American gas association has certified the design of condensing furnaces for a minimum of 0 clearance from combustible materials with a single wall plastic vent pipe.
Clear attic furnace flue.
I try to always design in some slop in spacing around mechanical equipment.
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.
2015 irc m1305 recommends that the furnace have a level working space of at least 30 inches by 30 inches in the front of the appliance.
How to check for creosote.
The opening around a furnace or water heater flue is a major source of warm air into the attic photo 5.
Then use fire rated caulk to seal the gap btw the sheet metal and flue and then the sheet metal to the attic floor.
The vertical flue at the ceiling level is surrounded by and attached to a horizontal piece of open 1 2 x 1 2 metal mesh screen about 10 square.
Because the pipe gets hot building codes require 1 in.
Because the pipe gets hot building codes usually require 1 inch of clearance from metal flues 2 inches from masonry chimneys to any combustible material including insulation.
To check for creosote yourself first make sure there s no downdraft from the chimney.
You can reduce creosote buildup in your fireplace flue by providing adequate combustion air which will encourage a hot clean burning fire.
Wipe it clear with a rag or soft cloth and then replace the cap.
Municipalities may require a minimum of 30 clear inches in front of the furnace which can be accomplished in a small room if the door to the room opens in front of the furnace.
Furnace flues require special sealing techniques the opening around a furnace or water heater flue or chimney can be a major source of warm air moving in the attic.
See direct vents side wall vents for a complete table of recommended clearance distances from a direct vent gas appliance terminal to other building components or features.
From masonry chimneys to any combustible material including insulation.
Not much furnace experience around here that s just a heating coil on the end of the a c blower used for 7 8 weeks a year g.
Of clearance from class b flues 2 in.
While you are at it look around for all other duct chases in your attic.
The vent should always be clear.
The metal furnace flue extends vertically through the closet ceiling through the attic and roof.
Now i do have experience with technology change versus construction framing.
