The National Air Duct Cleaners Association (NADCA); also known as the HVAC Inspection, Cleaning, and Restoration Association; today announces the publication of a white paper on methods of inspecting ...

NEC cabling installation requirements are straightforward, but markings and new offerings may create confusion. You're not alone if markings and listings are making your plenum cabling selection a ...

As many contractors attest, a supply air plenum is a sheet metal box attached to a furnace or air handler’s outlet and is used as a central manifold connector for other ductwork. As the air blows from ...

Class 2 and Class 3 plenum cables listed as suitable for use in ducts, plenums, and other spaces used for environmental air shall be Type _____. The correct answer is: a) CL2P and CL3P Article 725 ...