Return Air Question

[mcex]

How does return air draw from the upstairs in a 2-story house when the return ducts in the basement are formed with the floor joists and sheet metal that has numerous small gaps that are not sealed off?

It seems to me that the air will take the path of least resistance which would be air from the basement.

Why are these joints typically not sealed?

[ryan_the_furnace_guy]

Originally posted by mcex
Why are these joints typically not sealed?

It is this way because a lot of new construction guys simply don't do it. And yes, you are right, you will be pulling return air from the basement. I would seal it all off.

[tinknocker service tech]

o get some chalk and seal up what you can this will give you less to worry about. will also help a little with return upstairs.

[dash]

Be aware there could be other ducts leaks that you can't se so easily.

Consider having the ducts tested and sealed if needed.

Check http://www.aeroseal.com

[mid carolina]

If you have leaks that you can easily see, I hate to think what might be hidden,

go get a gallon of duct mastic and a couple of brushes and start sealing everything.

Just to be clear, you have a basement, main floor, and second floor on one system?

[mcex]

Yes, it is all on one system. About 1000sf in basement and 2300sf between main and 2nd floor.