the industry, are encouraged to take some time to observe insulation installation in the field. While on site, you are more likely to notice the things that need to be tweaked: the gaps, what is missing, or what is not really working. It is essential to look around at the changes in the application requirements and the products available to meet those requirements. Seeing how systems are installed, and working with insulation contractors, will improve the ability to design the best systems.

NIA Sites > Insulation Outlook Magazine > Global

What Is the Value of Insulation? Explaining k-value, R-value, U-value, and C-value

In most applications, the primary feature of a thermal insulation material is its ability to reduce heat exchange between a surface and the environment, or between one surface and another surface. This is known as having a low value for thermal conductivity. Generally, the lower a material’s thermal conductivity, the greater its ability to insulate for a given material thickness and set of conditions.

If it is really that simple, then why are there so many different terms, such as k-value, U-value, R-value, and C-value? Here is an overview with relatively simple definitions.

 

k-value

k-value is a material property that changes with temperature—it is simply shorthand for thermal conductivity. The ASTM Standard C168, on terminology, defines the term as follows:

Thermal conductivity, n: the time rate of steady state heat flow through a unit area of a homogeneous material induced by a unit temperature gradient in a direction perpendicular to that unit area.

This definition is really not that complex. Let’s take a closer look, phrase by phrase.

Time rate of heat flow can be compared to water flow rate, e.g., water flowing through a shower head at so many gallons per minute. It is the amount of energy, generally measured in the United States in Btus, flowing across a surface in a certain time period, usually measured in hours. Hence, time rate of heat flow is expressed in units of Btus per hour.

Steady state simply means that the conditions are steady, as water flowing out of a shower head at a constant rate.

Homogeneous material simply refers to one material, not two or three, that has a consistent composition throughout. In other words, there is only one type of insulation, as opposed to one layer of one type and a second layer of a second type. Also, for the purposes of this discussion, there are no weld pins or screws, or any structural metal passing through the insulation; and there are no gaps.

What about through a unit area? This refers to a standard cross-sectional area. For heat flow in the United States, a square foot is generally used as the unit area. So, we have units in Btus per hour, per square feet of area (to visualize, picture water flowing at some number of gallons per minute, hitting a 1 ft x 1 ft board).

Finally, there is the phrase by a unit temperature gradient. If two items have the same temperature and are brought together so they touch, no heat will flow from one to the other because they have the same temperature. To have heat flow by conduction from one object to another, where both are touching, there must be a temperature difference or gradient. As soon as there is a temperature gradient between two touching objects, heat will start to flow. If there is thermal insulation between those two objects, heat will flow at a lesser rate.

At this point, we have rate of heat flow per unit area, per degree temperature difference with units of Btus per hour, per square foot, per degree F.

Thermal conductivity is independent of material thickness. In theory, each slice of insulation is the same as its neighboring slice. The slices should be of some standard thickness. In the United States, units of inches are typically used for thickness of thermal insulation, so we need to think in terms of Btus of heat flow, for an inch of material thickness, per hour, per square foot of area, per degree F of temperature difference.

After picking apart the ASTM C168 definition for thermal conductivity, we have units of Btu-inch/hour per square foot per degree F. This is the same as the term k-value.

 

R-value

Typically, this term is used as a 75°F mean temperature comparison for labeled performance rating of building insulation one can buy in a big box store. It is used less frequently for mechanical insulation, but it is still a useful term to understand. Its official designation is thermal resistance. This is how ASTM C168 defines it:

Resistance, thermal, n: the quantity determined by the temperature difference, at steady state, between two defined surfaces of a material or construction that induces a unit heat flow through a unit area.

ASTM C168 then provides an equation, followed by typical units. In the inch-pound units, thermal resistance is measured in degrees F times square feet of area times hours of time per Btus of heat flow.

Most people know that for a given insulation material, the thicker it is, the greater the R-value. For example, for a particular type of insulation board, a 2-inch-thick board will have twice the R-value of the 1-inch-thick board.

Equation 2: R-value = 1 / C-value

If the C-value is 0.5, then the R-value is 2.0. One can calculate it from the equation for C-value in Equation 1 above.

Equation 3: R-value = thickness / k-value

Thus, if the thickness is 1 inch, and the k-value is 0.25, then the R-value is 1 divided by 0.25, or 4 (leaving off the units for brevity).

 

 

U-value

U-value, known officially as thermal transmittance, this is more of an engineering term used to designate the thermal performance of a system as opposed to a homogeneous material. The ASTM C168 definition is as follows:

Transmittance, thermal, n: the heat transmission in unit time through unit area of a material construction and the  boundary air films, induced by unit temperature difference between the environments on each side.

There are a few new terms: the boundary air films and between the environments on each side. The previous definitions did not refer to environments.

The best way to illustrate thermal transmittance or U-value is through an example. Consider the wall of a typical insulated house with nominal 2 x 4 boards (which actually measure about 1-1/2 inches x 3-1/2 inches), spaced 16 inches on center, running vertically. One might see 3/8-inch-thick gypsum wall board on the inside of the wall, with a plastic film vapor barrier separating the gypsum wall board from the wood studs. Fiber glass batts may fill the 3-1/2-inch-wide spaces between the 2 x 4 studs. On the outside of the studs, there might be 1/2-inch-thick polystyrene insulation boards covered with exterior wood sheathing. This example will ignore doors and windows, as well as the k-value and thickness of the plastic sheet used as the vapor barrier.

The calculation of the wall’s U-value is sufficiently complex to be beyond the scope of this article, but the following values must be known (or at least estimated) for its thermal transmittance to be calculated: *

  • C-value of the indoor air film
  • k-value of the 3/8-inch gypsum wall board
  • k-value of the 3-1/2-inch-wide wood studs
  • Spacing between the studs (16 inches, in this case)
  • k-value of the fiber glass insulation batts, as well as their thickness (3-1/2 inches thick)
  • Width of the fiber glass batts (16 inches minus the 1-1/2 inch thickness of the wood studs = 14-1/2 inches)
  • k-value of the polystyrene boards, and their thickness (1/2 inch)
  • k-value and thickness of the wood siding materials
  • C-value of the outdoor air film

* Values for all of the above can be found in the ASHRAE Handbook of Fundamentals (2021), Chapter 26, titled: “Heat, Air, and Moisture Control in Building Assemblies—Material Properties. ” Chapters 24 through 27 of the same ASHRAE manual also discuss calculation of the wall’s U-value.

The lower the U-value, the lower the rate of heat flow for a given set of conditions. A well-insulated building wall system will have a much lower U-value, or thermal transmittance, than an uninsulated or poorly insulated system.

To determine a mechanical insulation system’s U-value accurately, one must account for heat transfer through the homogeneous insulation as well as through any breaches and expansion gaps with a different insulation material. There is also the outside air film and occasionally an inside air film.

In reality, many non-homogenous portions are typically unaccounted for. The standard thermal conductivity test procedures typically treat the material as being homogeneous. In real applications, there are joints and sometimes cracks in rigid materials. These inconsistencies make the U-value greater than if the insulation behaved as a homogeneous material.

