Water Source Heat Pumps
Water Source Heat Pumps collects energy from a water source: A pond, lake, river, brook or a moat. The heat pump unit is the same as for ground source systems. The difference is that the external pipework is submerged in water rather than buried in the ground. The collector pipework can be arranged as “pond mats” which is a coil of pipes fixed to a metal frame, or a bespoke arrangement of pipework to match site specific requirements. A water source system can be more efficient than ground source, especially if there is moving water.
As with all types of heat pumps, it is important to specify the right size (kW) heat pump. For this a room by room heat loss assessment of the property is required. A heat pump produces less hot water than a boiler and the lower temperature it can operate at, the more efficient the system is. Therefore, the overall efficiency of the heating system requires heating distribution (underfloor heating, radiators or fan coil units) which can deliver comfortable room temperatures at low operating temperatures.
The equipment that goes into the property is exactly the same for ground source and water source. The difference is the collection of heat from outside. A water source system collects energy with pipe work in a lake, river, brook, moat or a pond.
If the system collects energy from a moving source of water- e.g. a river, a brook or a pond with an inlet and outlet of water- the efficiency will be higher. If the system collects energy from a pond or a moat without water flowing through, the efficiency depends on the volume of water the pipes are immersed in. If you put too much collector pipes in a small volume of water, it can deep freeze and the efficiency would be lower. This always comes down to design.