CRT Tipster's Blog

During the life of the insulation, literally millions of cubic feet of air are passed through the AHU daily.  Air contains small particulate matter, the majority of which is below the limits of human visibility.  Air contains  ordinary dirt particles, and  microbial spores such as bacterial or fungal spores.  It is normal that these particulates impinge upon and get entrapped within the insulation.

When microbial spores impact the insulation, they often grow and amplify within the insulation itself.  This results in VOC emissions (odors) and a source of contamination for the rest of the air handler.

It is unfortunate that fiberglass cannot be cleaned or sanitized to help remove embedded microbes.  This is due to the nature of the fiberglass itself.

A workable solution to prevent fiberglass emissions and at the same time eliminate the potential for embedded microbes is to coat the surfaces of insulation.

Flex Seal ™ first brought on the market in the 1990s, was developed by our firm to address typical fiberglass insulation problems.

FIex Seal is applied using a professional  airless sprayer.   The coating of the insulation is done in place within the air handler, and takes a minimal amount of time.

A flexible white surface is obtained that is easily cleanable with a rag or brush.  This allows for the user to maintain the cleanliness of interior surfaces.

Flex Seal contains an antimicrobial to prevent  attack of microbes on its surface while controlling odors.   Drying time of the application is on the order of 3 to 5 hours depending upon temperatures and humidty.

Since most materials for duct construction are required to meet NFPA (National Fire Protection Association) 90A fire codes, Flex Seal has been engineered to surpass any and all fire/smoke requirements in the US or foreign countries.  ASTM tests show Flex Seal to have a Flame spread of zero, insuring full compliance with codes.

We recommend delaminated or heavily contaminated insulation be removed and replaced, and then recoated with Flex Seal.

Existing fiberglass insulation that still has its integrity and is not heavily contaminated should be coated to insure cleanabilty and prevention of fiberglass emissions.

What are your experiences, please let us know in the comment section below.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.

Filed under: Ductwork, Walls and Insulation, Technical Corner | Tagged: cleaning and coating insulation, coating duct work, Ductile, energy and cost reduction, fiberglass insulation, Flex Seal, hvac preventive products, hvac system maintenance, insulation coatings, insulation contamination | Leave a Comment »

Insulation is frequently applied to the internal enclosure of an HVAC air-handling unit (AHU) as well as air duct  interiors.   The majority of insulation found in use is of fiberglass construction.   The purpose of insulation is two-fold:  retaining heat or cold within the system and addressing acoustic concerns.

Of course, retaining heat or cold is of vital importance.   Loss of energy through the AHU enclosure or ductwork that is transporting the conditioned air means higher costs of operating the HVAC system.  Proper insulation helps keep these costs under control.  Indeed, if it were not for insulation, the size of HVAC units would have to be increased to take  energy losses into account.

Adequate interior insulation has also been shown to reduce the noise levels which otherwise might travel down the sheet metal ductwork and into occupied areas. Thus, the purpose of the insulation is two-fold – reducing energy losses and acoustic reduction.

While the insulation used in HVAC units is similar in character to that used to insulate houses, there is a vast difference in the operating conditions the insulation is exposed to.

Insulation placed on the interior of air handling units is subject to the normal vibrations when the system is turned on.  Glass fibers are bonded together using a polymeric glue mixture.  Over years of use, it is normal that fiberglass delaminates; probably this delimitation occurs due to vibrations, microbial attack on the glue, and temperature variations.  None the less, insulation that is over 20 years old may become delaminated.   A delaminated insulation loses its structural integrity and is likely to peel off in layers when handled.

Insulation efficiency of a delaminated fiberglass is not as great as properly formed material.

Older insulation, through loss of the bonding provided by the polymeric glue, can release fiberglass particles into the airstream, winding up in occupied room areas.  Often these particles are quite small, and can be breathed in by occupants.  Therefore, the presence of fiberglass particle emissions are looked upon as a negative.

Part two of this educational blog will be posting next week. Until then do not hesitate to list your comments or concerns below.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.

Filed under: Ductwork, Walls and Insulation, Technical Corner | Tagged: cleaning and coating insulation, coating duct work, Ductile, energy and cost reduction, fiberglass insulation, Flex Seal, hvac preventive products, hvac system maintenance, insulation coatings, insulation contamination | Leave a Comment »