 

 

 

C-value

C-value and U-value are both used to calculate heat loss, typically with building elements, based on performance at 75°F mean temperature. C value is simply shorthand for thermal conductance. For a type of thermal insulation, the C-value depends on the thickness of the material; k-value generally does not depend on thickness (there are a few exceptions not in the scope of this article). How does ASTM C168 define thermal conductance?

Conductance, thermal, n: the time rate of steady state heat flow through a unit area of a material or construction induced by a unit temperature difference between the body surfaces.

ASTM C168 then gives a simple equation and units. In the inch-pound units used in the United States, those units are Btus/hour per square foot per degree F of temperature difference.

The words are fairly similar to those in the definition for thermal conductivity. What is missing is the inch units in the numerator because the C-value for a 2-inch-thick insulation board is half the value as it is for a 1-inch-thick insulation board of the same material. The thicker the insulation, the lower its C-value.

Equation 1: C-value = k-value / thickness

 

Conclusion

The concepts of k-value, R-value, U-value, and C-value can be summed up in the following rules:

  • The better insulated a system, the lower its U-value.
  • The greater the performance of a piece of insulation, the greater its R-value and the lower its C-value.
  • The lower the k-value of a particular insulation material, the greater its insulating value for a particular thickness and given set of conditions.

These are the properties upon which users of thermal insulation depend for energy savings, process control, personnel protection, and condensation control.

NIA Sites > Insulation Outlook Magazine > Global

Designing an Insulation System? We made it easier for you.

 

Whether you are looking for a better understanding of insulation or need to design or specify a complex insulation system, NIA’s Mechanical Insulation Design Guide (Design Guide) is a comprehensive, well-organized, and easy-to-use resource. Created to assist the novice and seasoned user alike in the design, selection, specification, installation, and maintenance of mechanical insulation, the Design Guide is continually updated with the most current and complete information.

The Design Guide leads users naturally through the engineering design process, including the following steps:

  1. Identify the need or define the problem,
  2. Gather pertinent information,
  3. Identify possible solutions,
  4. Analyze and select a solution, and
  5. Communicate the solution.
To assist insulation designers, the Design Guide is divided into sections that answer five basic questions:
  1. Why am I insulating this?
  2. What am I insulating?
  3. Where am I insulating, and what are the ambient design conditions?
  4. What materials and systems are best for this job?
  5. How much will this cost, and what is the best way to implement this solution?
This article provides an overview of the Design Guide’s contents.

Design Objectives

This section helps answer the questions why, what, and where. It discusses the potential design objectives and considerations for mechanical insulation systems. An insulation system can be designed for specific objectives, such as energy conservation or condensation control, or for multiple objectives. To select the right insulation system, you need a clear understanding of the objectives for the finished system.

The most familiar uses of insulation are to reduce heating and cooling loads, and to control noise in building envelopes. However, mechanical insulation is primarily used to limit either heat gain or heat loss from surfaces operating at temperatures above or below ambient temperature. It also may be used for the following design objectives.

 

Condensation Control

The design problem is best addressed as two separate issues: 1) avoiding surface condensation on the outer surface of the insulation system, and 2) minimizing or managing water vapor intrusion. This section of the Design Guide includes helpful tables on insulation thickness required to prevent condensation, design weather data for condensation control, as well as a design example using an outdoor chilled water supply piping serving a commercial building expansion in Tampa, Florida.

 

Energy Conservation—Financial Considerations

Mechanical insulation is commonly used to reduce the rate of unwanted heat loss or gain from/to mechanical systems and equipment. There are three primary reasons:
  • To minimize the use of scarce natural resources and their financial expense,
  • To minimize the greenhouse gas emissions associated with energy usage, and
  • To maximize return on investment (ROI) and minimize the life-cycle costs of projects.
Examples in this section include calculating ROI and a simple payback period. The section also focuses on sustainability and green buildings, providing a table on carbon equivalents for various greenhouse gases.

 

Fire Safety

Mechanical insulation materials are often used as a component in systems or assemblies designed to protect buildings and equipment from the effects or spread of fire (i.e., fire-resistance assemblies). They can include walls, roofs, floors, columns, beams, partitions, ducts, joints, and through-penetration fire stops. This section of the Design Guide highlights relevant codes and standards, and it defines terms such as noncombustible.

 

Freeze Prevention

Insulation can prolong the time required for freezing or prevent freezing if flow is maintained at a sufficient rate. This section includes information on calculating time required for water to cool in a pipe with no flow and also provides an informative table with time to cool water to freezing based on nominal pipe size and insulation thickness.

 

Personnel Protection—Safety

In many applications, insulation is provided to protect personnel from hot or cold piping and equipment. In addition, there are safety and comfort concerns related to personnel working in high-temperature, high radiant exposure locations. This section provides relevant standards as well as information related to indoor and outdoor applications, retail considerations, jacketing materials, and more.

 

Process Control

Insulation systems are often designed to minimize variation of temperatures in processes. This section highlights several common examples, including insulation on tanks or vessels and the use of insulation to minimize temperature change of a fluid from one location to another.

 

Noise Control

Insulation is often specified on mechanical systems and equipment to control noise within buildings and other facilities. Topics in this section include noise radiating from pipes, noise from ducts, and breakout noise.

Other factors to consider when designing a mechanical insulation system include:

  • Abuse resistance,
  • Corrosion under insulation,
  • Indoor air quality,
  • Maintainability,
  • Regulatory considerations,
  • Service and location, and
  • Service life.

Materials and Systems

In most cases, one can choose from multiple types of mechanical insulation materials for any given application. The Materials and Systems section discusses material categories and provides links to additional information and to the material manufacturers. The list changes continually as existing products are modified, some products are phased out, and new products are developed.

In addition to commonly used materials, this section also describes important performance or physical properties for insulation materials and associated weather barriers, vapor retarders, and finishes.

The Design Guide categorizes mechanical insulation materials into the following major types (listed alphabetically):

  • Cellular,
  • Fibrous,
  • Flake,
  • Granular (flexible and rigid), and
  • Reflective.
Selecting an insulation material for a particular application requires understanding the physical properties associated with insulation materials. This section provides an overview of 13 properties, from alkalinity to wicking. It also provides links to specific material data, including submittal sheets.

 

Installation

Installation of mechanical insulation is typically managed by experienced contractors who specialize in the mechanical insulation sector of the commercial, industrial, and HVAC sectors of the construction industry. Within this section, the Design Guide covers pre-work considerations, securing methods, finishes, special considerations, and inspection and maintenance.
The Mechanical Insulation Installation Video Series (in English and Spanish) is available to provide a general overview and basic how-to guide for mechanical insulation applications. The complete list is available in NIA’s Online Store and from NIA’s Education Center (https://niaeducationcenter.org/courses/47932#).

 

Design Data

This section of the Design Guide contains information on estimating heat loss and gain, controlling surface temperature, determining dimensions of standard pipe and tubing insulation, and estimating heat loss from bare pipe and tubing. Users also will find seven useful tables covering a range of design-related concerns and calculations.

