During the summer months, the second story of my house is significantly
hotter than the lower levels. The house is filled with vaulted ceilings
throughout, and there is no attic.
We had air conditioning put in when we moved in last year, and we've
replaced the windows that get the afternoon sun. However, its still
regularly 5 to 10 degrees hotter upstairs. (I've tried closing the
registers downstairs, so that only the upper registers were working,
but what winds up happening then is the house NEVER gets cool
enough...the AC runs constantly. )
The cold air return for the central heating (and now cooling) for the
upstairs is located at the top of the stairs, but at the bottom of the
wall. So, even though its upstairs, the cold air return is at the
bottom of a 10 foot high wall. I have verified that the return is just
between two studs, and, as far as the wall is concerned, there is no
duct work - the studs act as a channel for the return air. (I imagine
that it hits duct work once it reachs the floor somewhere.)
I have a theory that putting ANOTHER return register at the TOP of the
wall would make a significant difference in the efficiency of our
cooling system during the summer months (provided that I can easily
close off the lower return register.) It just seems to me that having
a register as high as possible is more likely to recycle the hottest
air back into cold air.
How much improvement am I likely to see? Is this going to make a 1
degree difference, or is it likely to make a much more significant
change? I know that the house wasn't really designed with AC in mind so
the duct work on the upper levels isn't as big as it should be, but
shouldn't this change still make a significant difference?
I'd really like to know, since my wife and I would rather not put
another hole in the wall unless its worth it. The more detail on this
answer, the better, since we REALLY want to be educated about what
we're doing HVAC-wise.
On a side note, many of the (non vaulted ceiling) houses in our area
have whole house fans, that suck hot air into the attic, and then out
of a vent in the attic. I don't have an attic, since all of my
ceilings are open. Is it possible to put a whole house fan in that
performs the same purpose, but in a _vaulted_
ceiling? In other words,
one that just sucks the air right out of the house and out of a
(properly weatherproofed) hole in the roof?
Any other suggestions as to what we can do to make the temperatures
more even throughout the house? Any quick fixes that I'm missing?
- Thanks for all of your help,