That formula is only for the sensible heat and not the latent heat. Q=m delta hHi,

I have a SSZ140301A with CAPF3636*6A coil with TXV. There is only the TXV at the indoor coil for AC Mode, no TXV in the outdoor unit for the Heat pump Heat Mode.

My variable speed blower is set to 1125 CFM

I measured:

Outdoor Temperature: 75

Indoor Temperature at return: 71.3 (After 20+ minutes of running)

Indoor Temperature at supply: 51.3 (After 20+ minutes of running)

Indoor wet bulb Temp: 65.5

From the Datasheet using a larger coil the expanded cooling data suggests:

At 1181 CFM, Indoor Dry Bulb = 70, Indoor wetbulb = 67, Outdoor Temp = 75

MBh = 31.3

Hi PR =281

Lo PR =137

Amps = 3.2

Delta T = 12

S/T = 0.45

Some Questions:

1. What will my smaller coil (3636 vs 3642) do to the data?

2. My BTU/hr is only 24,300 using the 1125*1.08*20F formula, the table suggests I should be getting 31,300, is this a sign of something?

3. The Delta T, is that the out door or indoor temp rise?

4. What is S/T?

5. What will be the signs if the system is under or over charged?

Delta T is indoor