Since the late 1940s water source heat pumps (WSHPs) have been in use. They transferred warmth from a source of water to a property. Commercial developments often consider water source heat pumps as a renewable option when there is a nearby water source. They can deliver impressive results if, for example, it is in a small stream or river with water temperatures between 5-8°C. What is a water source heat pump (WSHP)? Water source heat pumps utilise the constant temperature of water as an exchange medium and this means that WSHPs can achieve a high efficiency of between 300-600% on cold winter nights. Benefits of a water source heat pump is that they are sustainable and efficient heating solutions, that generating less CO2 emissions than more traditional systems. Although electricity is required to power a water source heat pump in order to circulate water through the loop, you can expect to receive between two and four units of heat in return for every unit of electricity used. As with other heat pumps, a survey will check if your existing heating system compatible with a water source heat pump, a well-insulated property will benefit most from a WSHP system as the system is designed to maintain a consistent temperature within the property. It may be necessary to install underfloor heating and bigger radiators in order to get the most benefit from a water source heat pump. There are three types of system to choose from. Closed loop A closed loop system would be the lowest cost option for properties with access to a sufficient source of water. Starting at the building, a supply line is inserted through the ground to the water, intertwining into circles of a minimum of eight feet beneath the surface in order to prevent freezing. Coils need to be located in a water source meeting the minimum conditions necessary for quality, depth and volume. Hybrid A hybrid system uses geothermal resources, sometimes mixed with outdoor air, and is ideal for locations where the cooling requirements exceed the heating needs. Open loop An open loop system utilises a well or a surface body water as the heat exchange fluid travels through the heat pump. After it has dispersed though the whole system, the water returns to the ground via the well, a recharge well or a surface discharge. However, this type of system is only practical if you have access to a reasonable supply of clean water. All regulations and codes in relation to groundwater discharge must also be completed There are several other factors to take into consideration: Do you have access to a sufficient water supply? The more heat that your property needs, the bigger the water source required. Water source heat pumps really need a lake or river adjacent to your property and permission to use this for your heat pump source. If the water source is not sufficient, then the WSHP will reduce the temperature of the water and the system will not run efficiently. In extreme circumstances, this could even cause the water to freeze.