Category Archives: Global

NIA Sites > Insulation Outlook Magazine > Global

Energy, Insulation, and Maintenance: Perfect Together

In an increasingly competitive global marketplace, few things remain constant. Business leaders who recognize this succeed by adapting quickly to market forces to gain the competitive advantage in their industries. During the more than 40 years former chief executive officer (CEO) Jack Welch spent at General Electric (GE), he focused on reducing inefficiency to gain the competitive advantage. This management strategy has been embraced by many modern-era executives. However, accomplishing that competitive edge may take a wide variety of different approaches by today’s plant managers. Some might subscribe to the “slash and burn” approach to make this quarter’s financials appear strong. Forward-thinking managers might seek out more strategic, long-term answers.

Large companies, as well as individual facilities within strong, successful companies, are all faced with unique challenges. The different management styles employed are usually quite apparent. Often, the focus—or lack thereof—is evident at the main gate. The outward appearance of a large manufacturing plant sends a loud message to visitors, employees, and the entire community about just how committed its management is to safeguarding the stakeholders’ value.

A refinery manager once lectured his entire staff after a serious incident had occurred in the facility. “We should all consider it a privilege that the neighbors permit us to operate in their backyard, and we should do everything in our power to safeguard that privilege,” he said.

The roles of the plant maintenance engineer, operations engineer, and facility energy coordinator are all critical. But often the goals of the maintenance, operations, and engineering groups are not in lock-step with one another because the demands on each group are always changing. The utilities engineer, energy coordinator, and operations supervisor know what the real opportunity cost of not maintaining the equipment in a safe, reliable, and energy-efficient condition would be. These positions greatly influence the bottom-line performance of a profitable plant. Reduced process unit throughput due to boiler or steam-system unreliability directly affects the performance of the entire plant. Facilities’ Energy Intensity performance accounts for 50 to 55 percent of the annual operating expenditures in a typical 160,000-barrel-per-day (b/d) refinery.

Every 2 years, the refining industry receives performance data from the latest Solomon Associates’ study. Year after year the data show that, to succeed, an energy management program must be built on a base of solid maintenance practices, and realistic reliability and inspection details. How the various groups work to achieve overall first or second quartile Solomon performance in the areas of energy and maintenance differs from company to company, and also from plant to plant within a specific company. Sound maintenances practices include a “plan, do, check, act” dictum and focus the facility on sustained improvement.

Periodic process-unit assessments play a key role in this program. That approach must become part of the culture to ensure results. The ideal maintenance plan is integrated with the energy goal of the facility; it does not include a “find, fix, and move on to the next emergency” way of thinking. Several plants have actually seen their annual Environmental Integrity Index (EII) scores diminish as a result of aggressive energy programs that featured a significant emphasis on insulation and refractory system improvements. The Sunoco refineries in the northeast United States typically demonstrate plant EIIs in the low 80s, which equates to 80 percent of the allotted “standard energy” consumption permitted. That is pacesetter-level performance.

Sunoco has a well-supported and quite mature insulation program. Since 1999, when the company began doing unit insulation assessments, Sunoco has allocated more than $6 million in its capital energy and operational expenditure (OPEX) budgets to address insulation system deficiencies. That level of spending does not go unnoticed at individual plants. Senior management has come to expect the 80-percent-plus return on investment (ROI) that a typical insulation upgrade project returns.

“Take care of the steel, and it will take care of you” is an old saying many workers trust. This also applies to the insulation and refractory that protects pipe and boiler casings from premature failure. Sam Schell, a boiler specialist and president of Sesco, Inc., says there are three “goods” that come from proper insulation:

  • It is “good” for saving British thermal units (Btus) and dollars.
  • It is “good” for the environment (lower emissions).
  • It is “good” for the plant’s bottom line (profitability).

Maintaining a facility’s infrastructure and achieving a pacesetter-level energy program go hand in hand.

Too often, maintenance and energy-efficiency goals are not aligned and are even offsetting. The article “Whose Line Is it Anyway?” from the December 2005 issue of Insulation Outlook should be required reading for plant managers and facilities engineers. In it, an example of a rubber plant illustrates much of what is deficient in major industrial facilities. The correlations drawn in the article work for just about any type of manufacturing plant.

The ever-increasing energy prices in recent months have been hard to ignore. It is impossible to predict whether oil will ever return to the $25-per-barrel (bbl) level, or whether natural gas will drop below $6 per decatherm (Dth). American industrial concerns are truly being put to a test. They can no longer wait until the government arrives to bail them out of a tight jam.

Each industry must adopt a sound energy program specific to its needs. It would be wise for large industrial process plants to focus on the following factors:

  • Achieving optimal combustion efficiency in heaters and boilers
  • Maximizing process–to–process and process–to–boiler feed water (BFW) heat transfer
  • Minimizing steam and condensate losses, and venting
  • Eliminating flaring of process gases
  • Installing and maintaining improved process-control systems
  • Maintaining and upgrading insulation and refractory systems
  • Monitoring, measuring, and maintaining equipment
  • Targeting a 3- to 5-percent annual energy reduction goal and striving to achieve that goal
  • Researching new technologies
  • Spreading the excitement of meeting set goals to all involved, including employees, neighbors, contractors, vendors, consultants, and stockholders

These goals may seem like pie in the sky to many plant supervisors, but they are not. Solomon Associates advises the entire refining industry of what is required to achieve pacesetter-level performance, and each of these areas of focus is within reach for many plants. It does take education and commitment from the whole plant community, including the maintenance area. It also requires a “champion” of sorts to carry the banner forward, especially when money is scarce or other resources are few. Many companies have such a champion, but many more lack that level of commitment. In the National Insulation Association’s (NIA’s) National Insulation Training Program (NITP), it is emphasized that keeping the message clear and concise to management and all of the plant population is the task of a program champion.

Insulation may not get the respect it deserves, but it is a simple, cost-effective way to save energy and money. Plant engineers and other facility managers can start by performing a small, focused insulation assessment. There is a good case to be made for installing or maintaining insulation systems at industrial facilities.

Figure 1
Figure 2
NIA Sites > Insulation Outlook Magazine > Global

A Growing Concern: Insulation’s Value to the Citrus Industry

Insulation is a powerful resource when designed, applied, and maintained properly; yet the technology is often forgotten or ignored. The National Insulation Association (NIA) recently conducted a survey of more than 160 industrial plants and manufacturing, engineering, and architectural firms. The survey found the following:

  • Most had no idea of the payback period or rate of return for using insulation, and they did not know of a method for quantifying costs versus savings.
  • Many acknowledged that numerous areas of insulation were in serious need of repair.
  • The majority did not understand that insulation has a real environmental “tie-in.”
  • Some did not consider additional insulation “necessary” (they felt their plants were working fine).
  • Many could not relate corrosion under insulation (CUI) to insulation.
  • Most acknowledged their specifications were outdated.
  • Many confirmed that they did not have a dedicated job function that addressed insulation specifications, or anyone on staff who was considered the “insulation champion.”
  • Many did not think of insulation as a “system” that requires any special design review or technical consideration.

The survey confirmed that insulation gets little respect, and it formed the basis for a major industry education and awareness initiative.

Focusing on Benefits

In many cases, the benefits of insulation are invisible, but long-lasting. The technology itself is not mysterious. It may be misunderstood and underappreciated due to lack of knowledge, but calculating its operational benefits and return on investment (ROI) can be relatively simple.

An insulation system does not have moving parts, bells and whistles, computer chips, or fancy gauges—and it is certainly not “sexy”—but it is a time-tested and proven technology that often can provide an annual ROI of more than 100 percent. It may be that insulation is often overlooked, undervalued, and forgotten precisely because its principles are simple and not necessarily revolutionary. Now is the perfect time to start thinking about this valued technology differently.

The citrus industry is a good place to start. This article will look specifically at mechanical insulation systems—those used for piping, equipment, vessels, ducts, boilers, and other similar mechanical equipment and piping applications.

Energy Conservation

Energy is one of the most costly components in managing a manufacturing facility and its processes. Reducing energy consumption reduces cost—a constant objective for most companies and within the citrus industry. If not at the top of the list, it is certainly one of the top ten corporate initiatives, along with safety, quality, shareholder value, and the environment.

Energy is required for both sides of the temperature spectrum. It takes energy to air condition space and/or chill or freeze products, yet energy conservation often is only discussed for applications involving heat. That should not be true for the citrus industry, however.

Insulation can be one of the easiest, fastest, and least costly technologies for reducing energy costs, but quite often it is the last option considered. Some insulation systems were designed for the cost of energy in 1977, rather than in 2007. The ROI with an insulation initiative usually exceeds expectations. Many times the return is realized in less than 1 year, meaning insulation can provide a faster return than many of the fancier and more visible energy-efficiency investments.

