A heat pump is used to keep a house warm at 22C. part a) How much work is requir

Question

A heat pump is used to keep a house warm at 22C.

part a) How much work is required of the pump to deliver 2600 J of heat into the house if the outdoor temperature is 0C. Assume a COP of 3.0 Express your answer to two significant figures and include the appropriate units.

part b) How much work is required of the pump to deliver 2600 J of heat into the house if the outdoor temperature is -15C? Assume a COP of 3.0 Express your answer to two significant figures and include the appropriate units.

part c) How much work is required of the pump to deliver 2600 J of heat into the house if the outdoor temperature is 0C. Assume an ideal (Carnot) coefficient of performance COP = TH/(THTL). Express your answer to two significant figures and include the appropriate units.

part d) How much work is required of the pump to deliver 2600 J of heat into the house if the outdoor temperature is -15C. Assume an ideal (Carnot) coefficient of performance COP = TH/(THTL). Express your answer to two significant figures and include the appropriate units.

Explanation / Answer

a) COP heating = amount of heat extracted from a cold reservoir / work

3 = 2600 J / W

W = 866.67 J

b) COP heating = amount of heat extracted from a cold reservoir / work

3 = 2600 J / W

W = 866.67 J

c) COP = T_hot / (T_hot - T_cool)

COP = (273 +22) / [(273+22) - (273 +0)] = 13.41

13.41 = 2600 / W

W = 193.89 J

d) COP = (273 +22) / [(273+22) - (273 -15)] = 7.97

7.97 = 2600 /W

W = 326.10 J

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects