Frequent reader, firts-time poster - just registered.
I'm hoping that one of you professionals can help me determine if it's normal to pick up heat in the blower section/furnace in AC mode.
I have a 2-story home and the furnace/air handler/evap coil are located in the blazingly-hot attic space. It's a Bryant 376CAV installed horizontally with the return air on the right as you look at the control-panel side. The Carrier 3KCB coil is on the left.
I've been told that the AC for the second floor is a tad undersized, so I'm making sure that it is running as efficiently as possible. I have a 2.5 ton Bryant 561C on a 2200sf second-floor.
I recently moved into the home. It was built in 1999 and the AC is all-original.
The installer, or subsequent servicer, made test holes on each side of the evap coil. Using a digital thermocouple two-probe thermometer I borrowed from work, I see a 20-degree drop across the coil. 77 degree air after the blower, just in front of the coil, and 57-degree air after the coil. From what I've read here, that's probably good.
Using the same thermometer, the temp in the test hole in thereturn plenum right in front of the furnace reads 74. I took this reading several times and used both probes to make sure I had a good number. If I'm at 74 entering the 376CAV and 77 leaving it, where is that heat coming from?
Does the blower motor introduce that much heat? Dies it pull in some fresh air by design? Any input in greatly appreciated.
My father spent 21 years in your industry working in hot attics and hot supermarket roofs. I know it's hard work.
Thanks in advance for your assistance.