Swimming pool tips
Geothermal & Ground Source Heat Pumps
5. RETROSPECTIVE INSTALLATION :
It is not easy to retrospectively install a ground source heat pump onto an existing project which was designed around a conventional fuel boiler. The original environmental control unit and the air distribution ducting would not be adequately sized to compensate for the much reduced heating circuit temperatures. Such a system would struggle to maintain conditions through the winter months.
OUTDOOR POOLS :
For a typical summer use outdoor pool, a ground source heat pump is not a viable approach.
This is simply because, during the summer months, the ambient fresh air temperature is warmer than the ground temperature. Therefore, a conventional air source swimming pool heat pump would offer superior efficiency during this period.
An outdoor pool which is used during the winter may gain some benefit from a ground source heat pump, but the heat pump is unlikely to offer much contribution towards the very high heat losses from the pool during such periods.
Obviously, with a dwelling within the UK, generally all the domestic air heating requirements for the winter season will, in contract, occur when the ambient fresh air temperature is less than the temperature underground.
SPA WATER HEATING :
The low temperature of the water circulated through the central heating circuit with a GSHP is an issue for heating spa water.
If the spa is to be heated up to a maximum temperature of, say, 40°C, there is only minimum temperature difference available to achieve meaningful heat exchange.
It is not theoretically impossible to heat the spa, given a huge heat exchanger, but a more practical approach would be to omit the spa heat exchanger and use a direct electric heater instead.
HOUSE AIR CONDITIONING :
Some more complex ground sourced heat pump installation have the ability to operate on a reverse cycle principle during the summer months, whereby they provide cooling in the house and transfer the excess heat into the ground via the ground pipe loop. During the winter months, when heating is required, some of this energy can be re- absorbed and utilised. It is unlikely such a facility can be utilised practically within a swimming pool application.
SUMMARY :
The use of ground source heat pumps, instead of fuel boilers, will invariably continue to expand and, in the long term, may become a standard approach.
Heatstar have embraced the concept of operating their swimming pool systems in conjunction with ground source heat pumps and have developed a special range of products designed specifically to overcome the characteristics involved.
Heatstar have also already developed the necessary software to predict the genuine operating cost benefit involved in using a ground heat pump on any given indoor pool application and to confirm the necessary flow rates involved etc to the installers.