Solutions Center

Mechanical Insulation FAQs

What is mechanical insulation?

Mechanical insulation is used to cover pipes, ducts, tanks, and equipment in commercial or industrial environments and is typically relied upon to control temperature for a much broader range of temperature variances that of a typical home. Home or residential insulation is typically found in the exterior walls and attics and is used to keep the home environment a consistent, comfortable living temperature. The temperature differential in a home insulation environment is in most cases far less than that of a typical commercial or industrial application. As an example, a typical home application may be to maintain an interior air temperature of 76°F against an exterior temperature of 10°F in the winter and 100°F in the summer. Thus the temperature differential could range between 24°F to 66°F. In many commercial and industrial applications, temperature differentials range from 20°F to 600°F or more.

Mechanical insulation is primarily used to limit heat gain or loss from surfaces operating at temperatures above or below ambient temperature. The opportunities to limit that gain or loss are far greater in the commercial and industrial sectors versus the residential sector.

How do you choose the right insulation for the job?

Finding the 'right' insulation begins with asking some basic questions such as:

1. What is the operating or line temperature of the system your customer needs to insulate? 

In general, systems needing insulation can be divided into three temperature ranges:

•    Low Temperature Range (-100°F to 60°F) Refrigeration, cold/chilled water and commercial heating and cooling systems.

•    Medium Temperature Range (61°F to 600°F) Hot water and steam, power/process piping, ovens and stacks.

•    High Temperature Range (601°F to 1500°F) Power generation, turbines, kilns, smelters, exhaust systems and power piping.

2. Is the system outdoors or indoors - or a combination of both?

This will help you determine whether or not the system and the insulation needs protection from weather, corrosive atmospheres, water or chemical washdowns, abuse or other conditions.

3. Is the ambient temperature constant...or will it fluctuate?

The answer to this question will guide you in the selection of the appropriate thickness to protect against condensation, heat loss or gain or other temperature control problems.

Use our Product Selector Guide to get started.

Where can I get information on specification requirements?

Understanding specifications is an important part of the job. We recommend NIA’s Guide to Insulation Product Specifications. (download here)

Important testing, codes and standards setting organizations critical to ensuring the performance of insulation procedures and systems include:

•    ASTM—American Society for Testing Materials

•    ASHRAE—American Society of Heating, Refrigerating, and Air Conditioning Engineers

•    U.S. Government—publishes federal and military specifications for insulation materials

•    MICA—Midwest Insulation Contractors Association

•    PIP—Process Industry Practices

Some of the performance specifications that you will need to become familiar with on the job include water vapor transmission, compressive strength, and fire hazard classifications. Example: You'll find that a 25/50 rating for fire hazard classification is required for some codes. The 25 represents the flame spread index and 50 represents smoke developed index when compared to cement as "0" and red oak as "100".

For technical specs on any Armacell product, please contact our Technical managers.

What is meant by K-Factor, R-Value, and C-Factor?

K-Factor (Thermal Conductivity Factor) - The measure of heat in Btus that pass through one square foot of a homogeneous substance, 1 inch thick, in an hour, for each degree F temperature difference. The lower the K-value, the higher the insulating value. Textbook definition: The time rate of steady heat flow through a unit area of a homogeneous material induced by a unit temperature gradient in a direction perpendicular to that unit area.

Insulation materials usually have K-Factors less than one and are reported at what is called Mean Temperature. To determine the mean temperature, measure the surface temperatures on both sides of the insulation, add them together and divide by two.

When comparing the insulating value of different types of insulations, it's important to look at K-Factor and the mean temperature. As mean temperatures rise, so does the K-Factor.

C-Factor (Thermal Conductance Factor) - C-Factor is the number of Btus which will pass through 1 square foot of material with 1°F temperature difference for a specified thickness. The C-Factor is the K-Factor divided by the thickness of the insulation. The formula is the reciprocal of the R-Factor formula. The lower the C, the better the insulator.

R-Value (Thermal Resistance Value) - The National Commercial & Industrial Insulation Standards Manual defines R-Value as a measure of the ability to retard heat flow rather than to transmit heat. "R" is the numerical reciprocal of C, thus R=1/C. Thermal resistance designates thermal resistance values: R-11 equals 11 resistance units. The higher the "R", the higher (better) the insulating value.