 

Specifications

The mechanical insulation specification is an important but often overlooked part of the overall design process. Good specifications should communicate the design objectives, materials, thicknesses, finishes, securements, and other systems requirements. Specific topics covered in this section include formats, methods of specifying, scope of work, specification language, coordination with drawings and other specification parts, as well as ensuring adequate clearance for proper insulation installation and application.

 

Education on Demand

If you are looking for basic insulation education, the online Mechanical Insulation Basics (formerly known as “Mechanical Insulation Education and Awareness Campaign E-Learning Modules”) series includes practical data and case studies outlining potential energy savings provided by mechanical insulation installation. The course is designed for both industrial and commercial markets utilizing mechanical insulation systems for piping and equipment in both hot and cold applications, refrigeration and other low-temperature piping and equipment applications, as well as Heating, Ventilation, and Air Conditioning (HVAC) applications. Subjects include:
  • The principles of understanding energy,
  • What the various types of insulation are,
  • How insulation works,
  • How to design an insulation system and specify materials,
  • How the insulation calculators work and are designed for the unique needs of insulation contractors and engineers, and
  • How to oversee maintenance to keep a facility running smoothly.
The self-paced series is available at www.insulation.org/basics through NIA’s Education Center The course is a prerequisite for the Understanding Mechanical Insulation learning program, and NIA offers professional development hours (PDHs) for its completion.

 

Insulation Calculators

The Design Guide offers access to eight easy-to-use insulation calculators related to various design objectives.
  • Condensation Control Calculator—Horizontal Pipe estimates the thickness of insulation required to avoid condensation on the outer surface of an insulated horizontal steel pipe.
  • Energy Loss Calculator for Equipment (Vertical Flat Surfaces) estimates the heat flow through a vertical flat steel surface (typical of the sides of a large steel tank containing a heated or cooled fluid).
  • Energy Loss Calculator for Horizontal Piping estimates the heat flow through horizontal steel piping.
  • Financial Returns Calculator provides a convenient way to estimate the financial returns related to investments in mechanical insulation. Options include Simple Payback in Years, Return on Investment (ROI), Net Present Value (NPV), and Annual and Cumulative Cash Flow.
  • Estimated Time to Freezing for Water in an Insulated Pipe estimates the time for a long, fluid-filled pipe (no flow) to reach a freezing temperature.
  • Controlling Surface Temperature with Insulation (Personnel Protection) estimates maximum contact exposure time with the outer surface of a horizontal pipe insulation system based on the potential for contact burn injuries.
  • Temperature Drop for Air in an Insulated Duct Calculator estimates the temperature drop (or rise) of air flowing in a duct.
  • Temperature Drop for Fluid in an Insulated Pipe Calculator estimates the temperature drop (or rise) of air flowing in a pipe.

 

Resources, Case Studies, Glossary, and Update Summary

The Design Guide links to resources from NIA; American Society of Heating, Refrigerating and Air-Conditioning Engineers; American Society for Testing and Materials; National Fire Protection Association; Underwriters Laboratories; manufacturers by product type; and many more sources for information. Case studies, a glossary, and a summary of updated notes also are included.

 

Hosted by NIA, the Voice of the Insulation Industry

The Design Guide was developed by the National Institute of Building Sciences and NIA with contributions from 15 organizations, 60 manufacturers and fabricators, and 12 contractors, as well as the involvement of more than 100 individuals. The Design Guide is an unbiased, comprehensive, living resource to assist engineers, specifiers, facility owners, insulation contractors, and other users of mechanical insulation systems with a wide range of industrial and commercial applications.

NIA is committed to being the insulation industry’s leader in education. Through access to this comprehensive guide, NIA continues to pave the way to improve the quality of insulation systems nationwide. Results show the value and ROI of having properly engineered, installed, and maintained mechanical insulation systems that conserve energy, reduce emissions, improve processes and productivity, reduce life-cycle costs, and protect personnel.

The Design Guide can be accessed at www.insulation.org/designguide.

NIA Sites > Insulation Outlook Magazine > Global

A Guide to Changes in the 2024 Edition of NFPA 101

NFPA 101 Insights

NFPA 101: Life Safety Code (available at www.nfpa.org/codes-and-standards/nfpa-101-standard-development/101) is published by National Fire Protection Association® (NFPA®).

  • The 2024 edition of NFPA 101 introduces changes that address emerging trends and
    challenges in building design and safety.
  • The revised NFPA 101 places increased emphasis on occupant empowerment and early fire response, requiring fire extinguishers in new and existing assembly occupancies.
  • Important changes also include modular rooms, carbon monoxide detection, and alternative care sites (ACS).

NFPA 101 has long stood as one of the most widely used resources for protecting people and mitigating the impact of fire and related hazards. The code is updated every 3 years, so it is important to understand the 2024 edition of NFPA 101 as jurisdictions begin to work the code into their regulations. Ahead of implementation, it’s critical that engineers are aware of changes and additions contained in the new edition.

Modular Rooms and Sleep Pods in NFPA 101

Whether an office building or airport is looking to add a private space to take a phone call, be used as a lactation station or provide sleeping arrangements, modular rooms have become more popular. A modular room is an occupiable, prefabricated structure consisting of walls and a ceiling. It may or may not have an integrated floor and integral electrical wiring, ventilation, and furnishings. Modular rooms are limited to 100 square feet or less in area and 8 feet or less in height. Anything larger must be treated like any other portion of the building and comply with the applicable requirements from NFPA 101 and the building code.

A sleep pod is also an occupiable, prefabricated structure that might include integral electrical wiring, ventilation, and furnishings. However, it is specifically designed and used for sleeping purposes. When installing sleep pods, it is important to consider how their addition impacts the occupancy classification of the existing space. Because they add sleeping accommodations, their use cannot be considered incidental per NFPA 101.

For example, if an office building is adding sleeping pods, additional safeguards may be required because sleeping occupants are not expected in a business occupancy. These pods are 32 square feet or less in area, 8 feet or less in height, and 4 feet or less in width. Similar to modular rooms, if the sleeping pod is larger, it must comply with applicable requirements from NFPA 101 and the building code.

Both modular rooms and sleep pods must be listed and labeled in accordance with UL 962, Household and Commercial Furnishings. Careful consideration must be given to where these prefabricated rooms are installed. They cannot obstruct the required means of egress for the existing space. Additionally, they must be installed in accordance with the listing and the manufacturer’s instructions.

NFPA 101 Changes to Alcohol-Based Handrub (ABHR) Dispensers

ABHR dispensers became increasingly popular during the pandemic, as the global crisis highlighted the need for them in a variety of occupancies. There are two major changes to ABHR dispensers in the 2024 edition of NFPA 101. The first is an increase in the amount of ABHR permitted and the second is the addition of spill containment and maintenance requirements. The updates clarified that these provisions do not apply to individual use containers that are 16.9 ounces or smaller in size.

It’s also important to note that the requirements for ABHR dispensers in health care and ambulatory health care occupancies did not change. The changes mentioned here only apply to occupancies, such as business, mercantile, educational, and assembly buildings that require compliances with the provisions in Chapter 8.

The amount of ABHR solution permitted to be in use in fully sprinklered buildings has doubled. The previous limit was 10 gallons and is now up to 20 gallons that are permitted. There was also an increase in the allowable size of individual dispensers:

  • In corridors and areas open to corridors: increased from 0.32 gallons to 0.53 gallons.
  • In corridors and areas open to corridors in buildings protected throughout by sprinklers: increased from 0.32 gallons to 1.06 gallons.
  • In rooms or suites of rooms: Increased from 0.53 gallons to 1.06 gallons.

NFPA 101-2024 also adds requirements for spill containment and maintenance. Spill containment must be provided and kept clear of trash and ABHR solution. If any ABHR is spilled when refilling the dispensers, the spill must be cleaned up and removed as soon as refilling is complete.

NFPA 101 Increases Portable Fire Extinguishers

While many occupancy classifications required fire extinguishers per a building or fire code, they often were not a part of NFPA 101. Previous reasoning has been that NFPA 101 is primarily concerned with getting occupants out of the building, and therefore does not expect occupants to delay egress to try to extinguish a fire. However, in the 2024 edition of NFPA 101, both new and existing assembly occupancies now require portable fire extinguishers.

This change was based on findings from research studies, which identified that occupants will try to extinguish a fire in its early stages to avoid embarrassment, inconvenience, and damage to the premises or property. The research also found that concerns for people, pets, and possessions are strong drivers of behavior in the event of a fire. Studies have shown that people will almost always attempt to extinguish a fire if it’s small enough and they believe they can mitigate the hazard. If a fire extinguisher is not available, people typically use makeshift means to try to extinguish the fire, which is far less safe than using a portable extinguisher. Thus, it is important to give the public the tools necessary to be successful.

Carbon Monoxide Detection Changes in NFPA 101

The scope of NFPA 101 has expanded over the years to include non fire-related emergencies. Previous editions required certain occupancies to have carbon monoxide detection, though it was often limited to residential occupancies.

A 2022 report from the Fire Protection Research Foundation, Carbon Monoxide Incidents: A Review of the Data Landscape, led to some recommended changes in the 2024 edition of NFPA. Notably, the 2024 edition requires carbon monoxide detectors in certain areas in existing educational and day care occupancies, as well as in new health care, ambulatory and detention and correctional occupancies.

NFPA 101 Now Covers Inflatable Amusement Devices

The provisions will apply to inflatable amusement devices both inside and outside a structure, but not to one- and two-family dwellings. Typically, these devices are constructed and maintained in accordance with the ASTM F2374, Standard Practice for Design, Manufacture, Operation and Maintenance of Inflatable Amusement Devices.

There are two major concerns with such devices: anchoring and fire safety. ASTM F2374 primarily addresses the anchoring issue, although a variety of other topics are also covered. The requirements in NFPA 101 were added to address the issue of fire safety, including the materials of construction, the materials associated with electrical wiring and portable generators if they are to be provided. Key points are:

  • Devices must be constructed in accordance with manufacturer’s instructions and ASTM F2374.
  • Devices must be constructed of noncombustible materials or materials meeting the flame propagation criteria of Test Method 2 of NFPA 701, Standard Methods of Fire Tests for Flame Propagation of Textiles and Films.
  • Any electrical equipment associated with the device must comply with NFPA 70: National Electrical Code (NEC).
  • If a portable generator is to be provided, it must comply with NFPA 37: Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines and portable fire extinguishers must be in accordance with NFPA 10: Standard for Portable Fire Extinguishers must be provided.

NFPA 101 Defines Alternative Care Sites (ACS)

ACS changes were in response to the pandemic, when it became necessary for non-health-care facilities to serve as health-care facilities during patient surges. Per the newly added definition, an ACS is any building, structure, or portion thereof not currently being used for health care that is temporarily reoccupied, converted, constructed, or relocated for health-care use to provide additional capability for an affected community during urgent needs for increased capacity.

A newly created annex expands the definition of ACS and provides the user with recommendations for how to establish and operate these facilities as temporary health-care facilities. The information found in Annex D supports new language in Chapters 18 and 19, which permit ACS, provided they have an approved fire emergency plan and comply with approved alternate construction, design, protection, operational, and occupancy classification requirements.

Annex D provides sections on the following:

  • Site assessments: Considerations of a site assessment include the number and type of patients supported, proximity to nearby hospitals, personnel staffing requirements, utility requirements, air filtration and handling capacities, safety features for emergency response and egress, and staging of ambulances and parking.
  • Construction: Considerations include coordination of construction, items necessary to expedite construction related to design deliverables and product submittals, alternate means of occupant safety when compliance with health-care facility requirements cannot be met, interim life safety measures for construction adjacent to occupied areas, and authority having jurisdiction approval.
  • Operations and maintenance: Considerations include maintenance of life safety systems, fire watch, building services, operating features and inspection, and testing and maintenance of fire protection systems.
  • Facilities decommissioning: Upon completion of use of ACS, added utilities to support ACS must be removed, and the occupancy must be returned to original existing occupancy classification.

Interior Exit Discharge Requirement Changes

Typically, exits must terminate directly outside. However, that is not always possible or desirable. Prior editions of NFPA 101 had a couple of exceptions, one of which permitted up to 50% of the required exit enclosures and 50% of the capacity to discharge through the inside of a building.

The 2024 edition of NFPA 101 expands one of those conditions and allows up to 75% of the required number of exit enclosures and capacity to be permitted to discharge through the interior, provided that:

  • The level of discharge is protected throughout with automatic sprinklers.
  • The interior exit discharge only occurs in a vestibule or foyer that is separated from the remainder of the floor by 1-hour fire-resistance-rated fire barriers (existing installations of wired glass in steel frames is permitted in lieu of the fire barriers).
  • The vestibule or foyer is not more than 10 feet from the exterior of the building and not more than 30 feet in length.
  • The vestibule or foyer only serves as a means of egress and must exit directly to the outside.

How NFPA 101 Balances Security and Life Safety

In the past, there has been a misconception that security and life safety are in opposition, in that when prioritizing life safety, security is overlooked, and vice versa. Over the past few editions, changes have been made to address this perceived conflict between security and life safety.

The 2024 edition of NFPA 101 requires that emergency action plans consider the security features in place. This helps ensure both safety and security are considered when developing plans for emergency response. New and existing educational and day care occupancies added additional language, reiterating that both security and life safety need to be considered and documented in the emergency action plan.

The Future of Life Safety Code

The changes listed in this article are by no means exhaustive, but it is hoped that they provide a helpful summary of key updates. NFPA 101 can be thought of as a living, breathing document that evolves alongside construction and operational trends. The changes made every 3 years are meant to create safer structures and environments, as well as address new challenges, making it critical for engineers to stay up to date.

Val Ziavras, PE, is a Senior Engineer in the NFPA Technical Services Division. NFPA has been helping to solve some of the planet’s toughest safety problems for more than 125 years, including fire prevention, wildfire preparedness, and electrical safety, as well as hazardous materials, community risk reduction, and public safety. This article has been reprinted from https://www.csemag.com/articles/a-guide-to-upcoming-changes-in-the-2024-edition-of-nfpa-101.

