Frequently asked questions:
Heating water with solar energy from the sun is the most cost-effective technology in South Africa.
Save money – A SunTank solar geyser correctly sized can save you as much as 50% of your total monthly electricity bill and 80% of your water heating costs. The pay-back on your investment is less than 2 years, leaving thousands of Rands in your pocket, for many years thereafter.
Be independent – With a SunTank solar geyser you can still have hot water during load-shedding and power cuts. Electricity rates increase will have a minimal effect on your monthly hot water bill.
Go Green – Solar heating is clean energy, no pollution, no harmful impact on climate change and global warming.
The SunTank geyser system comprises of a solar water tank and solar heat collector panels.
The glazed panel consists of a black copper absorption plate welded onto a copper pipe manifold. The manifold is placed in an aluminium insulated frame and covered with a 4mm, hail resistant tempered glass.
The sunlight energy goes through the glass and when it hits the absorption plate it converts into heat. This heats the fluid in the manifold pipes that then circulate to the tank. The circulation can be either natural, thermosyphon or forced with a pump.
In frost areas the fluid in the manifold is glycol antifreeze that circulate to the tank’s double-jacket heat exchanger. In non-frost area it is the water in the tank that circulate in the panel.
The circulation between the panels and the tank carry on right through the hours the sun is shining. At the end of the day, the hot water is stored in the insulated tank ready toward be used at bath time.
SunTank solar geyser are also equipped with an electrical heating element as a
back up, controlled by a thermostat that could automatically switch to top-up if the sun radiation was insufficient on a cloudy day.
A correctly sized solar geyser will maximise the benefit that can be derived by solar. You should choose the largest system you can afford or that your north-facing roof space allows. Existing electrical geysers of 150L shouldn’t be a used as a benchmark as they are repeatedly heated by (costly) electricity throughout the day.
In essence, the size of the solar storage tank should be big enough to provide your hot water requirements in a 24-hours cycle.
The number of people in your household and their hot water consumption habits determine the size of the SunTank system that you would need. A minimum of 50L per person per day should be the rule-of-thumb. A 300L SunTank is the most popular system in an average typical family house.
SunTank systems are designed to bring the water to around 50ºC -60ºC degrees in 6 hours of direct sun and to supply hot water 24/7, 365 days a year.
During the daytime, the geyser is heated by the sun and is stored in a B-rated insulated geyser that can retain the hot water overnight.
During cloudy conditions, SunTank’s standard electrical back up could be activated to ensure a constant supply of hot water.
SunTank’s flat-plate collector panels are covered with a hail resistant tempered glass that is tested by SABS.
In frost area, SunTank recommends the Indirect solar geysers where the tank is made with a heat-exchange jacket and the panels are filled with antifreeze glycol heat-transferred fluid.
This is the only 100% safe technology to prevent frost damage to a solar geyser system.
The maintenance of a SunTank system is minimal and should take place periodically. It includes restoring the heating performance in an Indirect system through the topping up of the anti-freeze fluid. In a Direct system, flushing potential dirt and sediment out of the panels should be carried out. At the same time when these performance restoring activities take place on the panels, the Sacrificial anodes in the tank are replaced.