What is the difference between Mean Temperature and Ambient Temperature?

Temperature is a property unto itself. It is not a measurement of the amount of heat present. For example, if you pour two cups of coffee, one to the brim, and the other only halfway, the temperature will be the same in both cups, but the partially filled cup will only contain half the heat (Btus) of the full one.

Mean Temperature is the average of the sum of a hot surface temperature and a cold surface temperature. Insulation conductivity (K-Factor) is tested at a number of mean temperatures to develop conductivity curves that simulate actual service conditions under which insulation systems are used. All conductivity figures (K,C,R) must be qualified by a mean temperature.

Ambient Temperature is the average temperature of the medium, usually air, surrounding the object under consideration.

How do I find Safety Data Sheets (SDS)

There are links to all of our Safety Data Sheets here.

Does Armacell make insulation suitable for high temperatures (601°F to 1200°F)?

Yes. Armacell's aerogel blanket, ArmaGel HT, provides CUI mitigation and thermal insulation for temperatures up to 1200°F. *Please consult Armacell for insulation application temperatures above 600°F.

What kind of things should be considered when insulating cold process systems?

•    Low temperature systems such as those needed for refrigeration or chilled water range from -100°F to 31°F. Supermarkets and food processing are typical of these system environments. Cold water systems such as those used for water supply to HVAC systems generally range from 32°F to 60°F.

•    Cold water systems require special attention because one must design for protection against condensation and consider the affect of moisture or water vapor transmission (WVT) on the insulation system.

•    WVT tells you how much water will be transmitted through an insulation system under certain conditions. Different insulation systems, vapor retarders and installation methods will affect the WVT of the system.

•    Condensation control and process control are two major reasons for insulating low temperature systems. When equipment or piping operates at temperatures lower than the ambient air, moisture in the air will condense or freeze on, or within, the insulation surface - or on the cold pipe surface. Unless the system is protected by sufficient thickness and by adequate vapor retarders, the insulation may become wet, causing corrosion, and causing it to become ineffective.

How does insulation help control condensation?

When piping and equipment operate at temperatures lower than the ambient air, moisture in the air will condense, or freeze, on or within the insulation surface - or on the cold pipe surface. Unless the system is protected by sufficient thickness and by adequate vapor retarders, the insulation can become wet, causing corrosion, and causing it to become ineffective.

Specifying closed-cell elastomeric insulation, like ArmaFlex, at the sufficient thickness is the most effective means of providing a system for controlling condensation on the membrane surface and within the insulation system on cold piping, ducts, chillers and roof drains. Sufficient insulation thickness is needed to keep the surface temperature of the membrane above the highest possible design dewpoint temperature of the ambient air so condensation does not form on the surface.

For most insulation products, an effective vapor retarder system is needed to restrict moisture migration into the system through the facing, joints, seams, penetrations, hangers, and supports. With a closed-cell elastomeric foam product like ArmaFlex, moisture migration is not a problem; moisture cannot permeate the insulation layer. Controlling condensation in the mechanical system will:

•    Prevent degrading system service life and performance.

•    Resist mold growth and the potential for health problems resulting from water condensate.

•    Reduce the likelihood of corrosion of pipes, valves and fittings caused by water collected and contained within insulation system.

How and why is insulation used to control sound?

Sound attenuation, or the limiting of sound propagation from one area to another, can be achieved through the application of insulation materials to encase or enclose the noise generating source, forming a sound barrier between the source and the surrounding area.

The purposes of applying sound attenuation materials are to:

1.    Reduce noise levels emitting from machines, equipment, pipe lines or enclosures.

2.    Reduce general noise level in plant areas.

3.    Provide for better work conditions.

4.    Comply with noise level standards of OSHA and EPA.

5.    To meets requirement for Indoor Environmental Quality in green building standards, Like LEED®.

AP ArmaFlex and AP CoilFlex are particularly good at absorbing noise at the critical low 500 Hz levels. They can be applied as Duct liner or Wrap to reduce noise transfer or dampen vibration sound.

How do you determine which is the right protective covering and finish?

The efficiency and service of insulation is directly dependent upon its protection from moisture entry and mechanical and chemical damage. Choices of jacketing and finish materials are based upon the mechanical, chemical, thermal and moisture conditions of the installation, as well as cost and appearance requirements. Protective coverings are divided into six functional types:

•    Weather Barriers

•    Vapor Retarders

•    Mechanical Abuse Coverings

•    Corrosion and Fire Resistant Coverings

•    Appearance Coverings and Finishes

•    Hygienic Coverings

What is R-value?

