What is an open loop non-tidal collector?
Open loop non-tidal water collectors are used in ground source heat pump installations to abstract and filter the water through the heat pump.
Open loop non-tidal water collectors take the form of two separate straight pipe collectors. As per all open loop system collectors, no anti-freeze fluid is featured in open loop non-tidal collector installations. These installations involve the water from the water source being abstracted and filtered through the ground source heat pump. This water is then discharged either back to the water source or another acceptable discharge area.
Consideration needs to be taken with regards to corrosion issues, filtration, extraction and possible freezing within the heat exchanger. It is also important to consider the electrical energy required to pump the water to the ground source heat pump.
Water collectors have a number of advantages:
- The heat transfer rate from water is higher than that in the ground;
- The water is in close contact with all of the pipe at all times enhancing it’s efficiency;
- The flow/circulation of water provides constant energy replacement;
- The use of a water source removes the need for digging or drilling, reducing the cost and duration of the installation;
- The return temperature to the heat pump is generally 5-6°C higher than ground collectors, increasing the efficiency of the heat pump.
Things to consider
If you are considering an open loop borehole for your ground source heat pump system, there are a number of points which need to be taken into consideration:
- Seek relevant permissions from the Environmental Agency
- Consider the design of any scheme to ensure its longevity and efficient performance