A/C intake question...

[Pewterpower]

Not sure where to post this question, but I'm sure someone here will know....
I have a 2 story house, with the air handler, and main intake, upstairs.
Downstairs, the only intake is in a bedroom and it is only a small 12x12 opening.
This is the room that we gave to my mother. The trouble is that she always keeps her slider open (even when it's 90* outside). I've weatherstipped her bedroom door (go ahead, laugh....) and I change the filter in that intake twice as often as the main one cuz of dust, etc....
But what I can't stop is all the humidity that is being pulled into that intake.

Sooooooooo...........

Can I just block it off altogether? At this point, I think it actually does more harm, than good. My thoughts are, YES, BLOCK IT OFF, but I thought I'd throw it out there for you guys to consider.

[jadnashua]

If you don't get enough air flow over the cooling coils, it will ice up and even if that doesn't happen, you might exceed the design load on the blower motor. You'd have to do some calculations on cubic feet per minute the fan is drawing (the air handler may have an adjustable fan - check out the spec sheet), the a/c load, and what volume and at what backpressure you can get from the other return duct. Problem is, if you aren't careful, you'll be sucking outside air through all of the cracks in the house and putting a bigger load on the fan than design - wearing things out quicker.

[Dchall_San_Antonio]

Try bocking it off and see what happens. You might get intolerable whisting in the other air return grille. But keep an eye out for icing as mentioned above. You probably won't get it but you'll never know if you don't look for it.

For a longer term solution you could reroute the air return to the hallway outside her room.

[Pewterpower]

Rerouting it is what I have been considering. Of course the easiest place to move it to, the wife says NOO!!!!!!! It would not look good on her beautiful living room wall.
I might just try blocking it and monitoring it daily. Just for the heck of it.
The main intake is 20 X 30 (approx 4 sq ft) and I would be blocking a 12 X 12 (1 sq ft) intake.
So I would be reducing a total area of 5 sq ft, down to 4 sq ft. That's a reduction of 20% total area. That doesn't sound tooooooooooo dangerous, does it?