It is interesting to review the process for determining the design criteria for insulation on new construction or expansion projects versus the maintenance process, and how priorities are established. In new construction, the primary driver in determining the insulation system is the process. Very seldom are the insulation system and thicknesses examined from an energy conservation perspective. Once the plant is operating, plant management is unlikely to compare actual results to original expectations.

What do plants lose by not maintaining insulation systems in a timely and correct manner? It has been estimated that between 20 and 30 percent of all installed mechanical insulation is either damaged or missing. The citrus industry’s numbers were within or even above that range.

Recently, a heat-loss analysis was completed on the “typical” insulated piping systems within an oil refinery. The analysis illustrated the difference between the worst-case scenario (uninsulated piping), what could be obtained if all piping were insulated, and the case of reality where 21 percent of the pipe insulation was damaged or missing (see Figure 1). Since this analysis was completed, it has been compared to other industry segments—both for hot and cold applications—and determined to be a representative illustration. With 21 percent of the pipe insulation missing or damaged, only 52 percent of the potential heat-loss savings in British thermal units per hour (Btus/hr) was obtained. This is a big number, even if you discount it by 50 percent. Why does this condition exist when it can be corrected to provide a significant return on the capital employed for maintenance?

The typical oil refinery example showed 400,000 lineal feet of piping missing or with damaged insulation, which in turn equated to 5,800 barrels of oil lost per day. At $55 per barrel, that is $319,000 lost per day. These are huge numbers in any industry!

Other examples can be seen in the findings of the Save Energy Now (SEN) program, part of the Department of Energy’s (DOE’s) Industrial Technologies Program (ITP). SEN is part of a national campaign by the DOE to help manufacturing facilities reduce energy and operating costs, and operate more efficiently and profitably. Independent specialists trained to use sophisticated software assessment tools and who have passed a rigorous qualifying exam visit plants and identify immediate and long-term opportunities for improving energy efficiency and bottom-line results. Mechanical insulation is one of the many opportunities examined. (To learn more about the SEN program and see the outcome of one such energy assessment, please visit www.insulation.org/articles/article.cfm?id=IO070703.)

Here are a few mechanical insulation statistics derived from the SEN energy assessments:

  • 51 percent of the reports specifically mentioned insulation.
  • 63 percent of the insulation opportunities referred to “missing, damaged, or uninsulated areas,” while 37 percent referred to insulation upgrade or improvement opportunities.

Of the insulation references in the reports:

  • 81.5 percent were classified as near-term opportunities.
  • 14.8 percent were classified as medium-term opportunities.
  • 3.7 percent were classified as long-term opportunities.

Savings from insulation were, in many cases, identified in dollar terms—some approaching $1 million per year. Other ROI opportunities could be realized in fewer than 4 months.

The specific mechanical insulation tool that was used by the SEN program assessment specialists was the 3E Plus® Insulation Thickness Computer Program from the North American Insulation Manufacturers Association (NAIMA). Figures 2 and 3 provide two examples of information obtained using the program.

Energy conservation, with the use of properly designed, installed, and maintained mechanical insulation in the citrus industry—for a hot or cold application—is an opportunity that should not be overlooked. It is an investment that may have few rivals from a return perspective.

Figure 4 provides a graphic overview of the cost of energy compared to the cost of insulation and to the total cost.

Process Control

For process control, mechanical insulation is typically “engineered” into the process. Whether dealing with a fluid, air, or gas, the goal is to leave Point A at one temperature or pressure and arrive at Point B at another, or to be stored at a given temperature. Fluctuating temperatures can cause significant problems in manufacturing quality and productivity, so insulation is a major component of the equipment and manufacturing design process. However, designers do not always understand the various insulation systems available, the mechanics required to determine the correct insulation system, or material properties for specific application. Often, the insulation system or thermal value is determined by what worked in the past. In the industry, this is referred to as “dusting off the old specification.” Unfortunately, the reality is that insulation systems are rarely engineered.

Recently, the wrong old specification was pulled from the shelf and a hot insulation system was specified for a −100°F application. This is a disaster waiting to happen—a perfect opportunity for others to take advantage of the wrong specification in the bidding process.

The knowledge base of mechanical insulation systems at the engineering, architectural, and facility-owner level over the last 15 to 20 years has decreased. This is a by-product of the corporate world’s drive for profits, as well as right-sizing and multitasking objectives. The insulation field is not attracting specialization in the engineering, architectural, or maintenance arenas. This reduced knowledge base has led to the under-utilization or improper use of mechanical insulation in many applications.

With process design, selecting the right insulation system and determining the correct insulation thicknesses and values for the design conditions can be critical to the manufacturing process. This is especially true in the citrus industry, which requires design criteria that will:

  • protect against bacteria development;
  • address work areas that are subject to continual washdown;
  • insulate piping and equipment subject to dual operating purposes;
  • prepare for internal and external inspections, such as those performed by the Food and Drug Administration (FDA); and
  • provide freeze protection.

Figure 5 shows one of the design graphics or “plates” from the Midwest Insulation Contractors Association (MICA). This is an integral part of the insulation design guide contained in MICA’s National Commercial & Industrial Standards Manual.

One problem in the citrus industry (and others) is that insulation systems that have been designed, selected, and installed are not being maintained in a timely and proper manner. With improperly maintained insulation, process temperatures and pressures take more energy to maintain. This can affect throughput and costs. A simple but effective example of this is the air-conditioning system in a house or office: If the duct insulation is damaged or missing, the air-conditioning equipment cannot perform as designed.

Process control, quality, and product throughput are major considerations in the citrus industry. Properly designing, installing, and maintaining mechanical insulation systems should be an integral part of both the initial design and operational maintenance management plans.

Condensation Control and Mold Prevention

Moisture is an enemy. If an insulation system is not properly designed to maintain the surface temperature above the dew point, condensation will develop. This is a real-world problem that—if not corrected—can lead to other problems. Examples of this include work hazards, due to moisture on the floor, and the development of mold.

Mold is a serious problem in the work environment. Insulation cannot stop mold from developing. However, it certainly helps eliminate moisture due to condensation, which must be present for mold to develop. Prevention is less costly than cure. If the insulation system is not designed, installed, and maintained correctly to prevent condensation under realistic adverse conditions, condensation can occur. This problem should be addressed in an aggressive, timely manner.

Figure 6 is an example of mold growth on a cold piping system in an uncontrolled utility space.

Moisture Intrusion and Corrosion Under Insulation (CUI)

Moisture intrusion in an insulation system can lead to many problems. By spending some money early on, in a managed approach, one can avoid spending a lot of money later in a reactionary mode.

How does moisture penetrate an insulation system? The primary moisture sources are rainwater, water from a washdown, piping leaks, and water from condensation within the insulation system (especially on dual operating systems). The most likely areas of intrusion are at penetration points, such as gauges or attachments (see Figure 7). If either the integrity or exterior of the insulation system is not installed and maintained correctly, moisture will more than likely penetrate the system. The rate of moisture migration and/or wicking varies depending on the insulation system, the temperature of the operating system, and other conditions.

Moisture intrusion can negatively affect all aspects of the insulation system. Thermal values can have a direct impact on process control, energy cost, condensation control, safety, and the potential of mold development—not to mention the potential for CUI.

CUI is not new, and in many circles it is well understood; yet it costs industry millions of dollars annually. Unfortunately, the citrus industry is included in those statistics. It is generally accepted that carbon steel operating between 25°F and 300°F is at the greatest risk. Corrosion occurs at those points of water entry into the insulation where the temperature is below 300°F, and the piping and equipment are idle. Stress cracking of stainless steel under insulation is primarily manifested by a combination of water and external sources of chlorides. Carbon and stainless steel corrode because moisture is present. Insulation can provide an annular space or crevice for water retention with full access to oxygen and other corrosive media. Insulation material may wick or absorb moisture, and increase or accelerate the corrosion rate. With the right conditions, CUI is possible under all types of insulation.

If insulation does not directly cause corrosion, could maintaining the integrity of the insulation system minimize CUI and save money in the long term? To answer that question, life-cycle cost analysis should be employed. Without question, removing an insulation system, replacing piping and equipment, and installing a new insulation system is an expensive process. It is possible that an aggressive maintenance program, combined with regular inspections, could be less costly over time.

Reduction of Greenhouse Gas Emissions

Reducing energy consumption by properly using and maintaining mechanical insulation can reduce greenhouse gas emissions currently being released into the atmosphere.

