Quote Originally Posted by Thardwick View Post
It's in a utility room and on a crawl space. We inspected EACH run and trunk... No, the boots at the floor aren't caulked and not every joint is taped but there are no holes in the ducts or runs. I know, not very specific sorry. We are a carrier dealer. However, with the location of the furnace our width was VERY limited. The homeowner has to squeeze between the furnace and dryer to do laundry and at the time of furnace install carrier didn't have a design with flue pipes thru the top, now they do! I think an "M" coil would be much better? Again tho, width is a factor. We did find today that they are siding the house. It's an older ranch style and there is virtually NO insulation in the walls! I think we may have found our problem? I still don't think this system is performing the way it was designed to...
My 2.5 ton maintains 70* at 100*, 1250 sqft, no insulation, with a basement, masonry walls all the way up. Plenty of windows. 2 floors.

By the way, your moving 525 cfm per ton, according to your 1050. A tad high. It is possible to have to much air across the coil.
Which makes sense for your delta T.

I doubt low speed for a 60k is 2.5 tons of air though.