This may be asked all the time, so forgive me if its a repeat question, but here goes:
I am having hardwood floors refinished in my 1930’s 1-1/2 story house. My first floor is about 900 sq ft, and has 3 return air vents (with 1 more upstairs). The floor refinisher suggested I could remove one of these vents (in the hallway) and patch in new flooring, stating that return vents were often ‘overdone’ in old houses.
This makes sense to me, as the blower in the 1930’s furnace probably would have been less powerful, and need more return vents to lower static pressure. (Just my reasoning here, could be wrong).
I’d like to get rid of the return vent, but only if it is truly unnecessary and won’t affect heating/cooling. I tried using a mercury manometer on the return plenum of the furnace, but it wouldn’t register (i.e., too low of pressure to register).
I know there are probably a ton more variables involved, but can someone help me out with some guidelines as to how one would calculate if this particular return vent is superfluous?
My current test is empirical – I put a sheet of plywood over the return vent, and things seem to be going ok.
Thanks in advance,