1 Trade Skills HVACR116 Fiberglass Duct Board and Insulation Material

2 Fiberglass Duct Board For nearly 50 years, fiberglass insulation has been used as a component of air duct systems to maintain comfort and IAQ. HVAC fiberglass insulation meets four requirements of a duct system: Temperature control — Delivering heated or cooled air at the temperature level best suited to building needs. Acoustical control — Absorbing noise generated by air-handling equipment and by air moving through ducts Condensation control — Preventing condensation that could damage insulation and other HVAC system components or possibly lead to microbial growth Energy conservation — Reducing HVAC system operating costs and energy use by lowering heat loss or gain through the air duct wall.

3 Fiberglass Duct Insulation Types Although new materials are introduced from time to time to serve as new HVAC duct system materials, the fact is that nearly all duct insulation products continue to use fiberglass technology, for reasons of safety, cost effectiveness, and performance. There are four basic types of HVAC fiberglass insulation products: –duct liner –duct wrap –duct board –and flexible ducts. Although new materials are introduced from time to time to serve as new HVAC duct system materials, the fact is that nearly all duct insulation products continue to use fiberglass technology, for reasons of safety, cost effectiveness, and performance. There are four basic types of HVAC fiberglass insulation products: –duct liner –duct wrap –duct board –and flexible ducts.

4 Duct liner. Used in the interior of sheet metal ducts, fiberglass duct liner products come as flexible blankets or rigid boards of fiberglass insulation. Liners are offered in a variety of thicknesses and density combinations, from 1/2 to 2 inches. Duct liner. Used in the interior of sheet metal ducts, fiberglass duct liner products come as flexible blankets or rigid boards of fiberglass insulation. Liners are offered in a variety of thicknesses and density combinations, from 1/2 to 2 inches.

5 Duct wrap. Fiberglass duct wrap is applied to the outside of sheet metal duct. It is a blanket-type thermal insulation composed of glass fibers bonded together with a thermosetting resin. Duct wrap can be used for both round and rectangular duct. It normally has a vapor-retardant facing of foil scrim kraft (FSK) or vinyl. Duct wrap. Fiberglass duct wrap is applied to the outside of sheet metal duct. It is a blanket-type thermal insulation composed of glass fibers bonded together with a thermosetting resin. Duct wrap can be used for both round and rectangular duct. It normally has a vapor-retardant facing of foil scrim kraft (FSK) or vinyl.

6 Duct board. Fiberglass ducts are fabricated from 1-, 1-1/2-, or 2-inch-thick boards. The board consists of insulation materials made from resin- bonded inorganic glass fibers. The outside surface of the board has manufacturer- applied reinforced aluminum/FSK laminate facing that serves as an air barrier and water vapor retardant.

7 Flexible ducts. Flexible fiberglass insulated ducts consist of a spiral-wire- reinforced inner air core, wrapped with fiberglass insulation, and jacketed with a vapor-retardant reinforced foil or plastic film. These ducts provide an efficient, economical way to connect trunk ducts and room diffusers or registers.

8 Fiberglass Duct Board Fiberglass duct board systems can be fabricated in either a shop or on the jobsite. Once cut to the required size, fiberglass duct sections are first stapled closed. The next step is sealing joints, using either UL-listed pressure- sensitive foil tape, UL-listed heat-activated aluminum foil tape, or UL-listed fiberglass fabric or mastic when the duct system is part of a fire-rated assembly. Fiberglass duct board systems can be fabricated in either a shop or on the jobsite. Once cut to the required size, fiberglass duct sections are first stapled closed. The next step is sealing joints, using either UL-listed pressure- sensitive foil tape, UL-listed heat-activated aluminum foil tape, or UL-listed fiberglass fabric or mastic when the duct system is part of a fire-rated assembly.

9 Fiberglass Duct Board This machine is used to cut the grooves into the duct board. By having grooves cut in the duct board is easier to form into duct work.

10 Fiberglass Duct Insulation And IAQ In 1994, OSHA issued the first federal proposal for comprehensive regulation of indoor air quality. –It addressed the 30 percent of all “non-industrial work environments” believed to have IAQ problems. OSHA outlined a detailed inspection and compliance program of maintenance, ventilation, relative humidity, and carbon dioxide control. –Its goal was to significantly reduce the incidence of “sick building syndrome” and the bacterial infection known as Legionnaire’s Disease. In 1994, OSHA issued the first federal proposal for comprehensive regulation of indoor air quality. –It addressed the 30 percent of all “non-industrial work environments” believed to have IAQ problems. OSHA outlined a detailed inspection and compliance program of maintenance, ventilation, relative humidity, and carbon dioxide control. –Its goal was to significantly reduce the incidence of “sick building syndrome” and the bacterial infection known as Legionnaire’s Disease.

11 Independent studies have found there is no link between poor IAQ and well-maintained fiberglass HVAC insulation. Most fiberglass insulation ductwork provides the following benefits: –Can be cleaned: The duct board and liner used in HVAC systems have surfaces that can be cleaned with commonly available duct cleaning equipment. –Has antimicrobial agents: The airstream surface of many duct liner and duct board products contains an EPA-registered antimicrobial agent in order to reduce the potential of microbial growth that may affect the product. Independent studies have found there is no link between poor IAQ and well-maintained fiberglass HVAC insulation. Most fiberglass insulation ductwork provides the following benefits: –Can be cleaned: The duct board and liner used in HVAC systems have surfaces that can be cleaned with commonly available duct cleaning equipment. –Has antimicrobial agents: The airstream surface of many duct liner and duct board products contains an EPA-registered antimicrobial agent in order to reduce the potential of microbial growth that may affect the product.

12 Does not erode: Fiberglass duct board and duct liner are manufactured and tested to handle air conveyance well above normal operating conditions. They will not degrade when exposed to streams of hot or cold air and they do not allow glass fiber to enter the airstream. Has moisture-repellent properties: Some manufacturers, such as CertainTeed, now feature a moisture-repellent airstream surface enhancement that is significantly more moisture-resistant than previous type of duct insulation. –The feature was developed for contractors who want to alleviate any concerns about moisture that may enter a duct system due to improperly sealed duct joints or poorly installed and maintained duct systems. Does not erode: Fiberglass duct board and duct liner are manufactured and tested to handle air conveyance well above normal operating conditions. They will not degrade when exposed to streams of hot or cold air and they do not allow glass fiber to enter the airstream. Has moisture-repellent properties: Some manufacturers, such as CertainTeed, now feature a moisture-repellent airstream surface enhancement that is significantly more moisture-resistant than previous type of duct insulation. –The feature was developed for contractors who want to alleviate any concerns about moisture that may enter a duct system due to improperly sealed duct joints or poorly installed and maintained duct systems.

13 The best way to ensure that an HVAC system continues to provide quiet air delivery and occupant comfort in a cost-effective manner is to follow a regular maintenance schedule.