Plug all open joist spaces under insulated side walls.
Air space along side of chimney in attic.
Fold the bag over and stuff it into the joist space under the wall.
Ideally both metal and masonry chimneys should be airsealed for energy conservation purposes air leakage and to stop house moisture getting to the attic with the escaping house air.
Right or wrong that s just the way they did it up until 75 to 100 years or so ago.
Measure the four sides of the chimney where it goes through the ceiling framing and add up the.
It was common practice to offset the chimney on one side of a wall say the kitchen for a kitchen wood stove and leave the living room wall flush.
Access the attic through a crawl space in the ceiling using a stepladder or use or the attic stairs.
Construct a sheet metal shield around combustion flues to maintain 3 inches of clearance between the flue and attic insulation.
Combustible material shall be permitted to abut the masonry chimney walls provided there is a minimum of 12 inches to the inside surface of the flue liner or in the case of a fireplace 12 inches from the inside surface of the firebox.
It s easy to see your point about eliminating ductwork from the attic.
Make the air move over as long a path as possible.
O is air conditioning the 1st floor effective with floor venting if i run ductwork in the basement.
Hot air rises so locate an attic vent at the highest part of your attic.
Try to draw in air from cooler outside areas but note that doing so may not be practical due to prevailing winds.
A two room addition on the 1st floor has limited attic space and a 4 crawl space.
With the metal types check with the manufacturer as some are still tested with the loose attic insulation shield firestops and should be left as is.
To air seal around combustion flues use fire rated caulk and ul rated collars or sheet metal cut to fit and sealed with fire rated caulk while maintaining proper clearance between flue and combustible materials.
However i have two questions if i want to centrally air condition my entire house.
Opening all the windows at the same time doesn t do much either.
For exterior chimneys a 1 inch minimum air space must be maintained between the chimney and combustibles.
Windows a few feet apart don t do much.