Generally, the principles of condensation control are very straightforward, but let’s consider the consequences of an <\/p>\n
insulation system failure in a condensation control application. Insulation, including accessory products such as adhesives, <\/p>\n
mastics, caulks, pipe-hanger supports, jackets and coatings, should all be considered as a system. Consideration of the <\/p>\n
consequences of a failure should drive the initial design and installation of the system. <\/p>\n
The principles of preventing condensation are very simple: Maintain the surface temperature of the insulation above the dew <\/p>\n
point, and prevent any intrusion of moisture or moist air into the insulation system (particularly between the insulation and <\/p>\n
the pipe being insulated). <\/p>\n
These principles are accomplished through proper insulation design (the correct selection of type and thickness), <\/p>\n
installation and maintenance. As a matter of fact, maintenance of an insulation system can be greatly reduced if the design <\/p>\n
accounts for the environmental conditions that the insulation will encounter. Proper completion of the above steps will <\/p>\n
ensure a successful project. <\/p>\n
Pipe size, ambient temperature, pipe temperature, wind speed, emissivity of insulation or jacket, location of application, <\/p>\n
and most importantly, the relative humidity, must also be considered for a proper design. <\/p>\n
Most project specifications will state that the insulation should be installed according to the manufacturer’s <\/p>\n
recommendations. Some basic installation guidelines are often given as well. However, if the design engineer fails to <\/p>\n
consider the level of difficulty for properly installing an insulation system, particularly under the labor, site and climate <\/p>\n
conditions in which the insulation system will be installed—this can play a major role in the failure of the insulation <\/p>\n
system. Labor experience, severe weather conditions, logistics and project timetables all must be considered in the <\/p>\n
installation step. Failures during installation always result in finger-pointing, but can often be avoided if potential <\/p>\n
installation problems are considered in the initial plan. <\/p>\n
Periodic maintenance of the insulation system is critical for preventing premature failure of the system and for reaching the <\/p>\n
life expectancy of the system. When you consider the lifespan of the insulation system, it is often less expensive to build <\/p>\n
more reliability into the insulation system in the beginning than it is to rely on excessive maintenance afterward. This is <\/p>\n
especially true for installations in which the required maintenance may not get done, resulting in a premature and costly <\/p>\n
system failure. <\/p>\n
If the insulation system is designed and installed properly, the worst failure scenario would be condensation formation on <\/p>\n
the outside of the insulation in those extreme cases when the actual dew point exceeds the dew point limit of the design. If <\/p>\n
the insulation is properly designed and prevents water intrusion, moisture on the insulation surface generally will not <\/p>\n
result in a catastrophic failure of the system: It either will be a short-term problem or will be correctable by adding <\/p>\n
insulation thickness. <\/p>\n
Unfortunately, however, most condensation control application failures do result in catastrophic or complete insulation <\/p>\n
system failures. Unlike insulation on hot systems where a failure may only result in excessive loss of energy, failures in <\/p>\n
below-ambient systems can have major consequences and are usually easily detected. Even in concealed spaces, the consequences <\/p>\n
of condensation control failures usually show evidence quickly, resulting in costly repairs. <\/p>\n
Failures are often caused by the inadequate performance of special areas that are difficult to insulate, such as pipe hangers <\/p>\n
and valves. Another potential cause of failure is when work needs to be done by another tradesman (i.e., an electrician) and <\/p>\n
in the process of doing his work he damages the insulation. The insulation then needs to be replaced. <\/p>\n
In some instances, design flaws can result in failures, such as not leaving adequate clearance for insulation to be <\/p>\n
installed, or failing to specify the adequate insulation for items such as valve stems\/handles. Condensation control <\/p>\n
applications require all areas be insulated and sealed properly. The insulation system is only as good as its weakest link. <\/p>\n
