Could anyone help me determine the manufacturer and capacity of this forced-air unit. Thank you.
Model number:
PGAD36D1K4
Cant tell the manufacturer fromt that. But it looks like a 3 ton unit.
Lawrence,
If this will help at all, it is likely one of the following manufacturers: Especially if it is a four tube heat exchanger.
Comfortmaker, Heil, ICP, Tempstar, Whirlpool.
Erol Kartal
Pro Inspect
Yep…
ICP, Heil Replacement Heat Exchanger (4 Tube): American HVAC Parts … PGAD36D1K1 PGAD36D1K2 PGAD36D1K3 PGAD36D1K4 PGAD36D1K5 PGMD24G075 PGMD24G0752 PGMD24G0904 PGMD24G0905 PGMD24G0906 PGMD30G075 PGMD30G0752 PGMD30G0904 …
americanhvacparts.com/.../merchant.mvc?Screen=PROD&Product_Code=HEAT1084480A&Category_Code=Heihe - 57k - Supplemental Result - Cached - Similar pages
Internet research skills…
If it’s on the web, Dale, David V. and I can find it. 
Erol Kartal
Pro Inspect
Wow…
I always type the serial number or model number into Google…just like Dale did…amazing what you can find with what appears to be random numbers and letters jammed together…
Which Google class did you take to learn that ?
Took a college level internet course several years ago.
It is amazing what you can find on the World Wide Web with proper keyword selection.
Erol Kartal
Pro Inspect