What is the difference between flat plate and evacuated tube?
The main component of a solar water heating system is the collector (often referred to as a solar panel) and its function is to collect the heat from the sun and transfer it to a fluid in the collector which in turn transfers it to the water in a hot water cylinder. In the UK the type of collectors fall into two main categories – flat plate or evacuated tubes and, although there are variations available for each type of collector, the way they work is very similar. However, flat plate collectors can be either fixed onto the existing roof covering (slates/tiles etc) or integrated into the roof itself, whereas evacuated tubes must always be fixed onto the existing roof. Evacuated tubes are often considered to be slightly more efficient than flat plate collectors because the vacuum within the tube provides additional protection against heat loss, although they are generally more expensive than flat plates, but this can be easily compensated for by installing a slightly larger array of fla