A 1998 study of mechanical and building insulation in commercial buildings, excluding roofing, found that insulation saved 211 billion pounds of carbon dioxide (C02) from being emitted into the atmosphere each year. This benefit is not considered in many applications, but what if it was included in ROI calculations or used in the decision-making processes for a plant? Answers will vary depending on the facility, carbon credits (if applicable), and regulatory requirements. However, the public relations benefit cannot be ignored. Besides, it is the right thing to do.

Personnel Protection

Protecting workers from coming in contact with hot or cold surfaces, and from excessive equipment and other workplace noise, should be a focus of any safety program; yet insulation is seldom, if ever, on the agenda for safety meetings.

The standard is that a surface temperature above 140°F should be insulated for personnel protection, but is this practical and effective? Lowering a company’s experience modification rate (EMR) is a primary objective safety programs. The lower the EMR, the lower the insurance costs. Insulation may not be able to lower the EMR, but it can be an integral part of an accident-prevention program.

The role of mechanical insulation in providing a safe work environment is seldom considered. Far beyond the impact on a company’s bottom line is the direct impact on the well-being of its employees. Can you think of a more important topic or a better reason to think about insulation differently?

Improving the Workplace

Insulation is a major component in improving facility occupant comfort and thus increasing productivity. Many studies confirm that occupant productivity increases when indoor air quality, temperature, and sound are managed within an acceptable range on a consistent basis. Insulation’s thermal and noise-absorption properties thus can provide a real ROI in the workplace.

Sustainable Design Technology

Sustainable design is used more every year. Mechanical insulation’s role is normally included in discussions related to heating, air conditioning, or other equipment. In some cases, the size of the equipment required has been reduced due to the use of increased insulation values. Capital investment is reduced, and the return is increased. That is a winning combination.

Many companies are pursuing sustainable design certification for buildings and plants. This is an effective way to measure success in sustainability. However, thinking green and employing that philosophy are just as important, if not more so, than attaining certification. Thinking, promoting, and selling green can be an advantage within an organization, with customers, and certainly within the larger community.

Insulation: A Powerful Technology

The most obvious benefits of insulation are energy conservation and process control. While those are at the top of the list, there are other important advantages to properly using and maintaining insulation. The combined results make insulation a powerful technology. The need and value of a properly designed, installed, and maintained insulation system is more important today than it ever has been. There are educational programs, software tools, and human resources available that can help explore the many benefits that mechanical insulation can provide. Increased knowledge of mechanical insulation can provide, in many cases, an unrivaled ROI opportunity in the new construction and maintenance arenas. It also can help to reduce our dependency on foreign energy sources, protect our environment, and improve our economy.

The citrus industry is a major user of mechanical insulation, yet it is also a prime example of an industry that has not used mechanical insulation to its full potential. By thinking differently about mechanical insulation and the value it can provide, insulation end users in various industries can take advantage of the power of insulation.

REFERENCES
American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.—2005 ASHRAE Handbook, Fundamentals I-P Edition, Chapter 26, Insulation for Mechanical Systems • Midwest Insulation Contractors Association—National Commercial & Industrial Insulation Standards, 1999 Fifth Edition • North American Insulation Manufacturers Association—3E Plus® Insulation Thickness Computer Program, Pub. C12128/05 and Software Program • National Insulation Association—Insulation Outlook, November 2006, “CUI: An In-Depth Analysis” • National Insulation Association—National Insulation Training Program (NITP) • National Insulation Association—“The Power of Insulation” and “Insulation: The Lost or Forgotten Technology” presentations • The U.S. Department of Energy (DOE)—Industrial Technologies Program (ITP), Save Energy Now (SEN), Partner Results

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
NIA Sites > Insulation Outlook Magazine > Global

Making Mold a Problem of the Past

Molds can be found almost anywhere; they can grow on virtually any organic substance, as long as moisture and oxygen are present. There are molds that can grow on wood, paper, carpet, foods, and insulation. When excessive moisture accumulates in buildings or on building materials, mold growth will often occur, particularly if the moisture problem remains undiscovered or unaddressed. It is impossible to eliminate all mold and mold spores in the indoor environment. However, mold growth can be controlled indoors by controlling moisture indoors.

Concern about indoor exposure to mold has been increasing as the public becomes aware that exposure to mold can cause a variety of health effects and symptoms, including allergic reactions. This article presents guidelines for the remediation and cleanup of mold and moisture problems in schools and commercial buildings.

Key Steps for Mold Remediation
  • Consult a health professional as appropriate throughout the process.
  • Select a remediation manager.
  • Select a team of remediation personnel.
  • Choose between outside or in-house expertise.
  • Assess the size of the mold problem and note the type of mold-damaged materials.
  • Communicate with building occupants throughout the process, as appropriate to the situation.
  • Identify the source or cause of the water or moisture problem.
  • Plan remediation and adapt available guidelines to fit the situation (see Figures 1 and 2).
  • Select personal protective equipment (PPE).
  • Select containment equipment.
  • Remediate.
  • Fix the water or moisture problem.
  • Clean and dry moldy materials (see Figure 2).
  • Discard moldy items that can’t be cleaned.
  • Dry non-moldy items within 48 hours (see Figure 1).
  • Check for the return of moisture and/or the mold problem.
  • If hidden mold is discovered, reevaluate the plan.
Laying the Groundwork

It is important to start by developing a remediation plan. Assess the size of the mold and/or moisture problem and the type of damaged materials before planning the remediation work. Select a remediation manager for medium or large jobs (or small jobs requiring more than one person). The remediation plan should include steps to fix the water or moisture problem, or the problem may reoccur. The plan should cover the use of appropriate personal protective equipment (PPE), and should include steps to carefully contain and remove moldy building materials to avoid spreading the mold. A remediation plan may vary greatly depending on the size and complexity of the job, and it may require revision if circumstances change or new facts are discovered.

The remediation manager’s highest priority must be to protect the health and safety of the building occupants and remediators. It is also important to communicate with building occupants when mold problems are identified. In some cases, especially those involving large areas of contamination, the remediation plan may include temporary relocation of some or all of the building occupants.

When making the decision to relocate occupants, one should consider the size and type of the area affected by mold growth, the type and extent of health effects reported by the occupants, the potential health risks that could be associated with debris, and the amount of disruption likely to be caused by remediation activities. If possible, remediation activities should be scheduled during off-hours when building occupants are less likely to be affected.

Remediators, particularly those with health-related concerns, may wish to check with their doctors or health-care professionals before working on mold remediation or investigating potentially moldy areas.

HVAC Systems and Mold

Do not run the heating, ventilation, and air-conditioning (HVAC) system if you know or suspect that it is contaminated with mold. If you suspect that it may be contaminated (for example, if it is part of an identified moisture problem or there is mold growth near the intake to the system), consult the EPA’s guide at www.epa.gov/iaq/pubs/airduct.html before taking further action.

Hidden Mold

In some cases, indoor mold growth may not be obvious. It is possible that mold may be growing on hidden surfaces, such as the back side of dry wall, wallpaper, or paneling; the top of ceiling tiles; or the underside of carpets and pads. Possible locations of hidden mold can include pipe chases and utility tunnels (with leaking or condensing pipes), walls behind furniture (where condensation forms), condensate drain pans inside air-handling units, porous thermal or acoustic liners inside ductwork, or roof materials above ceiling tiles (due to roof leaks or insufficient insulation).

Some building materials—such as dry wall with vinyl wallpaper over it or wood paneling—may act as vapor barriers, trapping moisture underneath their surfaces and thereby providing a moist environment where mold can grow. You may suspect hidden mold if a building smells moldy but you cannot see the source, or if you know there has been water damage and building occupants are reporting health problems. Investigating hidden mold problems may be difficult and will require caution when the investigation involves disturbing potential sites of mold growth; make sure to use PPE. For example, removal of wallpaper can lead to a massive release of spores from mold growing on the underside of the paper. If you believe that you may have a hidden mold problem, you may want to consider hiring an experienced professional. If you discover hidden mold, you should revise your remediation plan to account for the total area affected by mold growth.

Reaching Remediation

The following are the most critical steps to mold remediation:

  • Fix the water or humidity problem. Complete and carry out a plan for repairs if it is appropriate. Revise and/or carry out a maintenance plan if necessary. Revise the remediation plan as necessary, if more damage is discovered during remediation.
  • Communicate. Continue to discuss progress with building occupants, as appropriate to the situation. Be sure to address all concerns.
  • Clean up mold and dry water-damaged areas completely. Select appropriate cleaning and drying methods for damaged and contaminated materials. Carefully contain and remove moldy building materials. Use appropriate PPE, and arrange for outside professional support if necessary.

Figure 1 offers strategies for responding to water damage within 24 to 48 hours. These guidelines are designed to help avoid the need for remediation of mold growth by taking quick action before growth starts. Depending on the size of the area involved and resources available, professional assistance may be needed to dry an area quickly and thoroughly.