R-value measures insulation's resistance to heat flow. It can also be referred to as "thermal resistance." The higher the R-value, the greater the insulating power. All materials having the same R-value, regardless of type, thickness, or weight, are equal in insulating power. The R-value of different insulating materials must be based on test methods established by the American Society of Testing and Materials (ASTM). Don't forget that R-values are determined by material type, thickness, and installed weight per square foot, not by thickness alone. Insulation helps keep your home cool during the summer months and warm during the winter months.

What is the difference between fiberglass, rock and slag wool, cellulose, foam and elastomeric foam insulations?

Fiberglass is made from molten sand or recycled glass and other inorganic materials under highly controlled conditions. Fiberglass is produced in batt, blanket, and loose-fill forms.

Rock and slag wool are manufactured similarly to fiberglass, but use natural rock and blast furnace slag as its raw material. Typical forms are loose-fill, blanket, or board types.

Cellulose is a loose-fill made from paper to which flame retardants are added.

Foam insulations are available as rigid boards or foamed-in-place materials that can fill and seal blocks or building cavity spaces. Foams are also used in air sealing to fill gaps, cracks, or openings.

Reflective materials are fabricated from aluminum foils with a variety of backings such as polyethylene bubbles and plastic film. Reflective insulations retard the transfer of heat; they can be tested by the same methods as mass insulation and therefore assigned an R-value.

Elastomeric foam insulation is a flexible, closed-cell, foam based on NBR or EPDM rubber. Flexible elastomeric foams exhibit such a high resistance to the passage of water retarders that they do not generally require additional water-vapor barriers. Such high vapor resistance, combined with the high surface emissivity of rubber, allows flexible elastomeric foams to prevent surface condensation formation with comparatively small thicknesses.

As a result, flexible elastomeric foams are widely used on refrigeration and air-conditioning pipework. Flexible elastomeric foams are also used on heating and hot-water systems.

The three main components used in the manufacturing of elastomeric closed cell foam insulation include the following:

•    Synthetic rubber blend, typically nitrile butadiene rubber (NBR) and/or ethylene-propylene-diene monomer (EPDM)

•    Polyvinyl chloride (PVC)

•    A chemical foaming agent

How much clearance do I need to leave for my mechanical insulation for pipes and ducts?

To ensure the proper installation of mechanical insulation and later service access, adequate clearances must be designed into the mechanical equipment and systems to be insulated. You can use our ArmaWin tool to calculate proper thickness requirements before the plans are finalized.

Where in the specification will mechanical insulation be addressed?

Construction Specifications Institute (CSI) and Construction Specifications Canada (CSC) jointly publish a document called MasterFormat® which is the master list of numbers and titles for organizing information about construction requirements, products, and activities into a standard sequence. In addition to other applications MasterFormat is the accepted North American standard for assigning numbers and titles to specification sections and has been adopted by all Federal government agencies and the private sector design and construction industry throughout the U.S. and Canada.

Mechanical insulation is located in several divisions:

21 07 00 – Fire Suppression System Insulation

•    21 07 16 - Fire-Suppression Equipment Insulation

•    21 07 19 - Fire-Suppression Piping Insulation

22 07 00 – Plumbing Insulation

•    22 07 16 - Plumbing Equipment Insulation

•    22 07 19 - Plumbing Piping Insulation

23 07 00 – HVAC Insulation

•    23 07 13 - Duct Insulation

•    23 07 16 - HVAC Equipment Insulation

•    23 07 19 - HVAC Piping Insulation 

What are the main criteria to be considered when specifying mechanical insulation?

There are many design objectives in a mechanical insulation system that can be achieved specifying the right insulation installed in the proper manner.

Design Objectives


•    Condensation Control

•    Energy Efficiency

•    Economic Considerations - Return on Investment

•    Environmental Considerations - Sustainability

•    Fire Safety

•    Freeze Protection

•    Personnel Protection - Safety

•    Process Control

•    Acoustics-Noise Control

Other Design Considerations

•    Abuse Resistance

•    Corrosion Under Insulation

•    Indoor Air Quality

•    Maintainability

•    Regulatory Considerations

•    Service Life

When does an insulation application need an additional covering or coating?

