Fire dampers are dampers which are forced to close in the event of a fire. There are different kinds of fire dampers, and they are classified according to the following factors: how they are actuated or forced to close; the physical constraints of their installation; and the fire rating of the ceiling, floor, or wall being penetrated.

Fibrous-glass ducts are constructed from fiberglass board and are available in several variations. Variations include, but are not limited to: standard duct board, medium high velocity duct board, and environmentally pure duct board.

Air distribution refers to the distribution of air to and from conditioned spaces within a building. An air distribution system includes all sub-components, such as fans, filters, dampers, ductwork, etc. Air distribution systems come in a variety of material types, for example, fiberglass and galvanized metal. In fact, many different kinds of ducts may be found in a single air distribution system.

There are three purposes for duct insulation: to retard the flow of heat, to reduce the amount of duct-transmitted sound, and/or to act as a vapor barrier. To retard the flow of heat, ducts may be insulated on the inside with duct liner, or on the outside with duct wrap. To reduce the amount of duct-transmitted sound, a product called sound liner may be used. As a vapor barrier, ducts are usually wrapped with a vapor sealable material such as foil or plastic.

Expansion fittings and loops may be required in any piping system which contains fluids with temperatures elevated above normal room temperature. Most piping in commercial systems is comprised of metals; common piping materials include copper, black iron, steel and stainless steel. When heat is applied to metal, it undergoes thermal expansion. The rate of expansion depends upon the metal and the heat being applied. In piping, there are two directions in which thermally expansion can take place: circumferential and longitudinal. Circumferential lengthening is negligible and therefore is not a concern. But longitudinal expansion, depending on how long a pipe is run, can be several inches or more. Because piping is rigid, if the change in length is not provided for via expansion fittings or loops, the pipes can shear the connections and cause ruptures. Different metals expand at different rates, but all expand with the addition of heat. Expansion fittings and loops allow the piping to expand without failure.

This topic covers information related to dehumidifiers installed as part of a HVAC system during construction. Dehumidifiers remove moisture by condensing water vapors to a liquid. Water is collected, evaporates or drains to a specified location.

Humidity control equipment has the ability to add moisture or humidify to a space or remove moisture and dehumidify a space. Humidifiers introduce moisture to distributed air from centralized HVAC equipment, using evaporation, mist or steam.

This topic covers information related to radiators installed during construction. Radiators can be single or double pipe systems that are used in conjunction with a boiler. Water or steam is circulated through the pipes and radiates heat through a structure.

This topic covers information related to convection heating and cooling units installed during construction. Convection heating and cooling units control air temperature using electric, steam or water. The appliance conditions a space using either convection, mechanical fan, induction or radiation.

This topic covers information related to computer room air conditioners installed during construction. Computer room air conditioners are specialized equipment that provide cool air and humidity control to computer control and equipment rooms.

This topic covers information related to room air conditioners installed during construction or on an as needed basis. Room air conditioners provide chilled air to a space by removing heat and humidity during a refrigeration cycle. They can be temporary or fixed appliances installed through wall or within a building opening.

This topic covers information related to decentralized HVAC equipment installed during construction. Decentralized HVAC equipment are stand alone automated units designed to provide heating and/or cooling to a specific room or zone within a structure.