The typical consequence of condensation control failures is saturated insulation—particularly if the insulation is not <\/p>\n
closed-cell or if the jacket protecting an open-cell product has failed. Moisture will contribute to the following <\/p>\n
conditions: <\/p>\n
- \n
- \nLoss of insulation value: One percent weight gain due to moisture results in 7.5 percent loss in thermal efficiency. <\/p>\n
Reduction in insulation value can contribute to further insulation failure, quickly resulting in a total failure of the <\/p>\n
system.<\/li>\n
- \n\tIncreased insulation weight: This can cause it to deform and possibly fall from the pipe.\n<\/li>\n
- \n\tPotential corrosion of pipes.\n<\/li>\n
- \n\tMold and mildew on the insulated surface itself as well as surrounding areas: ceiling tiles, carpets, throughout the <\/p>\n
insulation and under jacketing—especially in open-cell insulation. Mold and mildew could potentially affect the entire <\/p>\n
building if they get in the air stream.\n<\/li>\n
- \n\tLoss of energy and higher operating cost.\n<\/li>\n
- \n\tUnsafe conditions: Water dripping and accumulating in ceiling tiles or on floors, possibly even forming ice, can <\/p>\n
create slip hazards to the personnel below. Condensation falling onto electrical equipment can cause shock hazards and can <\/p>\n
damage sensitive equipment.\n<\/li>\n
- \n\tCondensate dripping can also contaminate the product being produced below the piping system.\n<\/li>\n
- \n\tUnpleasing aesthetics, such as water-stained ceiling tiles, walls and carpets, as well as deformed and discolored <\/p>\n
insulation. <\/li>\n<\/ol>\n
The costs associated with remediation of the above consequences can be very expensive and generally far exceed the cost of <\/p>\n
the insulation system. Repairs to the system, especially if the pipes are in concealed spaces of occupied areas, are several <\/p>\n
times the cost of the insulation system. If a production facility has to be shut down for any length of time to make repairs, <\/p>\n
the cost of lost production can mount up. Product quality may suffer if manufacturing processes are not kept at the correct <\/p>\n
temperature, and overall plant efficiency may suffer as well. If the problem exists in a plenum or duct area, indoor air <\/p>\n
quality will suffer, causing worker discontent and possible lost time on the job. In many cases, the above costs are brought <\/p>\n
out in lawsuits, which can significantly increase the costs associated with the problem. <\/p>\n
Moisture intrusion between the insulation and pipes caused by seam failure or saturated insulation can result in the need to <\/p>\n
replace the piping. This will result in shutting down the facility to make the repairs. The cost to shut down a facility <\/p>\n
multiplies the cost factor. <\/p>\n
\nSome installation techniques that can be used to reduce the chances of a failure or lessen the costs associated with a <\/p>\n
failure are:<\/p>\n
- \n
- \n\tPrefabricate as much of the insulation as possible under ideal conditions prior to taking it to the job site, either <\/p>\n
at the manufacturer’s site or in the contractor’s shop.\n<\/li>\n
- \tAdhere the insulation to the pipe every 20 feet, creating a water dam—this contains moisture from a failed area and\n
prevents its travel to other areas of the system.\n<\/li>\n
- \tUse systems with additional margins of safety, such as closed-cell insulation under a waterproof jacket or mastic.\n<\/li>\n
- \tUse robust jacketing systems outdoors because they are designed for years of service and low maintenance.\n<\/li>\n
- Use jacketing systems that adhere to the insulation in order to prevent moisture travel between the insulation and the\n
jacket.\n<\/li>\n
- Use adequate insulation thickness based on the design dew point. It is better to err toward “too thick” as the added cost\n
of the insulation will be a small part of the total cost of the installed system, and will cost much less than if the system <\/p>\n
fails.\n<\/li>\n
- \tInsulate all areas of the system: Remember that the system is only as good as its weakest link. Using accessories\n
such as pre-insulated pipe hangers is a good idea—they save time and ensure proper insulation thickness. <\/li>\n<\/ol>\n
Mold and mildew are the new key buzzwords in regards to liability. Insulation systems that limit moisture absorption or have <\/p>\n
secondary layers of defense against moisture intrusion will greatly reduce liability for mold and mildew problems. Designers <\/p>\n
