Flat Plate Solar Panels
High Efficiency Flat Plate Solar Collector
A flat plate collector consists of a thin absorber sheet (of thermally stable polymers, aluminum, steel or copper, to which a black or selective coating is applied) backed by a grid or coil of fluid tubing and placed in an insulated casing with a glass or polycarbonate cover. In most cases on newer designs, fluid (usually water/antifreeze dilute but sometimes concentrated antifreeze) is pumped through the tubing (as shown in diagram above) to remove the heat from the absorber and to transport it to an insulated water tank. Some panels have a completely flooded absorber consisting of 2 sheets of metal stamped to produce a circulation zone. Because the heat exchange area is greater they may be marginally more efficient than traditional absorbers, however, they contain more water which must be heated.
As an alternative to metal collectors, new polymer flat plate collectors are now being produced in Europe. These may be wholly polymer, or they may be metal plates behind which are freeze-tolerant water channels made of silicone rubber instead of metal. Polymers, being flexible and therefore freeze-tolerant, are able to contain plain water instead of antifreeze, so that in some cases they are able to plumb directly into existing water tanks instead of needing the tank to be replaced with one using heat exchangers. By dispensing with a heat exchanger in these flat plate panel, temperatures need not be quite so high for the circulation system to be switched on, so such direct circulation panels, whether polymer or otherwise, can be somewhat more efficient, particularly at low light levels.
Although they may look very similar, the technology within flat plate panels can vary quite considerably (unlike the evacuated tubes which use the same principal despite the design). Flat plates are still the more common type of solar water heating panel, although the benefits of evacuated tubes are fast being realised. Flat plates are most efficient in direct sunlight. For sunny climates they are an ideal option and tend to slightly outperform evacuated tubes.
Navitron’s high efficiency flat plate collectors are designed and manufactured by Solar Technologie International GMBH in Germany. STI has more than 20 years of experience manufacturing solar thermal collectors as well as performing continuous research and development to further improve their products. Their own industrial production ensures the extremely high quality of the collectors.
What makes the FP range stand out among other flat plate collectors is:
The serpentine absorber in the high-performance collector FKA allows the easy hydraulic interconnection of the collectors. The integrated high-performance manifold supplementary improves the heat transfer and permits the modular extension of the collector fields.
Furthermore the self-draining meander absorber allows the use of Drain Back Systems.
The absorbers are produced fully automatically in the ultrasonic welding machine. This modern welding process ensures a strong and extensive connection between the absorber plate and the tube whereby the best heat transfer is guaranteed. Moreover, constantly high output can be achieved during the collector’s whole working life.
The usage of pure materials in the absorber production will prevent corrosion, as it may occur while using different metals (e.g. copper and aluminium). The absorber is constantly exposed to high temperature fluctuations. Due to the use of pure metals in the absorber can rule out a mechanical strain because of differential extension (bimetallic effect), as it may occur with mixed material (e.g. copper and aluminium) can be prevented.
The vacuum coating process of the absorber plate is – in contrast to other methods – emission-free, non-harmful and requires about 10 times less energy than conventional manufacturing methods. In addition, the vacuum coated absorber plate is 100 % recyclable and can be put into the raw material system without any problems.
The coating is wear- resistant and non-corrosive and therefore a guarantee for constantly high output during the working time of the solar collector.
- Suitable for pressurised systems
- Solar Keymarked for RHI
- Can be used in all climates
- Copper absorber for rapid heat transfer
- Highly selective vacuum coating interpane
- Hail resistant, shatterproof solar glass
- Aluminium casing
- Easy plug-in installation for mounting on the roof or at ground level (requires mounting kit)
- Maintenance free
- Suitable for high pressure water (up to 8bar / 116psi)
- Collectors may be connected in series to increase water heating capacity
- Ideal for commercial solar water heating applications
- Expected Lifetime >25years
- BSEN 12975 Approved
The collector can be installed easily into the roof. The prefabricated sheet metal flashing forms an aesthetically pleasing look and meets all requirements concerning impermeability, simple installation, harmonious integration as well as ventilation of the collector field. The installation onto the roof is carried out with stainless steel roof clamps that are easy to install and are effective even with high snow and wind loads. There are suitable roof clamps for all tile and slate types. The prefabricated roof lead is easy to install and provides a pleasant overall finish. In addition to that, a special profile permits the fast installation of the collectors. Specially designed expansion joints are used for a secure connection of the collectors between each other. The hydraulic concept with continuous manifolds permits easy running of the tubes and enables the installation of potentially infinite collectors. The collector connection is resistant to thermal expansion, pressure fluctuations, movement of the substructure or foundation.