I have recently moved into a 23 year old house with the original 3 ton heatpump. I am going to be getting quotes for a new system and get it replaced before it fails. Thinking of either a Lennox XP19 or a Carrier Infinity. I suspect my current system is oversized due to the fact that duct system is much loader than heatpump in my older home and it heats much better and very rarely does aux. heat come on.
Here are results of load calc that I have done:
3 bedroom Cape Cod on Slab with a lot of glass
2100 sq. ft.
Outside Design Conditions: 88/14 105 grains of moisture
Inside Design Conditions 72/72 50% Humidity
Total Heat Gain 25,904 BTUH
Sensible 21,895 BTUH
Latent 4,009 BTUH
Heat Loss 39,748 BTUH
1. I know there is a correction because of using 72 deg. indoor temp but not sure what it is.
2. Even with correction seems like 3 ton would be way oversized. Would probably run on first stage all the time. Does anyone make a 2 1/2 2 stage heat pump?