Open Cycle COPs The single most important measure of industrial heat pump performance is the Coefficient of Performance, or COP. COP is a dimensionless number defined as the ratio of the energy output and the energy input (all expressed in heat equivalents).
For example, a 50 kW heat pump delivering 1 million Btu/hr has a COP of 5.86.
where Tcond is the temperature at which the refrigerant used in the heat pump condenses and Tevap is the temperature at which this same refrigerant evaporates.
COP ~ 0. 6 * (468 + 120)/(120 - 85 + 16) = 6.92.
1,000,000 Btu / (3413 Btu/kWh * 6.92 COP) or 42.34 kWh.
This means that every million Btu of heating at 6.92 COP requires 42.34 kWh.
If we assume an industrial electric rate of $0.06 per kWh, the cost of the heat recovered by the heat pump is $2.54 per million Btu - much less than most industrial firms' cost of steam.
If the heat pump does not influence peak electrical demand (which may be possible by interrupting the heat pump during peak periods), the average price per kWh may be very low. This could improve the heat pump economics.