new trane hvac system (how big should return be)

t_j_ames2003December 12, 2006

I'm not an HVAC expert but I've recently had an HVAC system installed in my row home (Trane TUD080R furnace and 2TTX4030 condenser). The job is near complete and by chance I had a guy in there the other day not associated with the company who installed it who told me the return for the unit is too small. He also mentioned that the thermostat should be on the first floor and not the second (top) floor. He said the way it is not, the coils will freeze because the unit can't draw enough from the return.

Is there any way I can find out how big the return should be?

Thank you for reporting this comment. Undo
klabaach

Duct you Later...

    Bookmark   December 12, 2006 at 12:29PM
Thank you for reporting this comment. Undo
fluffybunnysui

I generally go by a minimum of 144 sq.in. per ton of cooling.
*Note* Your return can never be too big but it can be too small.

    Bookmark   December 12, 2006 at 1:08PM
Thank you for reporting this comment. Undo
jca1

Don't know but I have a 3-ton HP with two 20"x20" returns, a 2 ton HP upstairs with one 20"x30" return.

    Bookmark   December 14, 2006 at 7:25PM
Thank you for reporting this comment. Undo
vstech

Um, that's a lot of return filter area...
John

    Bookmark   December 14, 2006 at 7:29PM
Thank you for reporting this comment. Undo
klabaach

" *Note* Your return can never be too big but it can be too small. "

Ughh.. If your return air is too big, it wont flow back to the unit properly and it can ice up the unit.
Plus your not pulling back the stale air into the system to cool it in the area you want to pull from. Your temp readings in that area will take way longer to cool or heat in the winter time.

    Bookmark   December 14, 2006 at 10:07PM
Thank you for reporting this comment. Undo
fluffybunnysui

I have never ever in my life heard that happening from the return air being to big. How can having too much air available for the return freeze up your unit??

    Bookmark   December 15, 2006 at 8:54AM
Thank you for reporting this comment. Undo
bama_dude

144 sq in per ton is a minimum by code where I am located.I normally oversize to around 180 sq in per ton.You can not freeze up a system with to large of a return.Altough static pressure must be considered when sizing a return.Some systems have no return duct at all.

    Bookmark   December 15, 2006 at 9:30PM
Thank you for reporting this comment. Undo
udarrell_2007

There is a lot to proper ductwork design.
Below is a link to some basic ductwork design info.
udarrell _ 2007

Here is a link that might be useful: udarrell.com

    Bookmark   August 12, 2007 at 12:47PM
Sign Up to comment
More Discussions
Floor Air Register and ductwork
In recently doing light cleaning on air registers in...
Char Holdenried
Need help with my Heat Pump
I have a 2 ton carrier air handler that is 410-A compatible....
Jason Johnson
I Like the Forum Changes
IMO; this new forum setup is an improvement...
udarrell
HVAC question
I live near Charlotte NC and have a new Bryant Hybrid...
gtodd1966
auxiliary heat vs. emergency heat
Greetings, I have a Bryan Evoltion Control heat pump...
decadent
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™