The performance of a heat pump degrades (i. e., its COP decreases) as the temperature of the heat source decreases. This makes using heat pumps at locations with severe weather conditions unattractive. Consider a house that is heated and maintained at 26°C by a heat pump during the winter. What is the maximum COP for the heat pump if heat is extracted the out door air at 10 C?

Question

Engineering

Pierce Pham

25 May, 16:49

The performance of a heat pump degrades (i. e., its COP decreases) as the temperature of the heat source decreases. This makes using heat pumps at locations with severe weather conditions unattractive. Consider a house that is heated and maintained at 26°C by a heat pump during the winter. What is the maximum COP for the heat pump if heat is extracted the out door air at 10 C?

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Answers (1)

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Josh Burns · Answer 1

COP_max = 18.69

Explanation:

We are given;

Heated space temperature; T_H = 26°C = 273K + 26 = 299K

Temperature at which heat is extracted; T_L = 10°C = 273 + 10 = 283K

Now the Coefficient of performance (COP) of a heat pump will be a maximum when the heat pump operates in a reversible manner. The COP of a reversible heat pump depends on the temperature limits in the cycle only and is determined by the formula;

COP_max = 1 / (1 - (T_L/T_H))

Thus,

COP_max = 1 / (1 - (283/299))

COP_max = 1 / (1 - 0.9465)

COP_max = 1/0.0535 = 18.69