Refer to the gases & liquids, state y water was used in the early heat pump system ?

Question

rane · Answer

@Diwakar

anonymous · Answer

i really do not know much about these. Long time since i read thermal physics. But i think it may have to do with the high specific heat capacity of water.I think water's specific heat is highest of all compounds. Due to high specific heat ,we are able to extract/dissipate large amount of heat energy from/to the source/sink without getting the water to reach very high/low temperatures. 

This is my opinion and it is quite possible i may be wrong.

rane · Answer

so this could be y  water was used in early pump system

rane · Answer

?