SAVE BIG ON HEATING COSTS WITH AIR EXCHANGE HEAT PUMP / AC
What is an air source heat pump?
An air source heat pump is basically a dual mode air conditioner that can operate in reverse. It can move heat
into the house in the winter just like it moves it out in the summer. When the super cold refrigerant is exposed to
ambient air it “boils” and changes to a warm gas. This is just like removing heat from your refrigerator and
blowing it out the bottom into the kitchen.
The efficiency of an air source heat pump is very high during milder winter days. When the temperature outside
is 40 F many models operate at 400% efficiency (and higher as it gets warmer). This means that every watt
(3.412 Btu) of electricity you pay for creates 4 watts (13.65 Btu) of heat energy!
Efficiencies in standard models (8-9 HSPF) do drop down to about 200% at freezing, and these models produce
less heat at temperatures below 25F. This means that your current heating system should be kept to warm your
house on the colder days of the winter. A new heat pump model with HSPF’s of 10 + can be cost effective for
heating down into the teens or even single digits.
How much can I save on energy with one?
There are no heating systems that can beat cost of operation of an air exchange heat pump at temps 40F and
above. When temperatures are in this range, by switching to the heat pump, our customers are reducing their
heating fuel consumption significantly. Central heating systems are least efficient at these temperatures. At our
latitude (NH) central heating is normally required from mid Sept through early May. In most cases a standard
heat pump can reduce this range by 4 - 6 wks on each shoulder. A Hyper heat model can perform even better.
If you heat with wood, you know it can get way to warm when it’s in the 40s to low 60s outside. A heat pump cost
pennies to run at this temp and it’s far more economical than opening the windows to control the temperature.
The minimal cost to run the highly efficient AC mode in the summer is more than paid for from the savings on
heating in the spring and fall.
Current method of heating
If you are currently using electricity, propane or oil then you have greater potential for savings. Also, if you are
currently using an older, less efficient system you will have greater savings too. An explanation of how to
compare the HSPF efficiency rating of heat pumps to the efficiency ratings of oil and gas systems can be found
at http://604goodguy.com/heat-pumps.html
Climate region
A standard air source heat pump is very efficient on milder winter days but the efficiency does drop as outside
temps drop. In general, heat pumps are attractive in the Pacific Northwest because of the mild winter weather.
They are also attractive to many Northeastern homeowners who are currently using expensive oil or propane to
heat their homes. Despite their low heating costs, many Southern homeowners would be wise to invest in a Heat
Pump / AC when their air conditioner needs to be replaced. They only cost about 20% more than a cooling only
AC unit.
SAVE BIG ON HEATING COSTS WITH AIR EXCHANGE HEAT PUMP / AC
Efficiency Rating Definitions

SEER (Seasonal Energy Efficiency Ratio “for Cooling”)
Total Cooling Output Over the Cooling Season] / [Total Electrical Energy Input Over the Cooling
Season 19 SEER model
36,000 BTU/hr x 720 hours / 19.0 SEER = 1,364,210 watts / 1,000 to convert to KW = 1,364 KW x
$0.10 = $136 for roughly 30 days of continual maximum output 24 / 7 operation. (In reality the output
would go down as temps cool in the evening until rising again the next day.)

HSPF (Heating Seasonal Performance Factor)
The total heating output of a heat pump during its normal annual usage period for heating divided by
the total electric power input in watt-hours during the same period.
12,000 Btu Heat Pump heating for 30 days @ Approx 40F 12000 x 24 hr x 30 days = 8,640.000Btu /
720.000 W (based on 1000 watts consumption per hr ) HSPF = 12
The HSPF can be regarded as an "average" COP for an entire heating season. It is common to compare BTUs
of heat output to watts of electrical energy input. HSPF of 6.8 can be compared with an average COP of 2 and a
HSPF in the range of 5-7 is acceptable.

COP (Coefficient of Performance)
A ratio calculated by dividing the total heating capacity provided by the system (Btu's per hour), by the
total electric input (watts) X 3.412 (Btu/W).
For example, a Heat Pump with a COP of 2 puts out twice as much energy (in the form of heat), as it
uses.
Example – COP Cooling Cycle - Delivering 60000 Btu/h with a total input of 9 kW:
COP = 60000 (Btu/h) / 3.412 * 9 (kW) = 1.95
Heating Cycle - A heat pump delivering 50000 Btu/h with a total input of 7 KW:
COP = 50000 (Btu/h) / 3.412 * 7 (kW) = 2.1
In 2004 SEER & HSPF rates on Mitsubishi AC / Heat Pumps were 10.2 & 6.8
Starting in 2008, Hyper Heat / AC models have up to 26 SEER and 10.6 HSPF
Most standard models have SEER’s at 19 or higher, Most HSPF’s are at 10 or higher