Our 2016 Solar Water Heating Pump Controller is one of our most popular products. Pictured below is a derivative recently requested by one of our clients.
This controller will be used to control the operation of a pump circulating water through a solar thermal panel. Our standard controllers have at least two sensors – one for the pool/tank and one for the solar panel – but for this particular project only one sensor could be used: at the solar panel.
Therefore, instead of using the temperature differential between the solar panel and the pool to decide when the pump should be turned on or off, the user sets a high temperature threshold above which the pump will turn on, and a low temperature threshold below which it will subsequently turn off.
Sensible starter values would be 70 degrees C at the panel to turn on the pump, and around below 35-40 degrees at the panel to turn off the pump. With experimentation and analysis (this device has a built in datalogger) it will be possible to refine these thresholds to maximise efficiency. The pump should not be turning on and off too frequently and running for very short times, but the panel should also not be left at very high temperatures for a long time or it will radiate heat away before it can be transferred to the water.
If this device was to be used in a small pool or hot tub, and if the arriving hot water from the panel is pumped straight in without pre-mixing, a lower pump turn on temperature would be essential so that no-one gets burned on the incoming hot water.
If you need any kind of pump controller, email neil@reuk.co.uk with details of your specific requirements.