I have a 3.5 ton unit in a 1500 sq ft under air home. Insulation is not the best (R13 ish with almost 20% of the home being under a 'flat' roof), and it's located in S. Florida. It's a bit oversized still I believe.
What appears to have happened was this unit was upgraded with a new addition to the home (275 sq ft room with the flat roof), from a 2.5 ton prior.
It's a split system with the air handler right on top of the old return.
The return takes a 18.5 x 18.5" filter and has a 14" duct going about 24 inches to the air handler. The air handler sits on one part of the duct knocking is down to about a 12" opening. I can't raise the unit higher than it is.
Cooling is good and the return is not too loud. My a/c runs 7-9 hours a day at 6am-8am 78, ->4pm 85, -> 12am 78, ->6am at 82 degrees.
Still I am thinking if I went to a 18-20" duct and expanded the return size to 18.5 x 24 or so it would improve cooling a bit. By expanding the return/air box I think I could get the duct from being right under the unit. At the same time it will fit between the existing beams and should be a pretty transparent install into my ceiling.
My second repair on this will be to put a second return in the office adjacent to the living room with it's own filter.
Is there any good how-to's on building a return box/plenium?
I am pretty handy and this all came up when an A/C guy I hired to fix a dripping pan brought up everything as a problem except fixing it. I was able to go in the attic, pull the side panel off the unit and see a coil to drain pan hose visibly with a clump of algae in the bottom of it. I popped it off and ton of water came out. The pan was nice and clean.
Thanks
Å
What appears to have happened was this unit was upgraded with a new addition to the home (275 sq ft room with the flat roof), from a 2.5 ton prior.
It's a split system with the air handler right on top of the old return.
The return takes a 18.5 x 18.5" filter and has a 14" duct going about 24 inches to the air handler. The air handler sits on one part of the duct knocking is down to about a 12" opening. I can't raise the unit higher than it is.
Cooling is good and the return is not too loud. My a/c runs 7-9 hours a day at 6am-8am 78, ->4pm 85, -> 12am 78, ->6am at 82 degrees.
Still I am thinking if I went to a 18-20" duct and expanded the return size to 18.5 x 24 or so it would improve cooling a bit. By expanding the return/air box I think I could get the duct from being right under the unit. At the same time it will fit between the existing beams and should be a pretty transparent install into my ceiling.
My second repair on this will be to put a second return in the office adjacent to the living room with it's own filter.
Is there any good how-to's on building a return box/plenium?
I am pretty handy and this all came up when an A/C guy I hired to fix a dripping pan brought up everything as a problem except fixing it. I was able to go in the attic, pull the side panel off the unit and see a coil to drain pan hose visibly with a clump of algae in the bottom of it. I popped it off and ton of water came out. The pan was nice and clean.
Thanks
Å