As part of an extensive refurbishment of a large detached old vicarage we installed two 20-tube solar thermal collectors to supply hot water. These collectors have been mounted on the south west facing inverted pitch between dual pitch roofs, and they are not visible from the ground. The roof can be accessed via a roof light for inspection and maintenance.


The capacity of the Navitron SFB2058 collectors has been designed to match the household’s hot water requirement between late spring and early autumn, and to make a substantial contribution at other times, offsetting the heat that would otherwise need to be supplied by the gas-fired boiler.


Approximately 15m of pre-insulated Solarflex pipe connects the collectors on the roof to a 300 litre unvented hot water storage cylinder in the basement. This is a triple coil cylinder with two solar coils and a boiler coil. Initially heat from the solar collectors circulates through the upper coil to heat the upper part of the tank. Once this has reached its set-point further heat is diverted by a 3-port valve to the lower coil. Compliance with G3 building regulations is achieved by venting to a sump dug into the basement.


The solar circuit is controlled by a solar pump station and a Resol differential temperature controller.