Heat Pump SEER

[jimblu]

On a ductless inverter mini split, the SEER rating on the heat pumps is often 10% higher on the heat pump models than cooling only, for example 18000 BTU at 21 SEER for heat pump versus 19 for cooling only. The difference in acquisition cost would be made up in a year with our 3X US electric rates if it really is higher on cooling.

Is the higher SEER rating averaged in with heating, which we don't use in the Tropics, or are the heat pump models more efficient? Our contractor says he installs a lot of heat pumps because the ratings are higher, but he doesn't know for sure or have any supporting data. He just says his customers who ask for efficiency want the highest there is and that is what the brochure shows....

Thanks! Sorry to keep pestering with this issue but our electric rate is one of the highest in the world.

[beenthere]

SEER is a cooling only rating. So nothing about heating is taken into accout about the heating ability.

[skippedover]

If you don't use heating, then you should limit your system to a cooling only model. The heat pump function is simply not needed. On the other hand, if you want the bells and whistles that may not be included with a cooling only model, then the purchase of a HP may be your only option. The important numbers for a HP in heating mode are the EER and HSPF, principally the latter. But if you're not using it for heating, then SEER is the important number, the higher the number, the better the efficiency.

[beenthere]

HSPF is a very misleading number.

The Trane 16i has a very good HSPF, better then the 15i. However, the 15i is the better choice, since it has a higher COP, and better BTU output at lower temps.