Return Air Base Height

tomjo

I just had my furnace and AC replaced. New furnace is 110,000 BTU Carrier 58ctw-110. An 8 inch return air base was supposed to be installed but wrong instructions were given to the installers and they only put in 4 inches. The HVAC company owner is now telling me an extra 4 inches won't make much difference, but it will mean 24 inch filters instead of 20 inch filters since he can only cut a 16 inch hole in the side of the furnace. And 24 inch filters are harder to find. Should I make him fix his mistake?

EBEBRATT-Ed

It's hard to visualize what you mean but I would say your installer is trying to cheap out on the correct fix. How many air filters and what size/ How many ton of air conditioning?

tomjo

One air filter, 4x20x25. 3.5 ton AC.

Harvey Ramer

A static pressure reading across the furnace will tell you if it is good or no good.

If it is no good, it is in your best interest to have it remedied or it will be a constant headache and could cost a bunch of money due to equipment failures.

EBEBRATT-Ed

I agree with @Harvey Ramer

Tinman

I'd bet the farm you'll have problems with that. I would have installed the air cleaner horizontally in the return air drop with a change fitting above and below it, and then drop down into a bottom box at least 10" high.

geenyus21

It'll be fine. The 8 inch will restrict tooth anyway

geenyus21

The 8 inch will restrict too much anyway