This question has got me quite confused, some guidance would be really appreciated. A room is to be kept at 23C using a heat pump from ambient. Heat gain to the room is 1.5kW per degree Celsius difference between the atmosphere and the room. 1) If the outside temperature is 32C, what is the reversible COP of the heat pump? I assume this is referring the maximum COP.. 2) What is the minimum work to drive the heat pump? I have used COP = Ql/Win to calculate this work input. 3) What is the maximum ambient summer temperature to be able to use the heat pump to cool the room to 23C? I'm really confused about this part. Thanks! Edit: I think I should have put this thread in the homework help section.