The Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA) has published the fourth edition of its HVAC Duct Systems Inspection Guide.

Learn how HVAC systems can contribute to dust in your home and discover effective solutions to reduce it. Explore common ...

The ANSI-recognized national standard for residential HVAC duct design will help you design a duct ... and new equivalent length values for flex duct junction boxes. Manual D, from the Air ...