Figure 2 presents remediation guidelines for building materials that have or are likely to have mold growth. The guidelines in Figure 2 are designed to protect the health of the building’s occupants and cleanup personnel during remediation. These guidelines are based on the area and type of material affected by water damage and/or mold growth. Please note that these are guidelines; some professionals may prefer other cleaning methods.

Although the level of personal protection suggested in these guidelines is based on the total surface area contaminated and the potential for remediator and/or occupant exposure, professional judgment should always play a part in remediation decisions. When in doubt, caution is always advised. Consult an experienced mold remediator for more information. In cases in which a particularly toxic mold species has been identified or is suspected, when extensive hidden mold is expected (such as behind vinyl wallpaper or in the HVAC system), when the chances of the mold becoming airborne are estimated to be high, or when sensitive individuals (such as those with severe allergies or asthma) are present, a more cautious or conservative approach to remediation is indicated. Always make sure to protect remediators and building occupants from exposure to mold.

Cleanup Methods

The following mold cleanup methods are available for remediating damage to building materials and furnishings caused by moisture-control problems and mold growth:

  • Use a wet vacuum. Wet vacuums are vacuum cleaners designed to collect water. They can be used to remove water from floors, carpets, and hard surfaces where water has accumulated. They should not be used to vacuum porous materials, such as gypsum board. They should be used only when materials are still wet; wet vacuums may spread spores if sufficient liquid is not present. The tanks, hoses, and attachments of these vacuums should be thoroughly cleaned and dried after use, because mold and mold spores may stick to the surfaces.
  • Remove mold with a damp wipe. Mold can generally be removed from nonporous (hard) surfaces by wiping or scrubbing with water, or with water and detergent. It is important to dry these surfaces quickly and thoroughly to discourage any further mold growth. Instructions for cleaning surfaces, as listed on product labels, should always be read and followed. Any porous materials that are wet and have mold already growing on them may have to be discarded.
  • Vacuum with a HEPA vacuum. High-Efficiency Particulate Air (HEPA) vacuums are recommended for final cleanup of remediation areas, after materials have been thoroughly dried and contaminated materials removed. HEPA vacuums are also recommended for cleanup of dust that may have settled on surfaces outside the remediation area. Care must be taken to assure that the filter is properly seated in the vacuum so that all the air must pass through the filter. When changing the vacuum filter, remediators should wear PPE to prevent exposure to the mold that has been captured. The filter and contents of the HEPA vacuum must be disposed of in well-sealed plastic bags.
  • Remove damaged materials and seal in plastic bags. Any building materials and furnishings that are contaminated with mold growth and are not salvageable should be double-bagged using 6-mil polyethylene sheeting. These materials can usually be discarded as ordinary construction waste. It is important to package mold-contaminated materials in sealed bags before removing them from the containment area to minimize the dispersion of mold spores throughout the building. Large items that have heavy mold growth on them should be covered with polyethylene sheeting and then sealed with duct tape before they are completely removed from the containment area.
Containment Tips

The purpose of containment during mold remediation activities is to limit the release of mold and other toxins into the air and surroundings, minimizing the exposure of remediators and occupants to mold. The following tips will help keep mold and moldy debris from spreading to areas beyond the contaminated site:

  • Maintain the containment area under negative pressure.
  • Use exhaust fans to the outdoors and ensure that adequate makeup air is provided.
  • Make sure the polyethylene sheeting billows inward on all surfaces when containment is working. If it flutters or billows outward, containment has been lost, and you should find and correct the problem before continuing.
How To Know Remediation and Cleanup Are Finished

Make sure each item on the following checklist is complete to ensure that the remediation process is finished:

  • The water or moisture problem has been completely fixed.
  • Mold removal is complete. (Use professional judgment to determine if the cleanup is sufficient. Visible mold, mold damaged materials, and moldy odors should not be present.)
  • If sampling was used, the kinds and concentrations of mold and mold spores in the building should be similar to those found outside once cleanup activities have been done.
  • Shortly after remediation, a visit to the site(s) should reveal no signs of water damage or mold growth.
  • People should be able to occupy or re-occupy the building space without health complaints or physical symptoms.

This article has been reprinted with permission from the U.S. Environmental Protection Agency (EPA). For expanded information, please visit www.epa.gov/mold/mold_remediation.html.

Figure 1
Figure 2
NIA Sites > Insulation Outlook Magazine > Global

Insulation Recommendations for Manufacturing Facilities From An Industrial Assessment Center

The Industrial Assessment Center (IAC) at West Virginia University has been in existence with funded support from the U.S. Department of Energy (DOE) since 1992. Based on its assessments, insulation is a highly recommended opportunity for energy savings. In fact, per the IAC database, insulation is one of the top ten recommendations to industrial facilities. It is interesting to examine the insulation recommendations for manufacturing companies across various Standard Industrial Codes (SICs) with respect to corresponding energy and cost savings.

Instruments such as handheld infrared temperature measurement guns and digital thermal imaging equipment were used for these recommendations. In addition, the DOE’s recommended BestPractices software tool, as well as 3E Plus® and fundamental engineering principles were applied to estimate the energy and cost savings. Figure 1 shows the digital and thermal image of a boiler surface. The thermal image reveals that the center part of the boiler surface is extremely hot—with a temperature of more than 500°F—while most of the surface temperature is in the range of 250° to 300°F.

Most manufacturing facilities recognize the benefits of proper insulation on hot and cold surfaces and pipes, yet others neglect this important aspect. These facilities’ intense focus on fulfilling production targets leaves little time to investigate energy losses due to lack of insulation. The general description and the SICs for some of the manufacturing facilities visited by the IAC are shown in Figure 2.

The average amount of annual recommended energy savings among the manufacturing sector showcased in Figure 2 is shown in Figure 3.

Close to 64 percent of the total recommended energy savings from insulation projects was realized in terms of natural gas equipment surfaces and/or distribution lines, followed by sawdust systems (with 24-percent savings). Insulation of electrical systems contributed to 7 to 8 percent of the total recommended savings. Coal and other fuels together had less than 5 percent of the total savings. Based on this analysis, it is evident that natural gas systems (such as boiler surfaces and steam distribution lines) have high potential for effective insulation and should receive adequate attention for insulation projects.

Manufacturing facilities with SICs 3955, 3553, and 2436 had the highest energy-saving opportunities from insulation projects (see Figure 2). SIC 3955 is carbon paper and inked ribbons manufacturing, while SICs 3553 and 2436 are both related to wood-manufacturing industries. An analysis of the energy-saving recommendations reveals that the ones that were related to SIC 3955 involved insulating the coating machines. The uninsulated machine surfaces were losing significant heat energy. The amount of energy lost through the surfaces was close to 20 percent of the total energy used by the plant. After insulating the surface with proper material, the plant was able to reduce its energy cost by approximately $25,000 per year.

As an example, one of the vertical surfaces that needed insulation had a temperature of 260°F. The surrounding temperature was measured at 70°F, and the maximum allowed temperature was assumed to be 140°F. Since this was an indoor area, the wind speed was assumed to be 0 miles per hour (mph). Based on this information, 3E Plus software (see Figure 3) was used to estimate the amount of energy loss before and after the insulation.

Savings

As shown in Figure 4, after adding 1 inch of 450F M F BOARD ASTM C612-00a T1B insulation material, the heat loss reduced from 451.7 British thermal units per hour per square foot (Btus/hr/sf) to 45.5 Btus/hr/sf. Therefore, the total savings from insulating the surface is 273 million British thermal units (MMBtus) per year. Similar analysis was performed to quantify the recommended energy savings from insulating all of the surfaces identified.

One of the companies under SIC 3553 had recommendations related to insulation of steam distribution lines and dock doors. The total savings from the two insulation recommendations resulted in savings of approximately 8 percent of the total natural gas cost per year. Similar savings from insulation improvements were recommended for other companies. In most cases, the insulation recommendations were related to steam distribution lines, boiler surfaces, dock doors, and ovens. Energy-saving opportunities not only reduce a company’s operating cost, but also reduce the amount of carbon dioxide (CO2) emissions (approximately 113 pounds per MMBtu of natural gas usage reduction). This makes a company competitive and environmentally efficient at the same time.

The cost of implementing the recommendations also was considered and was estimated to result in an average simple payback period on investment of fewer than 6 months. In only a few facilities was the simple payback period on investment more than 1 year. Because of the low implementation cost, simple implementation procedures, and significant cost savings, the insulation recommendations have proven to be attractive for facilities to implement, resulting in an implementation rate close to 70 percent.

