Hi-

I posted this question in the heating and air condition section, but no one replied to it. Perhaps someone in this section can help me?

My village requires cold air returns for all rooms (except the bathroom) of the basement I am finishing. I have a house built in 2002, which has central air and heat, fed from a gas fired furnace and an air conditioning unit sitting in my back yard. There are 8" x 20" rectangular ducts feeding into and out of my furnace (one air return, 2 exit ducts for distribution) that provide for a cold air return into the furnace, and as a pathway out of the furnace to provide hot or cold air as necessary to the distribution system. Large 8" metal ducts feed the grates in my house that heat/cool the room. Cold air returns for my existing rooms are a channel made by the studs that make up the wall. On some of the overhead basement joists, a sheet of metal is used to enclose the joists to form a cold air return channel.

So, I'm finishing my basement and will have 3 rooms that need cold air returns. What can I do to meet the requirement? Do I just go to Home Depot, buy come ducting, cut into the existing cold air returns, connect it all up, and that will meet code? Do cold air returns have to be a certain size relative to the room? Can someone point me in the right direction?

Thanks,
Steve

 

Yes, you can tape into your existing ductwork. However, you cannot cut into your floor joists to do this. I would possibly think along the lines of laying out my basement rooms so that the ductwork goes through each room if possible. Then you can just tap into it with a vent. Just some food for thought.