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What are Solar Thermal Heating Systems

solar thermal heating

We provide kits, parts and components for solar heating systems

What are solar thermal systems?

Solar thermal systems by Regulus operate on the principle of transforming solar energy into
heat that is transferred into a heat carrier and can be further utilized. Unlike other renewable or
non-renewable sources, this one can supply energy almost for free, without any further significant
operating costs. While photovoltaic (PV) systems transform solar radiation directly into electricity
with max. 15% efficiency, solar thermal systems are able to utilize as much as 80% solar energy
and the average annual efficiency incl. winter is usually some 50-60%.


Energy efficiency and payback period for solar thermal systems

Taking into account the quantity of solar energy reaching the Czech Republic during one year
(about 1000 kWh per square meter), installation of a solar system will help you save a large part
of expenditures on domestic water heating, space heating, pool heating and other heat-consuming
technologies, maintaining your running costs very low.
Regulus Solar Systems excel at providing extra long service life exceeding 25 years thanks to the high-quality materials and components used, and their lifetime is several times longer than
their payback period.


What are solar thermal systems used for?

Solar thermal systems are mostly used for DHW (domestic hot water) heating. Such a
solution brings many advantages since DHW is needed all year round, i.e. also at times of peak
solar radiation, in contrast to space heating.
Another typical solar thermal system layout is a combination system for DHW and heating.
The solar thermal system is then usually connected to a combination Thermal Store used to feed
both DHW and space heating.
A solar thermal system is by far not so efficient like e.g. a heat pump when space heating is
concerned, however in well-insulated houses (esp. low-energy and passive houses) a
solar thermal system can bring savings not only on DHW but also in tens of percent on heating
costs. A pre-condition for using a solar thermal system for heating is a low-temperature heating
system, like underfloor heating or radiators designed for operating temperatures below 55°C.
Of course, solar thermal systems can be well used also for pool heating, not only for seasonal
outdoor ones, but also for year round indoor pools. These, however, will need a traditional backup
source – solar radiation is free but unfortunately not always available.
More applications and detailed info on solar thermal systems use are available in the section
dealing with detached houses or in the section dealing with blocks of flats.


What do solar thermal systems consist of?

A principle component of a solar thermal system is a solar collector, capable of absorbing solar
radiation and transforming it to heat. The heat trapped inside the collector is then transferred by
special antifreeze solar fluid into a solar thermal appliance.
A solar thermal appliance is usually a storage water heater where DHW is heated with solar
energy, or a Thermal Store with heating water heated from the same source, or e.g. a pool.
A solar thermal system needs to be backed up by a traditional source of heat, mostly an electric
heating element usually installed directly into a solar cylinder or Thermal Store.
In order to transfer heat from collectors into a solar cylinder, any solar system shall be equipped with a circulation pump. A circulation pump is included in a solar pump station that involves
also other important components of a solar circuit – a safety valve, flowmeter, non-return valve,
filling valves etc.
A solar expansion vessel is also connected to a solar pump station.
Since a solar cylinder may be heated up to as much as 90°C by a solar system, a hot water outlet
shall be fitted with a thermostatic mixing valve that keeps outgoing water at a safe temperature.


Solar thermal system design

solar thermal heating
Proper operation of the entire system depends on the right design of number and type of solar
collectors and the type and size of a solar cylinder. These components should be designed by an
expert with respect to the properties of the building in question. Contact us for more information