Frost Damage in Heat Pipes

German manufactured products are famous for being rigorously tested. One of the leading test institutes is TUV Rheinland which has a special expertise in testing thermal solar evacuated tubes. Evacuated tube solar collectors were originally designed by Dornier in Germany. There are various kinds of evacuated tubes but one popular and expensive kind is the tube which contains a heat pipe – a sealed pipe which usually contains a fluid which expands and contracts according to the heat and delivers heat through a manifold through which a freeze resistant glycol is passed as a heat exchange medium. Continue reading

Which is better – solar flat panels or evacuated tubes?

I am often asked about the difference between evacuated tubes and flat plate solar panels; people want to know which is better and there are some confusing websites out there, particularly those which extol the virtues of evacuated tubes, so I shall let you have my views on each type of product. You will have to bear in mind my own bias; after some considerable research I invested my own money in a flat plate factory for Genersys; I personally decided my preference and the reasons have not changed in the past eight years. Continue reading

What you need to know before you buy a solar system

Do you make sure that you buy the best solar system for you? There is a lot of misleading information about solar systems that produce hot water, and some of it is put out by UK organisations that should know better and are reluctant to share how they arrive at their information. I hasten to add that none of these organisations has any particular expertise in solar thermal technology, but they publish low payback figures as though they were authoritative. Continue reading