ASHP Selection

GarthK

Hi all. 
In my area the ratio of hydro to natural gas prices on a heat provided basis is about 3.0. So a heat pump needs to be operating with a COP above 3 to save money vs gas, and so far the models I've looked at will only achieve this when the temperature is well above freezing. So if savings are my priority, then a cold climate HP makes no sense. So to me a high efficiency non CC model would be the way to go, coupled with an extra smart thermostat that will select the less expensive heat source based on "real time" energy prices.

If this thinking makes sense, any suggestions for models that would best fit the bill (ducted, hybrid with gas furnace)?

Also, so far I am only aware of one thermostat that will currently do this (BKR Energy). Is anyone aware of any others?

Thx

Garth

pecmsg

GarthK said:

Hi all. 
In my area the ratio of hydro to natural gas prices on a heat provided basis is about 3.0. So a heat pump needs to be operating with a COP above 3 to save money vs gas, and so 
Thx

Garth

How did you come up with that?

hot_rod

The COP has to do with the temperature you are trying to run also. Keep it below 120F helps keep the COP high.

It's all about the source and sink temperature relationship. 3 and above COP is tough if you get below 25- 30F and need 110- 120.

80- 90° radiant design SWT helps with COP numbers

Ignore this if you are talking about an air to air heat pump, although the same concept applies as far as the temperature differences. Air to air tend to blow lukewarm air as outdoor temperature drops. Or backup elements kick in$

Hot_water_fan

Most all furnace manufacturers have hybrid set ups: Mitsubishi, Trane, Lennox, etc! This is an easy one.