All exterior applications of foam insulation need to be protected from the sun's damaging UV rays. All of Armacell's elastomeric foam insulation materials should be protected with WB Finish to reduce the effects of UV and make the insulation last longer.

Some applications require an outer cladding for protection from puncture, UV damage or even for aesthetics. We offer several options including:

ArmaTuff: Insulation for outdoor installations with a durable UV-protective metal cladding.

WB Finish: A white water-based acrylic coating supplied in gallon or quart containers for use over all forms of ArmaFlex Insulations. It provides a protective finish suitable to both indoor and outdoor applications.

What is the right adhesive for my installation?

This depends on the product and your specific application. Our ArmaFlex 520 adhesive is the workhorse of our adhesive line. It is a solvent-based contact adhesive that is easy to apply, quick drying and strong, for tight seams. ArmaFlex 520 Black gives you the same great properties as the regular adhesive, but in a black formulation that gives a cleaner visual to the final installation. ArmaFlex 520 BLV Adhesive is an adhesive with low VOCs for installations that require a low-emitting adhesive. HT 625 Adhesive is a contact adhesive design for high temperature applications and remains thermally stable up to 150°C and 300°F. ArmaFlex® Low VOC Spray Adhesive is supplied in 27 pound aerosolized canisters for faster easier applications for large installations like tanks, vessels or ducts.

What is the advantage of using an ArmaFix pipe hanger instead of the typical block and dowel construction?

ArmaFix EcoLight are quick, innovative alternatives to traditional block and dowel pipe supports. The engineered, foam-to-foam solutions provide optimum load bearing while protecting against thickness compression and condensation gaps that can compromise system integrity. To make installation even faster, Armafix longitudinal seams are self-adhering. The ends are easily sealed with ArmaFlex 520, 520 Black or 520 BLV Adhesive to ensure a completely sealed system, with worry-free performance. For some applications Insuguard shields and saddles are recommended.

When is it recommended that I use insulation tape over adhesive?

AP/ArmaFlex Insulation Tape is made of the same high-quality elastomeric insulation as AP/ArmaFlex sheet material. Tape provides a fast, easy method of insulating pipes and fittings. The tape may be used in conjunction with AP/ArmaFlex Pipe and Sheet Insulation. Its greatest advantage, however, is the ease with which it can be used to insulate short lengths of pipe and fittings in congested or hard-to-reach areas where it may be difficult to use standard adhesive methods.

What are fittings?

Armacell Pre-fabricated Fittings are the premier prefabricated fittings for ArmaFlex pipe insulation systems. Together with the ArmaFlex tubes, they provide complete system integrity for retarding heat gain and controlling condensation drip from chilled-water and refrigeration systems. They are available in many sizes, fabricated in T’s, elbows, P-traps and other useful shapes. They speed up installation saving time and labor in the field.

What formats are available in ArmaFlex products?

AP ArmaFlex is available in tubes, sheets and rolls of many sizes, thicknesses, widths and lengths. Check the product specs of each product to determine the size and format which is best for your project. Tubes are a natural for pipe installations, however, some large pipes might require sheets or rolls to cover the circumference of the system. Sheets and rolls are also convenient for large ducts, vessels, tanks or any odd-shaped mechanical. The beauty of elastomeric foam material is its conformability and versatility. It can be cut cleanly and fabricated into complex shapes.

Can you explain the difference between a duct liner and a wrap?  Why would you use one and not the other?

Duct liner is the product that is used to line the inside of the duct.

Lining a duct with elastomeric foam like AP ArmaFlex, AP CoilFlex and AP SpiralFlex offers thermal protection from energy loss and condensation control, but also brings superior sound absorption and vibration dampening from airborne and structure-borne HVAC noise. Another advantage is that duct fabricators may be able to pre-line ducts on automatic coil lines in the shop, saving field installation time.

Duct wrap is the product that will be attached to the outside of the duct.  Wrapping a duct may be the best option when access to the inside of the duct is impossible, perhaps during a retrofit of an existing mechanical system or renovation of an older building. Wrapping the duct with AP ArmaFlex still provides excellent protection from energy loss or condensation control as well as some vibration dampening benefits.

Can I use the same insulation as a Liner or as a Wrap? 

