Solar thermal systems can support hot water preparation in every household. In contrast to heating, the demand of hot water is nearly
stable over the year. The principle of hot water preparation through the sun is easy and known for a long time. In the early days of
the sun use, solar energy was captured by use of simple methods. Full vacuum tube collectors are much more effective and generate even
in winter high yields.
What should be noted when planning a solar process heat system?
When planning a system for domestic water heating, the hot water demand must be estimated. If there is no ability in the household
to read the hot water demand from a measuring instrument, it can be assumed a demand of 30 l – 50 l per person and day. The demand
of washing machines and dish washers also should be taken into account, because they can be operated with hot water from the solar
system to reduce the electricity consumption as well. When employing the 100° C tube, it can be assumed always 30 tubes. Thus the
solar coverage is higher and there is no risk of overheating.
Alongside the hot water demand, it is furthermore essential to consider the storage type and size, because it plays an important
role for the efficiency of the system. The average size of solar hot water storage tanks amounts 300 l – 600 l. Most suitable
is a buffer storage with fresh water station. Hygienic storage tanks are also reasonable, because they heat the water in the
hygienic continuous flow mode. Drinking water tanks are not to recommend to prevent the growth of Legionella. Buffer storages
are the cleanest and most effective solution for a combination of domestic water heating and heating
What is saved?
With a high efficient full vacuum tube collector system, it is possible to prepare hot water in the transitional period as well
as in winter. So a major part of the heating costs for the hot water preparation can be saved.