 

NIA Sites > Insulation Outlook Magazine > Global

Safety Updates

On January 16, 2024, in the case of Warren v. U.S. DOL in the U.S. District Court for the Northern District of Georgia involving a challenge to the DOL’s Independent Contractor Rule, four freelance writers/editors sued the Department of Labor claiming the Independent Contractor Rule amounts to a concerted effort to force them into employment relationships they neither want nor need. On July 24, 2024, the court received submissions of cross-motions to dismiss the complaint. Before that, several amicus (friend of the court) briefs were filed. The court has not yet issued a decision on the cross-motions to dismiss.

The Sixth Circuit Court of Appeals issued a decision on January 31, 2014, in Fisher v. Airgas that an employee out on cancer leave who used a hemp-based product called “Free M” for relief of treatment pain took a random drug test and tested positive and was terminated. The employee sued and won, and the company appealed this decision to the Sixth Circuit Court of Appeals. The company relied on the “honest belief” doctrine. This doctrine shields companies from liability for allegedly discriminatory employment actions if they offer legitimate reasons based on incorrect information that they reasonably trusted at the time they made the decision. The Court of Appeals ruled against the company and stated that the company could not rely on the “honest belief” doctrine without adequately investigating that the employee’s use of the hemp could have caused a false-positive test result.

In another challenge to the Independent Contractor Rule, on February 8, 2024, Frisard’s Transportation, LLC v. U.S. DOL in the Eastern District of Louisiana suit was filed by the Liberty Justice Center and the Pelican Inst. Co. for Public Policy on behalf of the company. The company employs 30 independent owner-operator drivers in the State of Louisiana. The current status of this case as of July 3, 2024, in order to stay and administratively close the case was issued by the court. However, the plaintiffs notified the court of their intent to appeal the court’s previous order denying their motion for a temporary restraining order and preliminary injunction. The plaintiffs have since filed an appeal at the United States Court of Appeals for the Fifth Circuit. As of August 26, 2024, the current status of the Independent Contractor Rule is that amicus curiae briefs are being filed in the appellate case.

The Pregnant Worker’s Fairness Act (PWFA) was issued as a final regulation on April 15, 2024, by the EOCC. Numerous examples of reasonable accommodations under this act include additional breaks to drink water, eat, or use a restroom; a stool to sit on while working; time off for health care appointments; temporary reassignment; temporary suspension of particular job duties; telework; or time off to recover from childbirth or miscarriage. There is currently a lawsuit brought by 19 states against the regulation. Also, 23 other states have filed a brief in defense of the regulation. Oral argument took place on June 3, 2024, and on June 21, 2024, and an order was issued denying a motion for an injunction pending appeal. The PWFA remains in force while appeals concerning challenges are litigated.

On April 17, 2024, the United States Supreme Court heard Muldrow v. City of St. Louis about a plainclothes police officer who was transferred to a lesser position that has the same pay rate, but different hours and duties sued claiming sex discrimination. A lower court tossed out the case saying that the plaintiff did not suffer any significant harm to build or bring the suit. The Supreme Court disagreed stating that a worker does not have to show that the harm incurred by sex discrimination was significant or serious.

The Sixth Circuit Court of Appeals issued a decision on April 29, 2024, regarding an Americans with Disabilities Act (ADA) accommodations request. In the case of Yanick v. the Kroger Co., a bakery worker returned to her position after breast cancer leave with her doctor’s OK to return to full duty. However, she struggled with certain tasks and was demoted. She filed an ADA lawsuit and the court sided with her saying the employer should have inferred that her comments about her physical struggles amounted to a request for an ADA accommodation. The takeaway from this decision is that as with the the Family and Medical Leave Act, employees do not need to say any magic words to request an ADA accommodation. You should ensure your managers know what may qualify and elevate subtle requests by an employee to the level of accommodations.

On June 28, 2024, the Supreme Court in a decision titled Loper Brite Enterprises v. Raimond held that judges cannot defer to a government agencies interpretation of the law. Instead, judges must exercise “independent judgment” and give statutes their “best meaning.” Judges can still consider agency guidance when that guidance is persuasive, long-standing, and consistent. But they cannot treat that guidance as “binding.” They must interpret statutes for themselves. This decision could make it harder for agencies to make rules. For example, instead of defending their rules as “reasonable” interpretations of a statute, they will now have to defend the rules as the “best” interpretations of the statute, and in court, they will be on equal footing with parties trying to challenge the rules. This decision overturned the Chevron rule.

In an interesting decision on July 1, 2024, the United States Supreme Court ruled in Corner Post, Inc. v. the Board of Governors of the Federal Reserve System that the statute of limitations for challenging the rule under the Administrative Procedures Act (APA) begins to run only when the challenger has been injured by the rule. The previous statute limitations that was applied stated that the 6-year statute of limitations began when the act became a final rule. The ruling means that a challenger can sue to block a rule that has been on the books for many years.

On August 30, 2024, the Biden–Harris administration published a proposed rule to protect indoor and outdoor workers from extreme heat. As indicated in the standard, the heat injury and illness prevention standard will require employers to develop an injury and illness prevention plan (HIIPP) to control heat hazards in workplaces affected by excessive heat. The plan would require employers to evaluate heat risks and the risk to workers and implement requirements for drinking water, rest breaks, and controlling indoor heat. As for outdoor workers, a heat illness prevention plan will have to be developed for each work site.

On September 4, 2024, the Federal Trade Commission’s new rule banning noncompetes went into effect. Challenges have been made against the new standard, however, in only one case was an injunction granted and that injunction was limited to the parties to the lawsuit. That injunction was granted in the Northern District of Texas. In a similar case filed in the Eastern District of Pennsylvania, the court denied the request for an injunction. So while legal challenges are pending, the noncompete ban is in full force and effect.

Finally, OSHA recently issued its top 10 most strictly cited workplace safety standards for FY 2024. They are as follows:
1. General Requirements for Fall Protection (1926.501)
2. Hazard Communication (1910.1200)
3. Ladders (1926.1053)
4. Respiratory Protection (1910.134)
5. Lockout/Tagout (1910.147)
6. Powered Industrial Trucks (1910.178)
7. Fall Protection – Training Requirements (1926.503) (specifically 1926.503 (a) and (b)
8. Scaffolding (1926.451)
9. Personal Protective and Lifesaving Equipment – I and Face Protection (1926.102)
10. Machine Guarding (1910.212)

NIA Sites > Insulation Outlook Magazine > Global

Data Mining—A Great Tool to Identify Key Safety Focus Areas

It is widely accepted that the most effective way to identify opportunities to reduce employee exposure to safety risks is by performing proactive risk assessments and other audit and assessment activities. It is always better to identify, reduce, and eliminate risks and hazards before an injury occurs. Having said that, we should not discard what has happened in the past. Often, a review of historical injury and incident data reveals trends that will continue to impact the safety of our workers if sustainable controls are not implemented. Known as “data mining,” this approach is used by many experienced safety professionals to identify key safety focus areas.