In most cases the AP ArmaFlex can be used as either a duct liner or a duct wrap.  The AP CoilFlex is designed as a duct liner only.

What are the basics for a good installation for elastomeric foam insulation?

We have free installation guides available for all of our products, duct liner, duct wrap etc. here in the Solutions Center. Or watch our videos, here.

Is elastomeric insulation good for temps as high as 400°F or more?

No.  The elastomeric high temp product is UT SolaFlex but is can only be used up to 300°F

What is the temperature range of elastomeric insulation?

Our AP ArmaFlex products have a temperature range from -297°F to 220°F. Our UT SolaFlex product can be used from -297°F to 300°F

If I have a metallic outdoor duct, would there be any advantage to use elastomeric foam material? 

Yes, if you have a noise problem it would help to use a duct liner on the inside which will help with the condensation control as well as the noise.  If you are running cold air for an air conditioning system, the insulation on the interior or exterior will help with energy conservation as well as condensation control.

Look for products specifically for outdoor applications that have durable claddings and UV protection.

Can a duct with ArmaFlex or CoilFlex duct liner be cleaned?

The North American Duct Cleaners Association (NADCA) which is the duct cleaning trade organization in the US has endorsed our product. Their members often replace torn fiberglass with AP ArmaFlex insulation.  The ArmaFlex and CoilFlex products are very easy to clean with the proper brushes and automatic duct cleaning equipment.  Much easier and less damage, in fact, than fiberglass.

Can Elastomeric foams be directly exposed to fire? How are they rated?

Most of the elastomeric products that Armacell produces do meet ASTM E84 at 25/50 which means they can be used in air plenums. ArmaFlex products are also self-extinguishing which means that if the flame source is removed the product will burn itself out.

What is the price difference between using fiberglass and ArmaFlex? 

You would need to check with your local distributor for exact pricing.  Normally the elastomeric foam is more expensive than fiberglass, but due to its stability and resistance to moisture or surface damage, it will probably last longer and retain its thermal integrity over time.

How are your products tested?

We normally test ASTM E84 at an independent lab.  Other tests are done both here in-house and at 3rd party labs.  If you have a specific request or a specific test request please contact our technical manager. 

Does ArmaFlex insulation need an additional vapor retarder?

No, the nature of closed-cell foam is that it will not absorb or wick moisture. No vapor retarder is required on indoor applications.

Where are your products made?

Armacell operates 6 manufacturing facilities in the North America. There are 24 other Armacell plants across the globe.

What is Microban® antimicrobial product protection?

Microban technology is built-in antimicrobial protection for solid products, coatings and fibers. Microban antimicrobial protection gives products an added level of protection against damaging microbes such as, bacteria, mold and mildew that can cause stains, odors and product deterioration.

How do products with Microban® antimicrobial protection work?

Microban® protection is built-in to the product during the manufacturing process. When microbes come in contact with the product surface, Microban protection penetrates the cell wall of the microorganism and disrupts cell functions disabling the microorganism's ability to function, grow and reproduce. Read more about Microban protection here.

What benefit do my customers get from products with Microban® antimicrobial protection?

Microban protection continuously fights the growth of damaging microbes such as, bacteria, mold and mildew that can cause stains, odors and product degradation. Microban protection makes products easier to clean and keeps them cleaner and fresher between cleanings.

What types of microorganisms does Microban® protection work against?

Microban® antimicrobial protection is effective against most common bacteria, molds and fungi that cause stains, odors and product degradation.

How do I know that Microban® antimicrobial product protection is safe?

Microban® technology has undergone extensive independent laboratory testing and has a long history of safe use. It is registered with the EPA for all applications in which it is used. Microban additives can be found in the products of leading consumer, industrial and medical products manufacturers around the world.

Does Microban® protection begin working immediately?

Microban® protection begins to work as soon as the microorganism comes into contact with the product surface. It then works continuously to maintain a consistently lower bio-burden than would be expected on a product without Microban® antimicrobial protection. Under the right conditions, microbes on an untreated surface can double every 20 minutes! Microban protection is not a disinfectant; normal cleaning practices should be maintained.

How long does Microban® antimicrobial protection work?

Microban® protection is built-in during the manufacturing process and will not wash off or wear away. Microban protection is engineered to provide continuous antimicrobial product protection for the useful lifetime of the product.

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