Air Conditioning - return line for separate room
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raharold
02-13-04, 02:49 PM
I recently had my central air replaced with a brand new unit. As part of the installation I had the installer run a line to my detached utility room (attached via open walkway and attic). The unit was sized assuming this space so the installer recommeded that I leave the vent open all the time so the unit has enough flow. Just the other day I started thinking about it and realized I don't have a return path for the air. Will this signifcantly degrade the efficiency of the unit? Should I run a return line or not worry about it?
Ed Imeduc
02-13-04, 04:11 PM
Where are the other returns? If you have enough returns now and this room is, open back into the home see how it does first. If it dont yes you have to put a return in . Its just like blowing up a balloon You can only put so much air in it and if you want more you have to let some out. Will the heat and AC to the room be open all the time.And yes you need one if the unit you put in is bigger than the old one for that room;) ED
raharold
02-14-04, 02:22 AM
The only return is in the front of the house near the unit. The room in question is actually part of my detached garage. There is an open walkway between the house and the garage. The roof is extended over the walkway so the attics are connected. The A/C technician ran an 8" flex line from the manifold all the way thru the attic over the walkway and into the room. Should I just run a jumper from the room over the walkway to the back room of the house or a return all the way to the unit? Should I use flex line? If so, what size?
Thanks for your help.
Thanks for your help.
GregH
02-14-04, 05:53 AM
I find it surprising that a "Technician" would install an air supply with no way for the air to get back!
As Ed says you will only have airflow untill the room is pressurized or you open the door.
12" should do for a return and as long as the return for the whole house is adequate just installing it in the space is ok.
As Ed says you will only have airflow untill the room is pressurized or you open the door.
12" should do for a return and as long as the return for the whole house is adequate just installing it in the space is ok.
Pendragon
03-04-04, 11:07 PM
Just as importantly, all the air being pump out into that room, is being sucked back in to the house from the outside through every nook, cranny and crack it can find. Find a small window in the house while the a/c is running and crack it. I bet you'll find a good flow of air coming through it as the a/c tries to replace the air the home is losing to the unattached room.