Flex duct manufacturers now regularly use fiber-laced and silver-coated jackets, which hold up much better than older materials. Silver coatings hold up well in the heat, whereas gray and black vinyl ...

And flex duct manufacturers do a good job of providing installation information." A Michigan contractor lists one more use for flex duct - moving make-up air. "We don't use flex duct much except for ...

Technicians measure duct runs using a manual called ACCA Manual D based on many factors. Leave sizing to the pros! Flexible or Rigid Straight “trunk lines” off your furnace/heat pump use rigid metal ...

These flexible, insulated feeder ducts are only 2 inches to 3 inches in inner diameter. In diameter, and air moves through them at about 1,500 feet per minute (fpm) ...

If the duct runs are short enough and the performance of the system wouldn't suffer, it is possible to snake smaller sized flexible ducts through existing ductwork.

For more information on combustion air supply ducts and purchasing a furnace or air conditioner, contact the Minnesota Energy Office at 651-296-5175 or 1-800-657-3710.