Another HVAC question

madmax

My HVAC system is in the basement and whenever the AC or heat comes on it pulls my basement door on the main level closed. Why does it do that and is this a problem?
madmax

obieone

It means your system is 'out of balance', meaning, you have more supply, than return. The only way to fix it is by adding the CORRECT size ductwork.
If it's more than 1 story, you'd have to run a return plenum from the 1st/2nd/3rd flr. down to the basement.
Basically, a chaseway, common to all floors.

rpf65

+1 with obieone. Whats happening is your over pressurizing the area/room where doors close. Easiest fix is to add return air in those rooms. Will not be cheap, but usually 1 square foot of return air in any room experiencing this will work. Sometimes a little more is required. Call a company that has a good reputation, and not the cheapest one. They will usually evaluate a situation like this at no charge.

Polkie2009

Also make sure all your air vent(registers) in other rooms are open, no leaks in any plenum or ducts, and you don't have any closed doors on any of the other rooms?

madmax

Thanks for the input! I do have a bunch of closed doors, will first try opening all of them.

Leftplumma

Have you changed the return air filter lately??

4406bbl

madmax wrote: »

My HVAC system is in the basement and whenever the AC or heat comes on it pulls my basement door on the main level closed. Why does it do that and is this a problem?
madmax

When mine did that it was all from unsealed return duct joints, hard to believe they leak that much.