buffalobill wrote:
more at:
http://www.buildingscience.com/resou...al/default.htm

Alex wrote:
Hello,

My wife and I are planning on enclosing our garage next summer, and
this will bring our 1600 sq house up to about 2100 sq. We planned on
upgrading the 23 year old central air/heat system in the house then,
but a couple of weeks ago the unit died and needs replacing now.

We currently have a 3 ton system but in anticipation of convering the
garage in we're upgrading to a 4 ton, 15 SEER system. I know if the
system is too large it won't remove enough humidity from the house and
mold can set in, plus shutting on and off alot is bad for the system,
however will us having the system in place for 6-8 months hurt it like
this? Winter is here, and I doubt we'll be using the air conditioner
much until next March or April, just the heat if that, but just curious
of what we need to look out for.

We live in Central Texas where the humidity generally stays around 50%
or lower, and only rarely jumps up to 65% or higher. I figure worst
case we can get a stand alone dehumidifier if humidity does become a
problem. Will this help?

Just curious on what others think about this. Thanks for any input ...

Alex



There's no harm in having an oversize unit for a year until you do the
addition. The bigger question is, did they do a manual J to figure
out what size you needed? 4 tons sounds like a hell of a lot of
capacity for 2100 sq ft. average construction house. Also, they should
have verified that they can get proper ducting to the new area as well,
figured out how it's gonna be done, etc, so that it can be integrated
in. I would have made sure of that, so there are no surprises later on.