How To Insulate Around A Attic Furnace

Plan to pull up the flooring and layer new insulation on top of the old.

How to insulate around a attic furnace.

Then use fire rated caulk to seal the gap btw the sheet metal and flue and then the sheet metal to the attic floor. Check the speed of the blower motor on the furnace. Rigid foam insulation is attached to the walls with adhesive and to the. Cut enough aluminum flashing from the roll to wrap around the vent pipe with an extra 6 inches to spare.

But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. This puts the furnace in at least semi conditioned space. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct.

If the furnace is a fuel burning one be sure you provide air for combustion. Cut 1 inch deep slots a few inches apart along the top side. Because the simplest and cheapest way to insulate an attic is to add material to the floor. Bend these newly cut tabs in.

Most often the attic is sealed by installing spray foam insulation at the roofline thus bringing the attic inside the building enclosure and turning it into conditioned space directly or indirectly. You can build a small enclosure around the furnace with rigid foam insulation then pick up the insulation on the ceiling inside the enclosure. Now cut 2 inch deep slots. Suggest that the hvac air handler in the attic be enclosed in a well insulated equipment room r 19 or greater and all the ductwork in the attic should be insulated to r 19 or greater not r 4 3.

Unwrap the flashing from the vent pipe so you can work with it. If necessary switch the wires to reduce the blower to its lowest speed. Cut two flat sheets of aluminum flashing that are 14 inches long and narrow enough to fit between the ceiling joists around the flue. It is more costly to have your conditioned space heating cooling air running through a poorly insulated hvac system in the cold hot attic.

Heating cooling a while back i wrote about the incompatibility of putting an atmospheric combustion furnace in a sealed attic. Nail them both on the attic floor so they butt up against the flue. This will stop the air from getting a free ride along the chase and heating your attic.