Figure 1
Figure 2
Figure 3
Figure 4
NIA Sites > Insulation Outlook Magazine > Global

How to Save Energy In Commercial Buildings: A Top 10 List

To commemorate Earth Day and bring awareness to the importance of energy conservation in commercial buildings, The Building Owners and Managers Association (BOMA) International released its top ten ways for building owners and managers to reduce energy consumption. These no- or low-cost strategies are part of the nationally recognized BOMA Energy Efficiency Program (BEEP) that offers commercial real estate professionals strategies for reducing energy consumption by as much as 30 percent.

“The built environment accounts for 48 percent of greenhouse gas emissions in this country,” says Kurt R. Padavano, RPA, CPM, FMA, SMA, BOMA International chairman, and chief elected officer and chief operating officer of Advance Realty Group of Bedminster, New Jersey. “The good news is that there are many low- and even no-cost strategies that are proven to save energy and reduce emissions, and they are easy to implement and often reduce building operation costs.”

“Saving energy is fundamental to all aspects of our lives,” adds Gary J. Bases, president of BRIL, Inc., author of The Bril Book (a complete guide on brick, refractory, insulation, and lagging systems), and American Society of Mechanical Engineers (ASME) instructor. “Thermal insulation is one of man’s first inventions and illustrates the need for energy conservation. Today’s conservation needs are increasingly important, and BOMA’s energy-efficient strategies address those needs.”

In addition to these ten areas, hot air ducts, ventilation, and cold air systems are vital components to all commercial buildings. How they are insulated depends on many factors and needs. Here are some examples:

  • Insulation with a factory-applied vapor barrier may be required to prevent the penetration water vapor and condensation from corroding the duct and fan system.
  • The thickness of the insulation and application requirements must be considered to prevent hot or cold air from leaving the system.
  • Insulation used as an absorbent filler can reduce tonal and broad band noise coming from the fans.

For more information, please visit www.boma.org.

BOMA Top 10 Energy-Efficient Strategies

1. Check that equipment is functioning as designed.

Regularly inspect all equipment and controls to ensure they are functioning as designed. Double-check Energy Management System (EMS) programming to make sure that operations are optimized. One firm changed an EMS software programming error from “and” to “or” and saved $3,700 annually. “You must remember that the equipment is the first place that raw energy is turned into useful work in the facility,” says Sam Schell, consulting engineer with SESCO, Inc. “A loose fan belt requires more energy to run the fan than a properly adjusted belt.”

2. Consider your cleaning options. The following cleaning options can be used to save the most energy for a particular commercial space:

  • Team cleaning: Janitors go through the building—floor by floor—as a team, and the lighting is turned on and off as they progress through the building.
  • Occupancy sensors: Motion sensors can be installed to automatically turn lights on when janitors are cleaning and turn them off when the floor is vacant.
  • Coordinated effort: Janitors can coordinate with the security crew to walk through the building and turn off equipment that was inadvertently left on by tenants.
  • Day cleaning: Why not have the janitors clean during the day while the lights are already on?

3. Encourage tenants to turn off equipment. During off-hours, make sure to power down everything, including copiers, kitchen equipment, and task lights. Use cleaning and security personnel to turn off miscellaneous items like coffee pots, kitchen equipment, and individual office lights.

4. Use high-efficiency light-emitting diode (LED) exit signs. Replace inefficient exit signs with high-efficiency LED exit signs. LED exit signs operate 24-7 and have lower maintenance costs due to their extended life.

5. Institute an energy awareness program. Create promotional items, posters, and news releases—tell everyone about your commitment to energy savings. Use your company newsletter, as well as company and building announcements, to keep tenants informed about your energy-savings goals, and how they can both help reach them and benefit from them.

6. Install monitor power-management software. In U.S. companies alone, more than $1 billion a year is wasted on electricity for computer monitors that are left on when they shouldn’t be. You can avoid those wastes by installing power-management software for computer monitors, central processing units (CPUs), and hard drives.

7. Change incandescent lights to compact fluorescent lights (CFLs) and high intensity discharge (HID) lights. CFLs use less energy, have a longer lamp life, and produce less heat, reducing heat load. Also, check the lighting in rest rooms, closets, server rooms, and common areas. Thanks to the 2005 Energy Bill, lighting retrofits and upgrades that meet energy-efficiency requirements may be tax deductible, up to 60 cents per square foot (psf).

8. Harvest daylight. Locate work stations that require high illumination adjacent to windows.

9. Evaluate after-hours usage. Talk to tenants to find out if they are actually using their spaces during the lease-required operating hours. Adjust building operating hours to reflect actual tenant usage.

10. Adjust ventilation. Reduce exhaust and outdoor-air ventilation rates within codes. Take a look at the fans, and adjust ventilation in unoccupied and low-density areas to reduce the ventilation to a practical, yet comfortable level.

NIA Sites > Insulation Outlook Magazine > Global

Commercial vs. Industrial Applications: Focus on Cold Applications

Insulation application types can be divided into many categories. One way to define them is by market: residential, commercial, or industrial. For the purposes of this article, the comparison will be limited to commercial versus industrial. How would a contractor approach these applications differently from a materials, quote, or labor standpoint? Focusing specifically on cold applications, this article will zero in on below-ambient-temperature applications.

How Are Commercial and Industrial Applications Defined?

First, what are some examples of commercial and industrial applications? Typical commercial applications include strip malls, office buildings, hospitals, schools, churches, hotels, condominiums, supermarkets, ice rinks, and maybe even light manufacturers. Common industrial applications include manufacturing, food processing or storage, chemical, petrochemical, and power plants. Contractors tend to classify themselves as either commercial or industrial based on the type of projects they work on most. Industrial contractors may bid on commercial work when the industrial sector slows down, but most commercial contractors stay predominately within their main area of expertise. Commercial work tends to track the economy and be fairly stable, while industrial projects tend to be based on longer-term economic projections and needs, and tend to be more cyclical (feast or famine). Once allocated, they progress regardless of current conditions.

The distinction between commercial and industrial contractors is fairly clear. However, as contracting firms become larger and their need for business grows, the distinction may blur.

Often, the perception of industrial applications is that they represent mostly “hot” insulation work. Although industrial applications may have more hot work (it is estimated that 75 percent of industrial work is hot), there are certainly plenty of industrial applications that involve cold water, chilled water, refrigeration, and cryogenic applications, too. From a temperature standpoint, industrial applications cover a wider range than commercial: Below-ambient industrial applications can go from 50° to -300°F or below, while commercial work stops around -10°F. With more extreme temperatures, industrial work often involves multilayer insulation because of the thickness requirements and additional vapor barriers needed to prevent condensation or ice formation. Industrial applications also may exhibit much greater temperature cycling, which can create issues with both the insulation and jacketing.

From a performance standpoint, industrial and commercial applications attempt to accomplish the same goals:

  • Reduce heat gain
  • Save energy
  • Reduce emissions
  • Prevent condensation
  • Improve equipment performance
  • Improve process performance
  • Reduce water consumption
  • Improve personnel protection
  • Control sound
  • Provide freeze protection

The thermal dynamics are the same for commercial and industrial applications.

Besides temperature range, other distinctions between commercial and industrial applications include the expectations or requirements for weather resistance, chemical resistance, corrosion resistance, pipe sizes, and longevity. Commercial jobs are probably new construction and predominately indoor applications, whereas industrial projects are often retrofit or plant expansion work, with an approximate outdoor-to-indoor ratio of 60-to-40. These factors tend to make industrial jobs much more complicated. Labor and jacketing selection are key factors as well. As Ray Stuckenschmidt of Systems Undercover, Inc., notes, “When you are dealing with industrial jobs, you have to really know what you are doing.”

Commercial jobs are easier to access, the work is not as congested, and there is less need for secondary jacketing, which allows the insulation to be applied more efficiently. On the other hand, commercial work often is released in stages as a job progresses. For example, condominium projects may be released as floors are finished, so the total time to complete the work may be much longer than that of an industrial job where the time frame is tighter because the job must be completed during a shutdown period. Some industrial jobs are bid on a time-and-materials or a cost-plus basis, which would not typically be the case on the commercial side. Industrial jobs must be bid with more contingency factors built in because of the variables that may be associated with the job. The safety record of a company is also very important when bidding for an industrial job, whereas that might not be a key component for a commercial job.

Unfortunately, many commercial jobs are submitted for bid with drawings that may be as little as 60-percent complete. “Commercial applications require a high degree of knowledge of the systems involved to ensure that the estimate is complete,” says W. Paul Stonebraker of TRA Thermatech.

Materials and Thickness Requirements

From a materials standpoint, the temperature range of commercial jobs means that the most common insulation products—such as fiberglass, polyolefin, or elastomeric materials—are usually used, although there is some overlap with the industrial jobs, which often use other materials, including cellular glass and polyisocyanurate. As changes in materials occur, they may be used in applications where they were not previously considered.

