Heat pumps are basically a reversed cycle of an air conditioner, refrigerant R32 is the working fluid in our heat pumps, initially the fluid is liquid, refrigerant absorbs energy from the ambient air through the evaporator causing it to evaporate which leaves the R32 in the gas state. After that the gas refrigerant escapes to the compressor in which it’s heat and pressure are raised to the highest in it’s cycle, then it flows to the condenser, which operates as a heat exchanger, the heat of the refrigerant is exchanged with the low temperatures of the water in the pool system, causing the refrigerant to turn into liquid and heating the pool water. Finally, the liquid refrigerant goes back to the initial point which is the evaporator to repeat the cycle again for pool heating.