An important step for the analysis of injury/incident data is determining what inputs should be captured. These can vary greatly, depending on the work performed and the types of risks present in the workplace. At Johns Manville, the incident management database used to capture this data may seem a bit overwhelming for a new safety professional because many inputs are required to be entered. However, this multitude of input data allows for injury/incident trends to be analyzed in countless ways.

Examples of Data and Trend Analyses

The following figures provide examples of data trend analyses and the conclusions that were drawn from them.

Figure 1 shows that in this organization, the fingers and hands were the most frequent body parts injured. This data led the organization to create a special emphasis program aimed at reducing the number of hand and finger injuries. (The total number of injuries has been removed for confidentiality reasons).

Figure 2 shows a multitude of different injury types. At first sight, it is possible to conclude that no clear pattern stands out. However, a closer look shows that two of the top four injury types are directly related to ergonomic stressors (discomfort and sprain/strain). As a result, the organization moved to perform more ergonomic risk assessments to identify ergonomic improvement opportunities. (Again, the total number of injuries has been removed for confidentiality reasons).

Data analysis also showed that newer employees (less than 1 year of tenure) suffered injuries at a far higher rate than injuries that occurred in the total workforce. This disproportionality led the organization to improve and standardize the employee onboarding process. The data also helped guide how the organization selects trainers from within the tenured group to provide on-the-job training to the newer employees.

Conclusion

Because risk assessments, hazard analyses, and other hazard identification tools are proactive and are performed before an injury or incident occurs, they are the preferred methodology for injury prevention. However, data mining (the review of historical injury and incident data) may reveal injury trends that can also help us to identify key safety focus areas.

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Understanding Passive Fire Protection and the Growth Impacts to the Insulation Industry

One of the least understood technical concepts, yet potentially the most impactful opportunity for organic growth of the mechanical insulation industry, is passive fire protection (PFP). Engineers and asset owners can realize significant benefits in terms of safety, reliability, environmental compliance, operational efficiency, and compounding savings on energy inputs and insurance expenses. Manufacturers, distributors, fabricators and contractors can benefit from installing insulation and metal jacketing within industrial plants on assets that may have never been insulated.

The first concept to understand is the difference between the two primary types of PFP: structural versus pressure-relieving systems. Historically, these two design methodologies have often been conflated in marketing and technical bulletins, causing confusion among stakeholders.

Structural PFP is designed to protect structural steel skeletons that support pipe racks, vessels, and equipment above ground level (see Figure 1). Typically specified materials used for structural PFP are cementitious or intumescent epoxy coatings, spray-applied to steel elements such as I-beams, columns, and girders. Endothermic wraps or fire- protection boards are less common and more costly, but they are removable for corrosion under fireproofing (CUF) inspection. Structural steel loses about half of its load-bearing capacity at 1,100°F. Therefore, structural engineers must specify the number of minutes (typically 120 to 240 minutes) the steel skeletons can withstand a fire event so firefighters can evacuate well before a catastrophic collapse of the structure.

There are two test methods regarding fire protection for structural steel: UL 1709 – Rapid Rise Fire Tests of Protection Materials for Structural Steel and ASTM E1529 – Standard Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and Assemblies. Simply stated, these tests answer the question: How many minutes will it take to increase the temperature of a specific steel member protected with a specific thickness of PFP material from ambient to 1,000°F inside a 2,000°F furnace? Thicker/heavier steel requires thinner PFP material and thinner/lighter steel requires thicker PFP material to achieve the same number of minutes of fire protection.

The second application for PFP—pressure-relieving system applications—is much less
understood, and it is the focus of the balance of this article. It is incumbent on the industry to understand and be clear when discussing this topic with engineers and facility operators by not conflating unrelated structural steel PFP test methods such as UL 1709 with pressure-relieving system applications. With few exceptions, mechanical insulation and metal jacketing is not historically specified for structural steel PFP, in favor of the more labor-friendly and cost-effective solutions mentioned above. In short, we should focus efforts on pressure-relieving applications to create organic and long-term sustainable demand for more mechanical insulation, metal jacketing, and skilled labor to install them.

The American Petroleum Institute (API) is an industry association of more than 600 member companies. According to www.api.org, “API represents all segments of America’s oil and gas industry,” and “API’s mission is to promote safety across the industry globally…” API publishes numerous consensus standards documents to assist engineers and plant operators to increase safety and promote best practices to decrease risk. One such document is titled “API Standard 521 Pressure-Relieving and Depressuring Systems.” This copyrighted document must be purchased from API or one of its authorized distributors.

API 521 is the governing document when discussing PFP that involve pressure-relieving systems. First, one needs to understand the concept in simple terms. If a fire breaks out in an industrial plant, there are many highly volatile and explosive fluids (liquids or gases) that will get hot very quickly. What happens when fluids heat up? They expand, which increases pressure inside the pipe or storage vessel. This excess pressure needs to be released, and the fluids quickly conveyed away from the fire, using specialized and costly pressure-relieving valves (PRVs) to avoid an explosion and further propagation of the fire (see Figure 2).

In industrial plants, traditional methodology assumes that during a fire outbreak, an emergency pressure-relieving event is inevitable due to the rapid heating and vaporization of stored volatile fluids. This time-tested system ensures the rapidly heated stored fluids are quickly released by PRVs into liquid knockdown drums and flashback seal drums, with the excess gases quickly burned off by a flare stack (see Figure 3).

A good analogy to this concept is a pressure cooker like those that can be found in many kitchens. These mini sealed pressure vessels quickly cook foods like beans, potatoes, and beef stew by combining heat and above-atmospheric pressure. The key to this kitchen gadget is a small PRV on the lid that sputters and emits steam with a pleasant, rhythmic hissing sound I remember fondly from my childhood. A PRV is also installed on home water heaters to release excess pressure, which prevents your water heater tank from becoming a missile and blowing a hole in your roof!

One of the lesser known and understood sections of the API 521 standard document is section 4.4.13.2.7 External Insulation. It states (bold emphasis added):

Credit for thermal insulation is typically not taken because it usually does not meet the fire-protection insulation requirements given in 4.4.13.2.7.2 through 4.4.13.2.7.4. If these requirements are met, a reduction in fire input can be obtained by using the environmental factor.

While it is true that most industrial insulation systems do NOT meet the requirements, it is also clear that systems CAN be designed with the correct components to withstand the extreme fire-protection conditions listed in the report.

Succinctly stated, a properly designed and professionally installed insulation system can be utilized to dramatically limit the rapid heat gain in a system during a fire. In a real sense, one can buy time to “slow the pot from boiling” in the first place. As Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.”

Section 4.4.13.2.7.2 clearly outlines the requirements of the insulation SYSTEM for it to qualify as “fire-protection” for the purposes of reducing the potential of a rapid expansion of stored fluids during a fire outbreak. The system includes insulation, attachment method, metal cladding, and any accessories to help the system remain attached and intact, to protect the vessel from rapid heat gain during a fire. This method may allow for a reduction in the cost and footprint of the pressure-relieving and flaring system.

