Ground source heat could be the new answer to renewable energy use. The new Gledhill unvented stainless steel unit, the 'Stainless Lite', specifically for heat pump applications is designed specifically with renewable energies in mind. Utilising the well established Gledhill Stainless Lite unvented hot water cylinder, this product has been developed to maximise the lower temperatures typically available from heat pumps.

The heat exchanger is a totally new design. It consists of a two pass corrugated stainless steel tube in parallel to reduce the pressure loss whilst maximising the heat exchange. Many medium to large heat pumps need heat exchangers in the store that will cope with the higher flow rates associated with primary temperatures that are typically 50˚C or 60˚C.

All the usual features of the Gledhill Stainless Lite are maintained together with controls* and expansion devices included. (*with the exception of solar control and Heat pump contol that should be supplied with these add-on systems)
 

Due to the fact that many heat pumps will not raise the stored water temperature to 60˚C, which is necessary to prevent the growth of legionella, the Stainless Lite HP model is supplied with an immersion heater tapping and a thermostat pocket.
 

It is recommended that a thermostat is fitted which brings the immersion heater ‘on’ at a temperature just below the heat pump maximum (if required) and switches off at 60˚C or 65˚C. In this way the use of ‘direct’ electrical heating is minimised and most of the hot water is achieved from the heat pump and solar input as available.