In some cases, the type of pipe material being covered may limit the type of insulation used. Minimum insulation thickness requirements will be dictated by building codes for commercial jobs, but by the building owner for industrial jobs. This means the contractor is more limited in materials for commercial jobs—there may be a couple of materials to choose from, depending on the engineering specification, but the minimum thickness will be dictated by code. Industrial owners often contact insulation contractors for input on what materials perform best. Whether the job is commercial or industrial, materials cost and ease of installation (labor) will dictate what is used. From the owner’s point of view, ease of maintenance also may be a factor in material selection.

Everyone looks for an edge that will provide a lower cost, which is where ease of installation can tip material selection one way or another.

In both industrial and commercial cases, application failure can result in major costs, so shortcuts should not be taken. Best practices must be employed. Because of project size, failures on industrial jobs may be larger, but owners are generally involved in the process and more specific about the type of insulation and installation. Since commercial work involves more contact with the public, the possibility of a lawsuit as a result of a failed job is more likely. The commercial contractor also has to be flexible and adapt to changing customer expectations that may not be as well defined as those in the industrial sector.

Consider, for example, the issue of mold and mildew. Paul Sawatzke of Enervation, Inc., points out that “the issue of moisture, mold, and mildew is changing the way many contractors are looking at the material selected for commercial jobs. We need to react to the needs of the marketplace.”

There may be the mistaken concept that commercial work can be taken less seriously than industrial work. One lawsuit will convince anyone that this is not the case. Being able to seal up the insulation system and keep moisture out is the key to a good below-ambient application.

Most building codes or insulation recommendations like ASHRAE 90.1 base their insulation thickness tables on energy savings. This is due to the complexity of the tables necessary to account for all of the variables that affect energy savings, condensation formation, and the liability associated with a recommendation if it results in a failed application. However, the thickness needed to prevent condensation is often greater than the reference tables suggest. Figure 1 can be used to compare materials with different K-values to determine the thickness needed to prevent condensation for a given set of conditions. The three K-values listed represent the range of general insulation materials available.

For higher relative humidity (RH), ambient temperatures, and pipe sizes—or for lower fluid temperatures—greater thickness will be needed to prevent condensation. In conditions where the dew-point temperature is close to the ambient temperature, the surface emissivity of the insulation jacket or facing can have a major impact on the insulation thickness required for condensation control. It is recommended that 3E Plus® or a program from the material manufacturer be used to calculate insulation thickness. In addition, some materials are only available in specific sizes. As shown in Table 1, the differences in K-value are not drastically different until the temperatures become more extreme. Greater insulation thickness also means greater jacketing and pipe hanger costs.

The insulation used on a job is only part of the cost. This is particularly true of outdoor applications that must be jacketed. Jacketing provides a variety of functions, such as weather protection (including protection from ultraviolet rays); moisture and moisture vapor protection; mechanical abuse resistance; chemical resistance; added corrosion resistance; and, in some applications, fire protection. Jacketing traditionally has been aluminum, stainless steel, or polyvinyl chloride (PVC). PVC is generally limited to commercial applications.

“Because of the often required multilayered insulation and jacket requirements, industrial jobs are more technical and require a very skilled work force. I would take industrial jobs over commercial jobs every day,” says Steve Isler of Old Dominion.

The Bottom Line

So how do commercial and industrial applications compare? Surprisingly, most contractors’ opinions on the topic are very consistent. First, it is evident that commercial contractors like to do commercial work and industrial contractors like to do industrial work. Each believes their sector of the business is the best in which to operate. Because of temperature extremes and environmental factors, industrial applications tend to be more complex, which limits the number of contractors bidding on such projects. For these applications, contractors seek out the materials and practices that provide the lowest cost and fastest installation, and give them an edge in quoting and providing reliable systems that meet the technical requirements of the job. This may be in the insulation itself, the jacketing, or the installation practices.

What does the future of commercial and industrial work look like? Peter J. Gauchel of L & C Insulation, Inc. says, “The commercial sector is strong right now. The industrial sector is also extremely strong and appears to be set to stay that way for some time in the future, based on the work in the power industry.”

Besides work in traditional power plants, ethanol plants are popping up all over the Midwest, and the prospect of LNG terminals from New York to Seattle should keep the industrial sector strong into the future. As for the commercial sector, as long as the economy stays strong, it will do just fine. Although the commercial and industrial sectors use similar materials and practices, and may have similar problems such as skilled labor shortages, the markets are distinctly different in how they are quoted, installed, and billed. Contractors in both sectors can be proud of their work—saving energy, reducing greenhouse gas emissions, and making the world run a little better, one pipe at a time.

Figure 1
Figure 2
NIA Sites > Insulation Outlook Magazine > Global

2030 Challenge: Acting Now To Reduce Global Greenhouse Gas Emissions

Proper use of insulation goes a long way toward saving energy, but those involved in the energy industry know that more efforts are needed to make a lasting impact. Reducing greenhouse gas emissions is one of the key steps to avoiding catastrophic climate change worldwide, yet there are hundreds of coal-fired power plants on the drawing boards in the United States. Seventy-six percent of the energy produced by these plants will be used to operate buildings. Architecture 2030—a non-profit, non-partisan, independent organization established in 2005 and sponsored by New Energy Economy—has shown that buildings are responsible for almost half (48 percent) of all the energy consumption and greenhouse gas emissions annually in the United States; globally, the percentage is even greater.

Stabilizing emissions in the building sector and reversing them to acceptable levels over the next 10 years will be critical. This will hold global warming to approximately a degree centigrade above today’s level. But how can this be accomplished? Architecture 2030 has issued The 2030 Challenge to the global architecture and building community to accomplish this impressive goal. The 2030 Challenge provides the following targets:

  • All new buildings, developments, and major renovations should be designed to meet a fossil-fuel, greenhouse gas–emitting, energy-consumption standard of 50 percent of the regional (or country’s) average for that building type.
  • At a minimum, an equal amount of existing building area should be renovated annually to meet a fossil-fuel, green house gas–emitting, energy-consumption performance standard of 50 percent of the regional (or country’s) average for that building type.
  • The fossil-fuel reduction standard for all new buildings should be increased in the following increments:
    • 60 percent in 2010
    • 70 percent in 2015
    • 80 percent in 2020
    • 90 percent in 2025
    • Carbon-neutral by 2030 (using no fossil-fuel, greenhouse gas–emitting energy to operate)

These targets may be accomplished by implementing innovative sustainable design strategies, generating on-site renewable power, and/or purchasing (20-percent maximum) renewable energy and/or certified renewable energy credits.

These targets are not out of reach. Most developments and buildings can be designed to use only a small amount of energy at little or no additional cost through insulation, proper planning, siting, building form, glass properties and location, material selection, and by incorporating natural heating, cooling, ventilation, and day-lighting strategies. The additional energy necessary to maintain comfort and operate equipment can be supplied by renewable resources, such as solar, wind, biomass, and other viable carbon-free sources.

To learn more about The 2030 Challenge, please visit www.architecture2030.org. Look for a more in-depth article on the challenge in the August issue of Insulation Outlook.

This article was reprinted with permission from Architecture 2030. Edward Mazria, American Institute of Architects (AIA), is a senior principal at Mazria, Inc., an architecture and planning firm in Santa Fe, New Mexico, and founder of Architecture 2030. He is author of The Passive Solar Energy Book, senior analyst for the Southwest Climate Council, and adjunct professor at the University of New Mexico. He speaks nationally and internationally on the subject of climate change and architecture.

NIA Sites > Insulation Outlook Magazine > Global

Understanding Pin Stud Failure in the Power Generating Industry

Studded tubes are found in many types of steam-generating boilers and are used to retain the refractory required inside the furnace wall area and for cooling the refractory surface that comes into contact with corrosive slag. The refractory material protects water wall tubes and pin studs from the environment created by fuel being burned.

When refractory failure occurs, it is a complex problem to solve. When refractory failure occurs in conjunction with a pin stud failure, it is doubly hard to solve. The failure is usually caused by a combination of factors. Finding the root cause of a stud and refractory failure requires an understanding of the slag and boiler environment.

Slag is the formation of molten, partially fused, or re-solidified deposits (ash) on furnace walls. Slag is a function of deposit temperature and deposit composition. Boilers are designed to maintain ash in a fluid state. For slag to adhere to a surface and form deposits, the particles of ash must have a viscosity low enough to wet the refractory-covered studded furnace wall tube. Iron raises all four values of ash fusion temperatures (initial deformation, softening, hemispherical, and fluid). So the greater the iron content in ash, the greater the difference in ash fusibility between the oxidizing and the reducing condition.

