Solar Water Heating

Make sure you understand what solar system to install.

Step 1 –  You will have to select between a Direct system and an Indirect system. The decision depend on regional climate and/or the water quality in your area.

Step 2 –  You need to decide between a Thermosyphon system and a Split pumped system. The decision depend on your personal preference for aesthetics rather than cost and efficiency or visa versa.

Step 3 –  You may also decide between a Complete solar system and a Retrofit solar conversion. Your budget may dictate your decision. 

• Direct systems are recommended for frost-free locations where the ambient temperature never falls below 5°C and where the water quality is good. Direct systems are suitable for all our coastal areas.
• Direct solar water heating systems transfer water through the thermal collector to the geyser and from there to point of use.
• Direct systems can be used with solar collector panels or evacuated tubes.

• Indirect systems are used in locations where frost occurs and where the ambient temperature falls below 5°C in winter.
• Indirect systems are also recommended where the water quality is poor.
• In an indirect system water is heated indirectly. A water and propylene glycol mixture form the basis of the liquid in an indirect system.  The liquid is circulated through the solar collector panels transferring solar energy into the heat exchanger and in turn heating the water in the geyser.
• Indirect systems are recommended for inland area’s.

• Thermosyphon water heating systems work on the natural principle that hot water rises and cool water sinks. As water is heated it expands, whilst gravity pulls down the relatively heavier cool water molecules. The warmer molecules rise up.
• During the day water in the solar collector is heated by the sun. As the water heats up, it rises pushing up into the tank installed higher than the collector. Cooler water at the bottom of the geyser is then pushed down to the bottom of the solar collector where it is further heated. Thereafter the cycles will continue throughout the day to heat the stored water in the geyser.
• Thermosyphon solar water heating systems are normally installed on-roof, but can be installed in-roof where the pitch roof is more than a 34 degree angle. 

• A split pumped solar system is where the geyser is installed below the solar collector panel and where a circulation pump and an intelligent system controller is required. Hot water is circulated from the panel to the geyser and cold water from the geyser to the panel for further heating.
• The intelligent system controller monitor temperature differences between the panel and the geyser and regulates pump instructions accordingly.
• The split pumped system is a little less efficient than the thermosyphon system due to the longer transfer distance between the collector and geyser. Resulting in a lost of heat due to transit. 
• Split pumped solar systems are still a favourite in South Africa due to its aesthetics with only the solar collector visible on the roof.
• Split pumped solar systems are more expensive due to the additional cost of the circulation pump and the system controller required.
• Split pumped solar systems will require more maintenance than a thermosyphon system over time due to more working parts and electronics involved.

• The solar retrofit conversion system is specifically designed to convert an existing high pressure electrical geyser into a direct solar water heating system.
• Most 150lt and 200Lt electrical geysers can be converted into a solar water hearing system.
• A retrofit system is suitable for all climatic conditions (frost and frost free locations) and works on the pump circulation method with a flat plate collector or evacuated tubes.
• Heat loss in a retrofit conversion will be higher than the heat loss in a solar geyser due to the fact that a solar geyser is better insulated.
• A solar retrofit conversion will be cheaper than a complete solar system due to the fact that the existing electrical geyser is used.
• The retrofit conversion system will function on the same basis as a split pumped system where the geyser is installed below the solar collector panel and where a circulation pump and an intelligent system controller is required to circulate hot water from the panel to the geyser, and cold water from the geyser to the panel for further heating.

• Kwiksol Direct geysers with a 5-year product warranty
  100Lt, 150Lt, 200Lt & 300Lt Direct solar geysers
• Kwiksol Indirect geysers with a 5-year product warranty
  150Lt, 200Lt & 300Lt Indirect solar geysers
• Xstream Direct with a 7-year product warranty
  150Lt & 200Lt Solartherm Direct solar geysers

Solar panels/collectors

• Kwiksol collectors – with a 5-year product warranty 2sqm, 2,2sqm & 2,5sqm Panel collectors
• SunScan collectors – with a 10-year product warranty
• SolarSeven indirect collectors – with a 5-year product warranty

You can still save on energy cost without installing solar, the following are good examples. It only require some discipline.

• Showers use less water than baths
• Aerated shower-heads use less water than normal shower-heads.
• Lower the temperature of your geyser from 70 degrees to 60 degrees, or even 55 degrees.
• Insulate all the hot water pipes leading from the geyser to reduce heat losses.
• Switch off your geyser during daytime or install a digital timer or geyser wise controller to manage heating temperatures according to your needs.