An ideal reversible heat pump is taking heat from the outside air at -10.0°C and discharging it into the house at 18.0°C. What is the coefficient of performance of this heat pump?
A) 0.533
B) 10.4
C) 0.644
D) 0.0962
E) 9.44

Question

Quizplus · Accepted Answer

The coefficient of performance (COP) of a heat pump is given by COP = Qc / W, where Qc is the heat delivered to the warm space and W is the work input. For an ideal reversible heat pump, the COP can also be calculated using the temperatures of the heat source and sink: COP = Tc / (Th - Tc), where Tc is the absolute temperature of the heat source (in Kelvin) and Th is the absolute temperature of the heat sink (in Kelvin). Converting the given temperatures to Kelvin: -10.0°C = 263.15 K and 18.0°C = 291.15 K. Thus, COP = 291.15 / (291.15 - 263.15) = 291.15 / 28 = 10.4.

An Ideal Reversible Heat Pump Is Taking Heat from the Outside