Solar thermal water heating systems are highly efficient and this system from Stokvis substantially reduces the amount of parasitic energy lost (energy used up by the system itself during the process of converting solar energy to heat).
As a result, it requires smaller pumps to circulate the fluid in the evacuated tube collector which means that there are fewer drops in pressure through the system, giving a sustained level of heat.
As a result solar thermal heating is the most realistic renewable energy solution for most commercial building applications.
However, solar systems require some form of storage which can mean Legionalla problems and one answer is a hybrid water heating system employing solar thermal technology combined with a low water content plate heat exchanger.
Plate heat exchangers are ideal for use in systems with rapidly changing heat outputs because they are low water content and can therefore respond to changing requirements quickly.
They come complete with primary pump(s), a fast-acting motorised control valve on the primary circuit and a purpose-built PID controller to sense secondary water temperature and control the motorised valve.