I'm in the market for central air. I recently bought a 1,900 sq ft.
colonial with forced hot air for heat. I'm speaking with two reputable
local companies for the A/C service. Both have told me that my return
air is not adequate. I already knew this beforehand because I have a
single return duct running to the 1st floor (severely undersized) and
no return duct running to the 2nd floor. My question deals with how
each of these companies plans on remedying the situation.
Company A says they will branch off of the existing duct and add a new
return vent in another room on the 1st floor.
Company B says it is necessary to run a new duct up to the 2nd floor in
order to get a return on the 2nd floor. They say this is necessary for
air flow and air quality reasons.
Is it common to have only 1st floor returns in a multi-floor home?
Here in AZ the second floors become really warm in the summer. All of the
new homes that I looked at NOW have returns up and down. Problem is where do
you put the stat? If it is up stairs it will cool the bottom floor to a
lower temp than set. If on the bottom the top floor becomes slightly warmer.
I would want a return on the second floor. If your in a dusty dirty climate.
I would consider asking for a larger than normal return. That way when you
put in the super filters the static pressure is not so high as to lower the
air output. I have been told that tube grills have less static resistance
than the stamped ones.
Who ever does the job the closer the new return is to the unit the better
air flow you will get.
Im a home owner on my AC add on I had no second foor return, several
companies told me without the upstairs return it will not work well heat
will pool at the ceilings. I added one with the AC it operates well.
Whoever you get a load calculation needs to be done in writing , it is
to easy for them to oversize you leaving you to humid in summer. I dont
think the guy that wants a second first floor return is worth talking
If the home is over 2000SF by code in most areas, its required to have two
anyway....at 1900...its close enough to justify one anyway.
Without seeing your situation, and offering an opinion, this is the way to
On ANY multi level home we install systems in, each floor gets at least ONE
return, sized properly and ran to allow for proper circulation.
If the home requires more than 2.5 tons of cooling, we normally suggest two
sep systems as well, since that is the ultimate in comfort for most, and
when sized correctly, can be cheaper to run long term than a single system.
Where do they plan on mounting the thermostat? Any zone controls?
Most builders want CHEAP, and they want it NOW.
Most will go with the cheapest installers they can find, and many companies
will lower their rates to get that work, and in order to do that, you lose
Just checking about the zoning.
The company that suggested an upper level return is on the right track.
Without seeing what you have, its impossible to tell you if 3 tons is
enough. Have either, or both companies ran what is called a manual J? or in
teh case of a heat pump, a manual T?
If so, what about the manual D? A D must be ran to insure proper airflow,
and duct sizing, for the supply and return side.
It is possible, that company 1 hasnt done this..its possible company 2 hasnt
insist on this being done, or keep shopping.
Just a slight addition here...not a flame.
Even if the return is farther than one would like, sizing in this case can
Closer it is, to a point, you can use a smaller duct...TO A POINT. The
farther is it is, velocity and flow will come into serious play, and here is
where a manual D will save the day.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.