When the combustion air duct is connected directly to the return plenum for a furnace, the blower fan on the furnace pulls outdoor air in to the return plenum. To supply this air to the furnace room, ...

While recently eating dinner with my colleague Paul Wieboldt, we started talking about the common defects found in many duct systems today. As we listed the various duct system flaws typically ...

[Editor’s note: When we last visited with lead installer John and his helper Charlie (The NEWS, March 5, 2007), they had just learned the hard way that there’s a lot more to sealing ducts than just ...