It is possible to use solar heating to augment the space heating in a house. In a well insulated house, the percentage of space heating provided by the solar heating system will normally be in the range of 10-20%.
Accurate sizing of solar collectors and thermal stores for solar space heating systems can only be done using computer simulation programs.
The most popular solar design programs including T*Sol and Polysun provide this facility.
Typical Solar Central Heating Systems for Houses
In order to use solar energy to contribute to the space heating of the house, a large thermal store (buffer) will be needed in the system. This can be heated by solar energy and other heat sources such as a boiler or heat pump. As a rule of thumb 80 litres of buffer capacity will be needed per m2 of collector aperture area.
Typical configurations are shown below.
System with Conventional Buffer tank
The diagram shows a buffer tank which acts as a thermal store for the solar system. This is an insulated mild steel tank fitted with a heat exchange coil.
The water volume contained in the buffer stores energy from the solar heating system.
Solar Central Heating System using Buffer tank
The upper part of the buffer can also be heated by a boiler or heat pump. This configuration is useful in many heat pump or wood fired heating systems.
System based on TiSun PRO-HEAT tank
This option uses the TiSun Proheat tank fitted with an external spherical heat exchanger. The principle of operation is similar to the previous system.
The PRO-HEAT solution has the advantage that the special spherical heat exchanger attached to the PRO-HEAT loads the solar energy into the buffer tank from the top downwards. This ensures that there is good stratification of the water contained in the tank.
Hot water is available for use from the top of the tank early any day when the sun shines. The efficiency of the solar panels is also optimised as the bottom of the tank is as cool as possible. This allows the solar heating system to operate at the lowest possible temperature and therefore at the highest possible efficiency.
Solar Central Heating System using PROHEAT tank
Further information on the PRO-HEAT product range may be found by clicking here.
System based on TiSun PRO-CLEAN tank
The TiSun PRO-CLEAN tank can also use the spherical heat exchanger described above. However, this tank also heats the domestic hot water via a high surface area stainless steel coil. This coil contains the domestic hot water and a separate water heater is not needed.
The stratified charging system ensures that the warmest water is always available at the top of the tank in order to rapidly heat the domestic water.
The system also has the great advantage that the volume of stored hot water is minimised thus eliminating the risks associated with storing domestic hot water. In particular the risk of legionella infection is minimised.
Solar Central Heating System using PROCLEAN tank
Further information on the PRO-CLEAN product range may be found by clicking here.
Alternative system based on TiSun FS tank
The TiSun FS tank is similar to the PRO-CLEAN in that it contains the same high surface area stainless steel coil. This is used to heat the domestic hot water. However the FS tank does not have the option of fitting the stratified charging system ;it has a solar coil instead.
The FS tank system is suited to budget applications where stratification is not a priority.
Solar Central Heating System using TiSun FS tank
Further information on the FS product range may be found by clicking here.