The amount of slag deposits formed inside a boiler can also depend on what type of coal is being used. For example, bituminous coal causes low to medium slagging; sub-bituminous coal (such as Powder River Basin or PRB) causes high slagging and has higher moisture content than bituminous coal; and lignite coal causes severe slagging. Along with the type of coal, air and fuel imbalance (stoichiometry) inside the furnace can also cause slagging, especially when the coal being used has a high iron content like bituminous coal does.

Slag deposits on boiler walls not only can cause stud and refractory failure, but can also cause many other boiler problems. Potential problems include the following:

  • Reducing furnace heat absorption
  • Raising gas temperature at the boiler gas exit, which can affect certain air pollution equipment
  • Causing fouling in the convection or heat-recover area of a boiler
  • Causing an increase in the spray flow of the attemperator
  • Interfering with ash removal

Due to the surface porosity of the refractory, slag can penetrate and cause deterioration of the refractory surface, wearing down exposed pin studs. To prevent this corrosive attack and give longer life to the refractory surface, it is possible to form a “frozen” layer of slag between the refractory surface and the molten slag. This thin, frozen slag layer can only be formed by the combination of the cooling action of studded tube walls, the thickness of the refractory material, and the thermal conductivity of the refractory material. Therefore, the higher the hot face temperatures, the less likely it is that the formation of a frozen slag layer will occur.

When burning coal, these factors inside the furnace can cause the refractory to fail:

  • Alkalis in the combustion of coal—such as sodium (Na) or “soda” and potassium (K) or “potash”—can chemically react with the silica found in refractory materials.
  • Sulfur found in the combustion of coal can combine with lime and iron oxide, and reduce the strength of a refractory material. In the presence of moisture, sulfur compounds and salts can form sulfurous and sulfuric acids. These acids can react with the “basic” components of refractory materials.
  • Hydrocarbons in unburned fuel (ash) can combine with a reducing atmosphere and react with the iron oxides in some refractory materials to form large carbon deposits. These deposits can cause a chemically induced spall on the surface of the refractory.
  • Temperature that refractory materials are exposed to can cause refractory failures. When operating temperatures are higher than recommended use limits of refractory materials, it can cause the refractory to melt.

Any number of things can cause a refractory to fail and expose the pin studs to the combustion environment. It is critical to choose a refractory material that can exist inside the furnace environment and not expose the pin studs. However, pin stud failure (when the studs are completely gone in a short time) normally occurs because of a weld failure or chemical attack created by the combination of sulfur and reducing atmosphere found inside the lower furnace. Understanding the welding process helps shed some light on why pin studs fail.

Pin studding is usually done using a semiautomatic stud welder. This apparatus consists of a welding machine, a weld timer, and a welding gun. This allows for the installation of many studs in a short time. A normal studded tube wall surface inside a furnace may have as many as 256 pin studs per square foot that are .375 inch in diameter and .75 inch long after welding. The cost (for material and labor) is almost 40 cents a pin stud, or $102 per square foot. Hand welding of pin studs can cost almost five times this amount. After the pin stud has been welded, it should be field-tested to withstand a 30-foot-pound (ft-lb) load.

Excluding weld failures and normal wearing away of the stud tip due to erosion, stud failure can also occur when the stud is exposed to sulfur and a reducing atmosphere. Sulfur content in coal that is greater than 2 percent, combined with a reducing atmosphere, can attack and destroy calcium-aluminate cement bond refractory materials. This can cause a complete refractory failure and expose the studs to the furnace environment. The sulfur, as found in most PRB-type coals, can change in a reducing atmosphere to a gaseous vapor. This sulfuric acid–type vapor can attack the surface of the studs and penetrate the weld joints between the studs and the tube wall surface. This will, over time, cause the weld joints to fail and the studs to pop off.

Only by understanding the boiler environment created by the fuel being burned can pin stud failures be avoided. In some extreme cases, the pin stud material has to be changed to meet this sulfuric acid condition.

Conclusion

Pin stud failures are a major concern for most power plants and can cost thousands of dollars of lost revenue if a plant is forced to shut boilers down to repair or replace failed and lost pin studs on lower furnace walls. Refractory that is properly selected and installed will last longer and help minimize pin stud wear and loss. However, eliminating pin stud failures begins with understanding ash and slag, as well as the environment created when burning coal inside the furnace area.

NIA Sites > Insulation Outlook Magazine > Global

The Truth About Wet Bottom Ash Hoppers: A Different Perspective on Refractory

Wet bottom ash hoppers may have a dirty job, but don’t let that fool you when it comes to how important this component is for a steam generating, coal-fired boiler. These water-filled hoppers are used to collect ash and slag, which are by-products of burning coal. A steam generating boiler simply cannot operate without an ash hopper.

The No. 1 reason for ash hopper failure is improper material selection or application. A properly installed ash hopper lining should last up to 10 years. Unfortunately, the average ash hopper lining today lasts only about 5 years, costing the power industry thousands of dollars in lost revenue. This article provides need-to-know information about this vital component.

General Information

As described, a wet bottom ash hopper is a water-filled steel tank with a protective lining used to collect bottom ash and slag from a steam-generating boiler that uses coal as its main source of fuel. It can be in the shape of a V, or it can be a multileveled, flat-bottom type. The number of hoppers required will depend on the size of the boiler and the amount of storage capacity required. Each V-shaped section or flat-bottom level usually has a separate discharge to remove the slag and ash collected within the ash hopper.

Two types of ash fall into a wet bottom ash hopper: coal ash and slag. Coal ash is the residual product left after burning of the fuel and slag, which is the formation of molten, partially fused, or re-solidified deposits on the furnace walls inside the boiler. The coal ash and slag fall into the water-filled ash hopper from the furnace above. This is emptied by opening a gate that allows the slag, ash, and slurry mix to flow into another watertight chamber. The ash, slag, and slurry mix is made up of various-size chunks of ash and slag. It passes through a grinder or crusher and onto a conveyor belt to be transported to a designated landfill.

Water is used to fill the ash hopper to make it possible to remove the ash and slag, and cool the exposed ash-hopper lining from the radiant heat coming from the furnace area above. The ash hopper is filled to a certain level, and the exposed upper portion of the ash-hopper lining must be water cooled. This is done by a water curtain arrangement at the top of the ash hopper that allows water to continually run over the surface of the lining material.

The ash-hopper lining is made of brick or refractory, or a combination of the two, and is used to protect the ash-hopper plate. The slag, ash, and slurry mix content can be very corrosive to the lining materials because of the surface porosity of the lining material. The slag, ash, and slurry can penetrate the surface of the lining and cause its deterioration.

Furnace vs. Hopper

Some steam-generating boilers require refractory inside the lower furnace area to protect the furnace water wall tubes from ash and slag created by the burning of fuel (such as coal, biomass, and black liquor). The refractory material used inside a furnace must be slag resistant and must have proper thermal conductivity to assist in the formation of a “frozen” layer of slag between the refractory surface and the molten slag. This thin slag layer is formed by the interaction of several factors—the cooling action of the studded furnace tube walls, the thickness of the refractory material, and the thermal conductivity of the refractory material. Inside wet bottom ash hoppers, however, no such frozen layer can exist to protect the refractory from the corrosive action of the combination of slag, ash, and water found inside the ash hopper.

Unlike the furnace area of a boiler, a wet bottom ash hopper lining must contend with the type of water being used to fill the ash hopper. Most power plants are located near a river and use river water to fill their ash hoppers. It has been found that when the phosphate levels of river water begin to approach 8 percent or greater, a chemical reaction can occur between the water pH and the lining material. To choose the right material for use inside a wet bottom ash hopper, one should consider that the lining material has to withstand the pH in the water and take into account the chemical makeup of the slag and ash that will fall into the ash hopper.

A typical wet bottom ash hopper analysis would involve the steps highlighted in Figure 1.

Basic Problems To Consider

When designing, relining, or repairing a wet bottom ash hopper, it is important to understand the following factors, which most often cause lining failure in a wet bottom ash hopper:

  1. Loss of water curtain above the water line. Loss of the water curtain can cause the surface of the refractory (usually about 1 inch thick) to pop off in sheets. This is due to rapid temperature changes in the lining materials’ surface.
  2. Improperly sized, spaced, or rotated anchors. Anchors should be sized at 2/3 or 3/4 of the total lining thickness, with one of the two tines or legs of the anchor longer than the other. Refractory anchors also should be spaced evenly in a staggered pattern (for example, 9- x 9-inch staggered centers) with each row of anchors rotated 90 degrees. This will help prevent the creation of a potential shear plane.
  3. Improper lining material selection. (See steps on page 24 for proper material selection.)
  4. Improper lining material installation. (This can include quantity or application.)
  5. Mechanical failure. An example of this is large slag deposits falling into the ash hopper.
  6. Expansion failure. This can including improperly installed lining or anchors, or choosing the wrong materials.

