Solar Heating

Solar energy can be exploited for heating systems using flat panel collectors or evacuated tube collectors.

Such systems typically use heat obtained from the sun to warm hot water for household use, though the heated water can also be used to heat space. The most common technical solution is to heat a water/glycol mixture for a pump-driven fluid circulation system. The heated fluid flows from the collectors through pipes that take it to an insulated heat storage reservoir. Evacuated tube collectors are more efficient than flat panels, since they can collect scattered radiation more effectively.

Solar energy usable together with many other energy forms

Homes with under-floor heating systems can gain more energy from solar heating systems, because the temperature of the circulating water is lower than in central heating systems using radiators.

Solar heating systems are generally designed to meet a property’s heating needs during the summer months, which largely concern the need for household hot water. The storage reservoir should have a sufficient capacity to last for a few days. During the winter, when the daylight hours in Finland are very limited, solar heating systems can only be operated in conjunction with other parallel primary heating systems.

Roughly half of the hot water needs of a detached house can be obtained from a total solar collector surface area of 5-8 m². To heat the rooms as well, solar collectors with a total area of 10-12 m² would be needed.