A duct board is a common form of heating and air conditioning insulation made out of fiberglass and a thin layer of foil. Each board typically is 1 to 2 inches (2.54 to 5.08 cm) thick, and several boards can be assembled together to help airflow and maintain temperature. Among its many benefits include its lightweight construction and durability.
Each duct board is primarily constructed from two layers to ensure efficient flow and protection from the outside elements. The bulk of each board is comprised of thousands of strings of fiberglass pressed into a flat sheet intended to face the airflow side of ventilations. The backside of each board is made of a thin foil layer that is airtight.
The fiberglass in a duct board serves primarily as an insulation barrier for the air passing through the duct. No matter if the temperature outside the duct is warmer or colder, its internal airstream will maintain its temperature more consistently than metal duct work. Many duct boards have their fiberglass treated to also help prevent the spread of mold and fungus through its hardware.
The metallic foil side of a duct board serves as a vapor barrier. Wetness can be harmful to the fiberglass and can lead to costly replacement. This layer protects moisture from being trapped within the fibers.
Many consider vent installation with duct boards to be simpler than traditional systems for many reasons. The most obvious reason is its lightweight construction. Where metal pieces of traditional ductwork might be bulky and awkward to carry, duct boards come several to a box and can be easily carried by a single, able-bodied worker. Fast installation is another trait of of duct boards. A series of boards can be assembled with very little hardware beyond a measuring tape, cutting knife, duct tape and staple gun.
An often overlooked benefit to a duct board is its noise-reducing qualities. HVAC systems produce a great deal of sound, whether blowing warm or cool air, and the fiberglass layer of duct boards muffles the noises coming from the source much the way recording studios are soundproofed with fiberglass insulation. Another way they prevent noise is that duct boards do not produce a booming or popping sound, which traditional sheet metal ducts make when they expand and contract.
A duct board is a versatile part of any heating and cooling system. Its light weight and simple assembly make it a popular choice for HVAC workers. Its ability to control noise benefits people who live and work around ducts.
By Patrick Wensink