Section 4.4.13.2.7.2 states that the physical property requirements of the insulation system are as follows:

  • The system must be able to function effectively at temperatures up to 1,660°F for up to 2 hours.
  • Corrosion under insulation must be considered when installing any insulation.
  • The system must remain intact and not be dislodged by high-pressure water streams during firefighting operations.
  • The insulation system must be able to withstand direct flame impingement.
  • The insulation system must be attached with stainless steel bands and then clad with stainless steel jacketing.
  • Aluminum banding and/or jacketing is NOT acceptable because it will melt at 1,220°F.

According to several metal jacketing suppliers, about 90% of mechanical insulations installed in industrial plants are clad with aluminum jacketing due to the lower cost compared to stainless steel jacketing (25 to 30% Δ). This fact explains the statement in API 521, “Credit for thermal insulation is typically not taken because it usually does not meet the fire-protection insulation requirements.” By specifying T-304 stainless steel bands, wing seals, and cladding with a melting point greater than 2,500°F, this ensures the insulation system can withstand the extreme temperatures and hold the insulation on the asset (see Figure 4.) Stainless steel expansion or compression springs installed on the outer bands of large vessels keep the bands tight during operations and can help the insulation remain attached during a fire event.

Table 6 of API 521, reproduced here in Figure 6, lists five different types of generic insulations (Figure 5). Please note that Table 6 should not be considered an “approved list” or all-inclusive of every type of generic insulation material that could be specified by an engineer in conjunction with stainless steel jacketing for this application. At the same time,
certain other types of insulations that cannot withstand extremely high temperatures should not be considered for this application. In this author’s experience, the most common error in the engineering community in specifying “fire protection insulation” per API 521 is confusing maximum continuous operating temperature versus a 2-hour excursion temperature of 1,660°F during a fire event, as listed in the API requirements. If one misunderstands this key difference, then the only insulation that would apparently suffice would be type II calcium silicate with a continuous operating temperature of 1,700°F. API’s Table 6 lists several other generic types of insulation with maximum continuous operating temperatures between 900°F and 1,200°F that will all survive a 2-hour excursion event when attached/clad with stainless steel bands/jacketing. Several other generic types of insulation not listed in Table 6 could also be specified as a component in a fire-protection insulation system per API 521. Hybrid systems using more than one type of generic insulation also could be considered. Engineers should contact manufacturers of materials not listed in Table 6 for specific performance and recommendations for this specialized application.

For the purposes of this overview, which focuses on benefits to the insulation industry and its end users, we will not discuss in detail the process for determining the thickness required to slow the rapid heat gain during a fire or to potentially reduce the cost and footprint of pressure-relieving systems. At a high level, engineers must calculate the anticipated heat gain at much higher mean temperatures that often exceed the required maximum mean temperatures to be reported per the various ASTM material standards (typically 700°F mean or lower). One specific takeaway to consider is for insulation manufacturers promoting their materials for API 521 applications to invest in testing and publishing measured thermal conductivity values at higher mean temperatures—perhaps up to 1,100°F mean, as an example.

Here is a concrete illustration of how utilizing a properly designed fire-protection insulation system per API 521 can provide immediate and long-lasting return on investment (ROI) for an industrial plant operator. The average age of an oil refinery in the United States is 74 years old. As safety standards have increased over time, insurance carriers have also increased their fire-protection requirements for owners. One such refinery in the western United States was faced with a costly expansion of their pressure-relieving system as a condition of their insurance carrier continuing coverage. The refinery had a large pressure vessel with one 2”-thick layer of type I calcium silicate insulation, which was clad with aluminum jacketing. By employing the design methodology in API 521, plant engineers were able to plan and execute a project that removed the aluminum jacketing and added one more layer of 2”-thick insulation that was then clad with new stainless steel jacketing. Using this smart strategy, the owner was able to meet the insurance company’s new requirements without upgrading to larger PRVs along with an expanded flare disposal system. The owner reported the cost difference between the two options was over a million dollars and improved the thermal efficiency of the pressure vessel!

Conclusion

Mechanical insulation is well known for its myriad benefits, including process control, worker protection, and reduced energy consumption and greenhouse gas emissions—all while providing extremely short payback periods and compounding ROI. Fire-protection insulation systems per API 521 provide one more valuable benefit for owners to consider as part of their overall risk management strategy.

NIA Sites > Insulation Outlook Magazine > Global

Designing District Energy Systems for Longevity

District energy systems are becoming more commonplace as a practical HVAC solution for populated environments with a high demand for heating and cooling solutions. Today’s universities, hospitals, and municipal complexes commonly rely on a district energy system’s central plant to generate chilled water, hot water, and steam, and distribute them via a network of pipes to energy users in the buildings throughout the district.

District energy system piping is usually “direct buried” under soil or housed in underground tunnels and vaults. These environments often can present harsh conditions that can lead to problems within pipe insulation systems, including reduced thermal performance, corrosion under insulation (CUI), and added stress to underlying equipment and infrastructure. These issues could be due to suboptimal material selection, improper installation, or damage that takes place during operation.

In this article, we will explore factors to consider regarding insulation systems to support the longevity and efficiency of district energy systems.

Challenges with Chilled Water Lines

The chilled water lines within district energy systems typically will operate within a given temperature range. This could be as low as 36°F (2°C) for chilled water supply lines and up to 55°F (13°C) for return lines. Given these below-ambient temperatures, there is usually an ever-present vapor drive that wants to condense water vapor from the air into liquid water condensation on the pipe’s surface. Insulation systems rely on the integrity of a vapor barrier to prevent water buildup from occurring within them. If that vapor barrier were to become compromised, the system would be subject to moisture intrusion that could bring about a variety of issues that could remain hidden for years before being discovered.

Moisture ingress into the insulating system is a key concern in chilled water applications. In the case of absorbent insulations, liquid moisture can collect within the insulation material. Insulation systems often rely on the presence of air gaps within their structure to maintain their declared thermal conductivity values. If these insulation materials become saturated with water, it leads to significant degradation of their thermal properties, resulting in thermal bridging, which can increase heat gain into the underlying chilled water lines. This situation can lead to energy losses and increased costs, as more energy is required to cool pipes back down to their intended operating temperature. It also puts added stress on equipment such as chillers, potentially degrading their service life.

Another byproduct of introducing moisture into an insulation system involves the potential for CUI. For corrosion of carbon steel to occur, certain ingredients must be present—the most fundamental of which are the presence of oxygen and an electrolyte (such as liquid water). Oxygen is almost always readily available, whether it be from the air or dissolved in water itself. Therefore, if liquid water is introduced onto a carbon steel surface, the risk of corrosion becomes immediately present. Corrosion can damage the outside of pipes over the span of multiple years; and, in the most catastrophic instances, it can result in failure of an entire piping system.

