Solar Water Heating
Replacing your existing number of conventional geysers with solar geysers will reduce your hotel energy bill for hot water by up to 50%. We recommend the Kwiksol and Solarhart systems. There are two main factors to consider when purchasing a solar water heating system; water quality and prevalence of frost in your area. Both factors are relevant to optimising the performance of a solar water heating system for your hotel, lodge or B n’B.
There are two types of systems; a direct system and an indirect system:
The water circulates through collector panels in a direct system. To function properly, the ambient air temperature must not fall below 4˚C and the water quality must be good. The open/direct system is not generally suited to the frosty winter conditions and high water mineral quality in our country (South Africa). In this system the solar geyser is placed inside the household roof causing potential heat loss in the piping between the collector panels and the geyser.
In an indirect/closed system, the household water does not circulate through collector panels. Instead heat is transferred indirectly without coming into contact with the water via a heat exchange fluid in the collector panels. The collector panels and the geyser are situated on the roof right next to each other resulting in minimal heat loss. The indirect/closed system is well suited to our climatic conditions and inconsistent water quality (South Africa).
What you need to know:
- Estimated savings on energy bill for hot water: up to 50%
- Estimated cost for system and installation: From R12000.00 Excl Vat for a 100 litre system and up to R45000.00 Excl Vat for an imported 300 litre system upwards depending on your hot water needs
- Government (Eskom) rebate: there is no rebate currently in place
- Payback period: between two to three years depending in consumption
- A back up element (electrically powered) ensures the balance of supply and ensures that you never run out of hot water. This is typically controlled by a relay timer which can be programmed to suite your hotels daily hot water needs
- Evacuated tubes absorb 90% of the suns radiation and have a quicker heating response time. These systems require very little maintenance and are generally the cheaper option.
- Flat plate collectors absorb 75% of the suns radiation. Flat plate collectors are suited for areas where frost is prevalent. They require the glycol or antifreeze agent to be serviced every 12 to 18 months. Flat plat collectors have a longer life span (20 years) compared to evacuated tubes
- Solar water geysers have a much longer lifespan (up to 20 years) than a conventional geyser (usually 5 years)
- Heating still takes place on a cloudy day because the system relies on UV rays which penetrate clouds in overcast conditions
- 100, 150, 200, 250 and 300 size options are available depending on make. Size choice is dependent on household consumption. A 200 litre system will typically meet the demand of a four person household.
- Ideally, the system should be installed in a northerly orientation on the roof
- In a direct system, where the geyser and solar panel are installed separately from one another, they must not be more that 5 meters apart from one another
- Quality: it is strongly advisable that you choose a system with SANS 1307, is SABS 400kPa approved and can be installed as a close coupled or split system. All Green Your Home recommended suppliers have a warranty agreement on their products ranging from 5years for locally manufactured systems to 10 years for imported systems
- Many manufacturers/importers do not necessarily offer an installation service. Instead, manufacturers deal with the trade and recommend a pre-approved installation company. Make sure that the installations comply with SANS 10106 Solar Water Heater Installation Specifications and include all the required installation components
- Reputable suppliers like Kwiksol offer financing