Evaporator sizing - is bigger better?

[AC_Hacker]

Originally Posted by jeff5may

This is in reference to the indoor coil in an air handler. With a heat pump, oversizing the indoor coil too much will kill your supply air temperature. Instead of 120 degF air coming out of registers, you will have 110 degF air, which feels "not so hot". Efficiency may rise a smidgen, but the overall "warmth" provided may be seen as diminished by the average user. Not a good thing to most.

This is very curious...

If your logic is correct, you have just defeated heat pump heating, and all other low temperature heating strategies.

Because heat from an oil fired heating duct can be uncomfortably warm, but does that mean that a heat pump heated house with the same inside air temperature would feel less warm, therefore less satisfying than oil heat?

If you wanted to actually enjoy the efficiency gain of a larger condenser, you would need to increase the volume of air through it, to get those BTUs into the room.

Or, if radiant floor was your heating method, you would need to increase floor efficiency through lower R-value materials above the heated part of the floor structure, and/or increased pipe density and/or increased water flow rates.

-AC

-AC