In addition to preventing moisture from penetrating into insulation, it is also important to maintain a surface temperature of insulation that will prevent surface condensation, or
“sweating,” from occurring. If water is allowed to condense on the outside of an insulation system, it can contact nearby metal equipment and lead to corrosion, or potentially work its way through a system’s vapor barrier, leading to the previously mentioned issues. The goal when designing an insulation system for chilled water lines is always to ensure that the surface temperature of the insulation system will be greater than the dew point of the surrounding air. One way to achieve this is to ensure a sufficient thickness of insulation material is used, based on the operating temperature and humidity of the local environment. This can be determined during the engineering design phase of a system through an energy analysis calculation.

Another design consideration that can affect the presence of surface condensation is the emissivity of an insulation system’s outermost surface. Emissivity is the relative effectiveness of a surface to emit and absorb heat by radiation. It is expressed as a ratio between 0 and 1 and is most relevant to the outermost jacketing to be used on an insulation system. The higher the emissivity, the more heat transfer will occur between the material and its environment via radiation. When considering chilled water pipes in warm environments, low emissivity jacketing materials—such as aluminum and steel—will absorb less heat from their surroundings via radiation, which will result in a lower jacketing surface temperature. Conversely, high emissivity jacketing materials—such as PVC and ASJ—will absorb more heat from their surroundings, yielding an overall higher surface temperature for the same system and potentially preventing surface condensation from taking place.

These complications around moisture intrusion can vary in significance based on the geographic location of a project. In cooler and more arid regions, there may be less humidity present within the air to contribute toward a vapor drive into an insulation system. However, in warmer and more tropical environments, vapor drive tends to be a much more significant issue that requires forethought and design consideration. As a best practice, it is advised to consider the worst-case conditions for a given environment when conducting energy calculations to mitigate the risk that moisture intrusion may present for a below-ambient system.

Challenges with Hot Water and Steam Lines

Pipes that carry hot processes such as steam and hot water are not subject to vapor drives in the same way that chilled water lines are, but they have equally significant risks that can lead to system complications if not designed around. As we will discuss in later sections, there are other scenarios that can lead to unexpected moisture ingress into an insulation system. If liquid water were to penetrate a hot-water or low-pressure steam line, it could present an even greater risk for CUI to occur than with pipes operating at chilled water temperatures. This is because electrochemical processes, like the formation of rust, occur more rapidly at higher temperatures. This means that if moisture penetrates an insulation system and contacts the surface of a steel pipe, and the pipe is operating at a low enough temperature for water to remain in liquid form (as with hot-water and low-temperature steam lines), then corrosion can emerge as a significant threat to the longevity of the piping itself.

In the case of high-pressure steam lines, piping is often operating at a temperature that is too hot for water to remain in liquid form to come into contact with it. In some regards, this alleviates the potential for corrosion to occur, as liquid water is a key ingredient for corrosion to take place. However, if a large amount of moisture were to penetrate such a system while not in operation, it could lead to other, more immediate issues. In this case, if insulation were to become saturated with water when the system is out of service, and the system is then quickly brought up to operating temperatures over 400°F (204°C), the heat generated could rapidly convert the water in the insulation to high-pressure steam, potentially destroying the insulation system as the steam is violently driven away from the hot pipe. This places increased emphasis on the performance of the moisture or vapor barrier to mitigate the risk of moisture penetration into a system.

One more consideration for high-temperature lines is the potential expansion that a stretch of piping will experience while in operation. Steel, like most other materials, will expand in size as it increases in temperature. For a hypothetical 100-foot run of carbon steel pipe on a steam line that increases from 70°F (21°C) to 400°F (204°C), the run of piping may experience an increase in length of about 2.6 inches. Underground expansion loops, or zees, are often installed in piping systems as locations intentionally designed to bend and allow this expansion to occur without putting stress on or damaging the piping itself. It is important that whatever insulation system is installed, it is designed in a manner to allow for this movement to occur at these critical locations, otherwise they become prime locations for damage to the vapor/moisture barrier to occur.

Challenges with Vaults and Tunnels

The piping networks that make up district energy systems typically travel from energy supplier to building users through an underground network. In many cases, this is via underground enclosed spaces, such as vaults and tunnels, which present additional challenges to insulation systems on pipes within them.

Depending on the size of an underground tunnel, it could be periodically accessible to maintenance activities that expose the insulation system to unanticipated foot traffic. It also is not uncommon for vermin to find their way into these tunnels and burrow into any materials they can. These points, while easy to overlook, place an importance on insulation materials to be durable enough to withstand such possible sources of damage.

Another unplanned-for event that often impacts tunnels and vaults is flooding. While tunnels are not typically designed to allow groundwater into them, the reality is that over the life of an underground system it becomes increasingly common for flooding to occur within these underground spaces at some point. This presents a much more direct source of water intrusion, which can lead to exacerbated complications along the same lines as the ones discussed around vapor drive for chilled water lines, or moisture ingress for hot-water and steam lines.

Challenges with Direct Burial Lines

Alternatively to vaults and tunnels, it is common for district energy piping systems to be buried directly within ground soil. This can bring about separate environmental challenges to be considered.

One example involves the compressive forces associated with soil loads and live loads. Soil load refers to the weight exerted on a pipe from the above-soil backfill when a pipe is buried. It increases with soil density and burial depth. Live load refers to the weight transferred indirectly to piping from heavy or moving objects that may be present on the surface of the ground itself. Soil load will increase with the relative mass and movement of objects in question, as well as be greater for pipes of larger outer diameter or shallower burial depth. For piping systems traversing underneath roadways, this becomes a critical design element, as the added weight and movement from vehicles presents a significant source of forces that should not be overlooked. It is important to consider both the soil and live loads that a direct burial system may be subject to and choose an insulation material with the compressive strength needed to resist them.

Another factor to consider for direct burial lines is the hydrostatic pressure the system may experience from groundwater. Hydrostatic pressure refers to the pressure that is exerted at a given point within a fluid due to the force of gravity. This challenge is most significant in locations of high water tables and heavy seasonal precipitation. If moisture is present in the soil, the water pressure will increase as a function of soil depth. If a permeable insulation is present and contains weak or poorly installed joints in its moisture/vapor barrier, this water pressure has the potential to drive moisture into underground insulation systems, where it can lead to future complications.

Considerations around Insulation Systems

It should be clear by now that district energy piping systems face multiple challenges that can affect their long-term performance. The insulation systems on these pipes should be designed with these challenges in mind to achieve the best and longest lasting performance possible. An important first step in designing a successful insulation system can take place during material selection. If a pipe will be subject to significant soil loading or foot traffic, consider choosing an insulation material that has the compressive strength to withstand the weight load it will be subject to.

Insulation materials with a zero or near-zero permeability rating can provide added protection against vapor drive that may be present in an ambient environment. Likewise, nonabsorbent insulation materials can resist retaining and becoming saturated from sources of water present. In either case, the total performance of the vapor/moisture barrier of a system is an integral part of the system’s longevity, so it is important to ensure appropriate and compatible accessory materials are used for the system in question.

Of course, even the best-designed insulation system will only perform as well as it is installed. This is why it is critical to ensure best practices for application of materials are being followed in the field through the utilization of available training courses and a robust inspection program.

Through proper engineering design, sound insulation material selection, and optimal installation techniques, district energy insulation systems can be relied upon to deliver reliable and efficient energy to our modern world.