Differential thermostat for solar heater - has two operating cylinders and amplification linkage to move valves for connection of heater to space or water heaters

摘要

The differential thermostat (11) is operated by pistons of two cylinders (12,13). The pistons are actuated by fluid expansion probes (20-22). One probe (20) senses the return water temperature to the solar panel whilst another probe (21) senses the hot water flow temperature from the panel. The last probe (22) is installed in the domestic hot water storage tank. The first and last probes both activate one piston (13) and the other probe (21) activates the second piston. The movement of the pistons is transmitted to valves (Va) through an amplifying linkage (16,17) which provides a rapid change-over operation. This directs the hot water, from the solar collector to the space heating or the domestic hot water.