In our conditions, solar collectors are most often used to prepare hot water. A smaller part of the installations also serves to support heating and / or hot water in swimming pools. Applications for the production of industrial heat up to 100 ° C are also common in the world.
To prepare domestic hot water for 4-5 pepople is it is necessary to install approx. 5 m2 of collector area. In the case of support for swimming pool heating or heating, a larger area is needed, which must be determined by calculation
based on the energy balance. This calculation can be performed for you by one of our contractual partners.
The achieved temperature depends on the intensity of solar radiation, the type of collectors used and the purpose of their use. In principle, it is also possible to reach temperatures above 100 ° C, but these are usually neither necessary nor meaningful. The hot water is usually heated to 55-65 ° C. Importantly, the higher the required temperature, the lower the efficiency and energy yield of the collectors. At temperatures above 60 ° C, the risk of limescale formation increases.
From collectors manufactured and sold by thermosolar Žiar s.r.o. we recommend choosing according to the following principles:
● for domestic hot water preparation, heating or heating of water in an outdoor swimming pool in combined systems, the TS300 collector series or TS330 horizontal collectors.
● in devices requiring heating to a higher temperature, for technological purposes and for requirements for higher energy gain in winter, the TS400 collector series. These collectors are especially suitable for year-round water heating in indoor pools.
● for water heating in outdoor seasonal pools without further use, we recommend using plastic solar absorbers Soladur S.
● direct heating of pool water in metal collectors is not permitted (risk of corrosion and rupture of the collector absorber by frost).
For reliable and long-term operation of the solar system, it is necessary to use a closed solar system with indirect heating. The collector must have a non-freezing heat transfer fluid that allows the system to be used all year round.
● The gravity system must include: an expansion vessel, a safety valve, a venting device and a filling system. The center of the boiler heat exchanger must be at least 0.5 m above the upper edge of the collector
● The pump system must include: a pump, an electronic controller, an expansion vessel, a safety valve, a venting device, a filling device and a heat exchanger in the solar energy consumer, a non-return valve in case the heat consumer is lower than the collectors.
The simplest solar water heating system consists of:
● solar collectors
● supporting structure of collectors
● solar installation unit
● electronic controller
● expansion vessel
● solar boiler
● insulated pipes.
● Self-propelled – gravity system has lower investment costs. However, its energy gain is 30% lower than with a pump. In our climatic conditions, its occurrence is problematic, because the solar system has a lower energy yield and additional problems or additional costs, so that the entry and exit of heated water in winter, for example during holidays, does not freeze.
● The pump system has higher investment costs but also higher energy gains. Its use is more universal, it can also be made as a multi-circuit system.
For hot water heating, we recommend 2 collectors with a 200 l solar boiler and accessories for a 2 – 3 family, then 3 collectors with a 300 l boiler for a 3-4 member family.
For heating, it is necessary to make an energy balance based on its result to design the number of collectors. With heating, it makes sense to think in houses with low heat losses, they must not be higher than the standard prescribed maximum for new buildings. It is necessary to use a low temperature heating system, e.g. underfloor or wall heating. For an approximate estimate, the collector area can be considered equal to 1/7 of the heated area.
For outdoor pool heating in combined systems, it is necessary to consider the collector area from 40 to 50% of the pool surface area, in year-round indoor pools located in non-glazed buildings, the collector area is approximately equal to the pool surface area. In this case, we recommend using vacuum collectors.
We recommend mounting the collectors on a roof oriented to the south – azimuth 180 ° with a slope of 45 °. For deviations from the stated azimuth of 180 ° ± 45 °, it is not necessary to correct the collector area. We recommend increasing the collector area for larger deviations.
The orientation of the collectors to the southwest is more advantageous than the orientation to the southeast, because the occurrence of mist in the afternoon is less frequent and the ambient temperatures are higher than in the morning.
We recommend the slope of the collectors to be the same as the slope of the roof. It is not necessary to correct the collector area within the roof pitch range of 35 ° to 50 °. For year-round use, the optimal inclination is 45 ° to 50 °, for mostly summer use 30 °, for mostly winter use 60 °.
Due to the operating temperatures and pressures in the solar system, only metal pipes may be used. Due to insufficient heat resistance, plastic pipes are not suitable in any version !!! We recommend using copper pipes that are optimal in relation to the life of the system. Steel heating pipes are also permissible, but galvanized pipes are not suitable because there are no zinc corrosion inhibitors in the heat transfer medium.
The extreme temperatures that can occur in a solar system with standard collectors are 180 ° C and vacuum collectors up to 230 ° C. For this reason, we recommend using thermal insulation from Therwoolin mineral wool or Aeroflex EPDM material for standard collectors. We recommend Therwoolin mineral wool insulation when using vacuum collectors.
After the expiration date (6 years), the heat transfer fluid is possible:
● Dispose of in an industrial waste incinerator
● hand over to a retailer for recycling