Water Sourced Heat Pump

Water source heat pumps use water as the heat resource. The can be classified due to the type of the water resource and piping mechanism.

The working principle of heat pumps, which use lakes or rivers as heat resource, is similar to ground source heat pumps. Capillary pipes have to be placed horizontally at least 2,5 m below the water as seen in the figure. The water and antifreeze mixture is circulated inside the calipary pipes and the mixture transfers the energy, extracted from water, to the refrigerant circulating in the heat pump. Then the refrigerant transfers this energy to the water circulating inside heating pipes in the house.

Seawater is a great solution for bigger heating capacities. The temperature of seawater is about 5-8^o C in 25-50m depth of sea. Those temperature values result in higher COPs which means lower electricity consumption. When seawater is used as heat source for heat pumps, what we have to be careful about is designing  the callipary pipes and pumping system corrosion-resistant and keeping the organic pollution at minimum level throughout the system.

The most proper water source for heat pumps is underground water since underwater resources are at higher temperatures even in winter season. When underground water is used as heat resource there is a need for 2 instinct well. One of the wells meet the hot water need continuously, the return water, which’s completed the cycle in the heat pump, is discharged into the other well. Since the water from the well is directly circulated inside the heat pump, the water has to be tested before using. The systems which uses underground water directly in the heat pump cycle are called as open loop systems.

The first initial cost of water and ground source heat pumps is more than that of air source heat pumps. Since the temperature of water and soil is less changeable when compared to air, the use of water source and ground source heat pumps are more efficient. The water and ground source heat pumps are preferred where the heating need is relatively higher and where the temperature difference between inside and outside is greater. However, you have to have enough land or water source around the ambience so as to use geothermal heat pumps.