The Cross Potato is equipped with a mains cold water fed Chaffateaux hot water heater. The rear of the shop faces due south and provides an ideal opportunity for solar water heating.
The installation consists of a 20x 58mm heat pipe evacuated tube solar collector Supplying a 122 litre factory insulated stainless steel single coil mains pressure hot water cylinder. The heating coil is connected to a glycol antifreeze circuit with solar pump to collect the free solar heat from the evacuated tube panel.
The system is controlled by a Resol ES-4 controller complete with pump speed controller and digital temperature display. Thus the mains water is preheated in the hot water cylinder before passing to the water heater to be further heated if required, or used directly if not.
4 BEDROOM DETACHED HOUSE
South west, South east aspect with partial shading, from roof profile and mature trees in front of house.
The installation consisted of two SOLARGREENPOWER 58mm heat pipe evacuated tube collectors, a 30 tube on the SW aspect, and a 20 tube on the SE aspect. They Supply a Stainless steel 300 litre factory insulated twin coil mains pressure hot water solar cylinder. The upper coil in the cylinder is connected to the central heating condensing boiler, to permit hot water temperature boost when required, and the lower coil is connected to a glycol antifreeze circuit with solar pump and bypass valve to collect the free solar heat from the evacuated tube panels.
The whole system is controlled by a Resol deltasol M solar controller which provides total control of the system incorporating, two calorimeters, one measuring solar heat collected and actually transferred to the hot water in the cylinder via the lower coil, and the other measuring the actual quantity of heat in the domestic hot water used.
Therefore the above control allows direct measurement of the amount of heat energy saved by the solar panel on a daily, weekly, annual basis in kW hrs.
In addition the controller measures the solar irradiation, and provides weather compensation control of the central heating boiler.
The directly measured solar heat obtained in the above system is not subject to the usual inefficiencies of heat production i.e. Boiler efficiency, or electric resistance heater efficiency. As such its fiscal value is greater by a significant factor depending on which form of energy is used to heat the water.
Factor of 1.205 (Nat gas Condensing Boiler Efficiency @ 60ºC = 83%)
Factor of 1.053 (Electric resistance heating @ 60ºC= 95%)
South west, South east aspect with partial shading, from roof profile and mature trees in front of house.