To choose a new lining material or understand why a lining failed, one must follow certain steps, such as those previously discussed in “Understanding Refractory Failure” (see the August 2006 Insulation Outlook).

Conclusions

An ash hopper is a collection area for ash and slag, and does not contribute to a boiler’s efficiency or energy savings. However, ash-hopper failure requires a boiler to be shut down. A complete ash-hopper replacement (including the plate and lining material) can be expensive and time-consuming. Complete replacement of an ash hopper can cost as much as $500,000 and take a month or more to complete. Only by following proper lining material selection, handling, and installation procedures can one prevent a lining failure and keep an ash hopper in operation. The longer a hopper is in operation, the longer a boiler makes money. It clearly pays to pay attention to wet bottom ash hoppers.

Figure 1
NIA Sites > Insulation Outlook Magazine > Global

Improving Firestopping for HVAC Duct Penetrations in Fire-Rated Walls

Firestopping non-dampered heating, ventilation, and air-conditioning (HVAC) duct penetrations in fire-rated walls is more involved than installing that ubiquitous red caulk into the space between the duct and the periphery of the opening. Because of the nature of thin sheet metal ductwork and the physics that come into play during the course of a fire, additional steps are required to ensure that such penetrants are properly protected. A cursory review of the UL Fire Resistance Directory, Volume 2 at the start of this decade would have shown 66 systems for HVAC ducts passing through walls. Today, a search would yield 237 total systems for HVAC duct penetrations through walls. In just 7 years, the industry has more than 3.5 times more designs representing advances in firestopping technology for a fairly common type of penetrating item.

Many HVAC ducts penetrating fire-rated walls are externally insulated with light-density glass fiber duct wrap, whether for energy conservation, efficiency increases, condensation control, or even sound attenuation. The average insulation contractor may be faced with situations where he or she needs to firestop HVAC duct penetrations through fire-rated walls. Additionally, many insulation contractors provide integrated firestop installation as a service. Knowledge of how to properly firestop HVAC ducts can go a long way toward making jobs run smoothly, minimizing costly delays, and increasing profitability.

Behavior of Sheet Metal Ducts Under Fire Conditions

Although there are a variety of different materials used to fabricate HVAC ducts—such as insulated panels, fiberglass reinforced plastic (FRP), aluminum sheet stock, or different grades of steel—sheet metal ducts fabricated from steel sheet stock are the most popular type of HVAC duct used in commercial construction. This is good from a fire-resistance perspective, as steel is inherently fire resistant. Ductwork fabricated from some of the alternate materials listed above can burn through, collapse, or melt, propagating fire through walls. It does not stop there, however.

Fabricating the duct from steel sheet stock does not mean it will be easy to firestop. Solids (for the most part) expand when heated and contract when cooled. Sheet metal expands dramatically when heated under fire conditions, which can have a profound impact on the performance of the firestop system. Square or rectangular ducts can deflect or distort when exposed to fire. This can cause gaps or voids to develop within a firestop system, allowing fire and smoke to pass through unchecked. Round ducts are stronger, due to their geometry, and will not collapse inward.

Given the propensity of square and rectangular ducts to deflect, distort, or collapse because of thermal expansion of the metal under fire conditions, virtually all designs require the use of steel retaining angles to prevent deflection. These L-shaped steel angles are cut to the length and width of the duct and attached by means of steel fasteners or welds to the flat sides of the duct. Some duct designs for smaller square or rectangular ducts may list the retaining angles as being optional. Such designs typically feature the use of an intumescent firestop product that will expand when heated to fill the voids as the duct sides deflect slightly. On larger ducts, even the most aggressive intumescent firestop products are incapable of completely filling the gaps that result from deflection of the metal if retaining angles are not used. Deflection will not be as great on a shorter span.

Traditional Methods

Since round HVAC ducts do not deflect, they are relatively easy to firestop. They can simply be sealed with a firestop caulk, such as an all-purpose intumescent firestop sealant. Firestopping square or rectangular non-dampered HVAC ducts is typically more involved. Generally, the first step is to pack the opening with forming material such as glass fiber, backer rod, or mineral wool. Some designs use mineral wool because its high-temperature capabilities give it the capacity to contribute a degree of fire resistance when installed in conjunction with firestop sealant. Other designs may use foam backer rod or glass fiber as a form to facilitate installation of the sealant along a long span. The next step is to install firestop sealant to the appropriate depth. The final step is to install the retaining angles to the flat sides of the duct. Although the user should consult the individual Underwriters Laboratories Inc. (UL) design, as a general rule the retaining angles should be sized so that they lap 2 inches onto the duct and 1 inch beyond the periphery of the opening. So if the space between the duct and the opening is 1 inch, a 2- x 2-inch angle would be required. In walls, the forming material, firestop sealant, and steel retaining angles are installed symmetrically on both sides of the wall.

It seems straightforward enough, but it is not typically a step-by-step process. The installation of the steel angles covers the opening, including the firestop sealant, commonly colored red for easy identification. This can interfere with the process of inspection. Therefore, in many jurisdictions, inspection is a two-stage process. The first stage is to inspect the installation of the firestopping materials installed into the opening, and the second stage is to inspect after installation of the steel retaining angles. This more drawn-out inspection process can have a tendency to cause schedule delays.

Fire and Smoke Dampers

Many ducts contain fire and/or smoke dampers that are designed to activate under fire conditions and seal off the path of fire and/or smoke internally within the duct. On many projects, there are questions about how to properly firestop ducts containing dampers where they breach fire-rated walls. This is a highly controversial topic. Some dampers require a specific clearance between the damper and the periphery of the opening to allow for expansion and contraction of the metal under normal operating conditions. In other cases, damper manufacturers contend that installing materials (such as compressed insulation) into this space can interfere with the action of the damper. There are many other concerns that need to be addressed when it comes to ducts containing dampers. Rather than trying to address all of those concerns, it’s best to contact the manufacturer of the damper for guidance when ducts containing fire and/or smoke dampers are encountered.

Insulated HVAC Ducts

Going back to the 2000 UL Fire Resistance Directory reveals just four designs for ducts insulated with light-density glass fiber duct wrap. Many additional designs are now available to cover various other permutations where steel ducts are insulated with light-density glass fiber duct wrap. Insulated steel ducts present a bit more of a challenge because the glass fiber begins to melt at about 1,200°F, a temperature reached within the first 10 minutes of a fire test. Also, because of the fluffy nature of light-density duct wrap, the firestopping material sometimes needs to be able to expand to fill a fairly large space.

Some designs that use an intumescent firestop sealant or wrap strip alone, without the need for steel retaining angles, have been developed. However, when the duct size increases substantially, steel angles are a definite requirement. There are two ways to firestop ducts insulated with glass fiber duct wrap when steel retaining angles will be used. The first method is a bit contentious among insulation contractors, manufacturers, and engineers. It is to install the firestopping materials into the space between the insulated steel duct and the periphery of the opening in the normal fashion, followed by installation of the steel angles directly to the steel duct. This is accommodated by slitting the insulation to permit the steel angle to attach to the duct. Some argue that this is a situation ripe for creating condensation problems. The preferred method in many cases is to not breach the vapor barrier by installing the steel angles directly over the duct wrap, compressing the duct wrap during installation. However, it is important to verify that a UL system allows for the particular configuration of the steel retaining angles.

Some HVAC ducts are being protected with proprietary high-temperature duct wraps to resist the spread of fire from compartment to compartment without the aid of fire dampers. These systems address insulation, integrity, and stability of the system, and they even have their own category in both the UL Directory and the Intertek/OPL Directory. Unless otherwise specified by the design, steel retaining angles are not required, even on the largest of such ducts. Where these ventilation ducts pass through fire-rated assemblies, openings such as these are firestopped. Designs exist in both the UL Directory and the Intertek/OPL Directory that show how to properly firestop such systems. In many cases, a firestop system will consist of caulk and a backing material, or of caulk alone.

Conclusion

The evolution of firestopping has led to significant improvements over traditional methods. Continuing training and educational efforts are leading to a heightened awareness of the importance of proper firestopping and its impact on improving both safety and property protection. Authorities are now well versed in the requirements for proper firestopping. They are also trained to understand how penetrants and materials react together. This knowledge helps in the proper selection and installation of firestopping systems for HVAC ducts, as well as other types of applications. The UL Fire Resistance Directory, Volume 2, as well as the free online searchable database at www.ul.com, are great sources for information on firestopping. Also, many of the larger firestopping manufacturers have highly qualified technical personnel who can explain the subtle nuances of firestopping, as well as skilled field personnel who can conduct more specific training.

Figure 1
Figure 2
Figure 3