Air Return From Finished Attic

I finished our basement with a cold air return located near the floor.

Air return from finished attic.

This isolates the attic from the rest of the home which means the attic isn t part of the conditioned envelope. Essentially that allows the warm air to circulate better. Open floor trusses used as return air plenums can draw air from any place connected to that floor. Most codes require a specified minimum amount of headroom and it s tough to meet this requirement when insulating a finished attic especially since most.

It s much better to place it low to suck out the cold stratified air. That s measured after you finish the ceiling if you don t have enough height you ll have to raise the roof line and that adds a lot to your construction costs. If you had no return air in your room you would create a positive pressure. That is why you need a cold air return image 1.

Supply air from furnaces and air conditioners should be on outside walls. At 21c i d guess you have a lot of leaks on the return side. If you leave a cold air return opening on the ceiling. Essentially you re bringing the attic into the rest of the house.

It is close to the furnace and actually on an adjacent wall. The basement is no exception to the rule. Nail a piece of sheet metal onto the back of a stud cavity. To meet all three goals insulating your finished attic ventilating the roof and maximizing headroom use a combination of dense batt insulation rigid foam sheeting and air chutes.

For the system to work you have to re circulate the air back to the furnace. Air handler platforms used as return air plenums can draw air from vented attics and crawlspaces through other connected framing cavities. That would then reduce the flow of conditioned air to that space. I also included a fresh air return with motorized damper to bring in outside air.

A return air temp b outside air temp c airflow across evaporator coil d return air leaks from attic if you measure supply and return temperatures at the grille and at the air handler you can get an good idea of where your biggest losses are occurring. One of the most effective ways to convert your attic space into a spare bedroom is to remove the insulation from the floor and add insulation to the attic ceiling. This pulls the air across your body. If the supply ducts are in the floor then the return air should be located up high.

First check for head clearance. Building codes vary by location but most require at least a 7 foot clearance for attic expansions.