of schools, hospitals, hotels and public buildings are looking for solutions to the mold\/mildew issue. Preventing moisture in <\/p>\n
the system will eliminate the issue. Selecting the proper materials, maintaining the material’s integrity at the job site and <\/p>\n
correct installation are all key to prevention. <\/p>\n
Generally, catastrophic failures can be traced back to seam failures (caused by improper installation) or failure of the <\/p>\n
jacketing that protects open-cell insulation, both of which can be minimized in the design stage of the project. Insulation <\/p>\n
systems that are easier to install should be a clear choice. Jacketing systems that have safety factors built in should also <\/p>\n
be a clear choice. The initial cost of ensuring proper installation can be easily justified when one considers the future job <\/p>\n
site labor savings and the increased reliability of the system. <\/p>\n
Installing a system that you know will require a great deal of maintenance is a failure in the making. You must consider the <\/p>\n
conditions in which the insulation will function when designing a system. For indoor applications, jacketing on the <\/p>\n
insulation may or may not be needed, depending on the insulation selected and the expected use. For example, applications <\/p>\n
that will experience mechanical abuse or wash-downs should be jacketed. Outdoor applications (e.g., rooftop applications) <\/p>\n
will always need to be protected, not only from UV rays but also from other environmental factors. Outdoor applications with <\/p>\n
extreme conditions (e.g., coastal or offshore applications) will require more robust jacketing. In many cases, adhesives, <\/p>\n
mechanical fasteners and silicone sealants will be required to keep the insulation system moisture-proof. It should be <\/p>\n
expected that people will walk on, lean ladders against and generally abuse the insulation system. A sign directing personnel <\/p>\n
not to walk on the insulation is not adequate. Jacketing should be selected to be robust and, in the case of damage, easy to <\/p>\n
repair. <\/p>\n
The reliability of the insulation system should be of key concern in the design phase. As stated above, the primary reason <\/p>\n
insulation systems fail is because they are improperly installed. Many design engineers have never seen insulation installed <\/p>\n
and underestimate how difficult it is to provide a correct installation. It is the responsibility of the insulation <\/p>\n
manufacturer, distributor and contractor to advise the design engineer of systems that are easier to install and are more <\/p>\n
reliable in the field, even if the initial costs are higher. Standing behind the old adage, “I gave him what he asked for,” <\/p>\n
will not benefit our insulation industry, nor will it build the positive relationship that is needed between the design <\/p>\n
engineer and the insulation industry. We should not aim to be considered a manufacturer, distributor or a contractor, but to <\/p>\n
be a highly specialized consultant to the design engineer. <\/p>\n
\nThe cost of a good insulation system can be easily calculated. The cost of the payback in terms of energy savings can also be <\/p>\n
easily calculated. The cost of an insulation system failure can be priceless. Effective condensation control is not a matter <\/p>\n
of chance, compromise or cost minimization: From the beginning of a project, it requires communication among all parties <\/p>\n
involved—the engineer, the insulation contractor, the manufacturer of the insulation and accessory materials, and the <\/p>\n
facility owner.\n<\/td>\n
<\/td>\n \n \nClick Photo to Enlarge<\/h5>\n<\/div>\n
![\"Figure](\"..\/articles\/pubimages\/IO\/05\/IO050701_01.jpg\"\n)
<\/p>\n<\/p>\n
Figure 1<\/div>\n<\/span><\/p>\n
\t <\/a> The consequences of condensation failures include mold and mildew, which can potentially <\/p>\n
affect the entire building if they get in the air stream.<\/span><\/p>\n
\t <\/p>\n
![\"Figure](\"..\/articles\/pubimages\/IO\/05\/IO050701_02.gif\"\n)
<\/p>\n<\/p>\n
Figure 2<\/div>\n<\/span><\/p>\n
\t <\/a><\/p>\n
\t <\/p>\n
![\"Figure](\"..\/articles\/pubimages\/IO\/05\/IO050701_03.gif\"\n)
<\/p>\n<\/p>\n
Figure 3<\/div>\n<\/span><\/p>\n
\t <\/a><\/p>\n
\t <\/p>\n
- \n\tPrefabricate as much of the insulation as possible under ideal conditions prior to taking it to the job site, either <\/p>\n
![\"Figure](\"..\/articles\/pubimages\/IO\/05\/IO050701_04.jpg\"\n)
<\/p>\n![\"Figure](\"..\/articles\/pubimages\/IO\/05\/IO050701_05.jpg\"\n)
<\/p>\n