What to consider in a solar geyser

girl washing dishes doing chores domestic life with a solar geyser

You’ve decided to go the eco-friendly route and install a solar geyser. Installing a solar geyser in your home means that you are contributing to the solution. The solar technology is used widely overseas. South Africa is now taking advantage of the ample sunshine. If you’re looking to buy and install a solar geyser but don’t know where to start this is the guide you need.

Here are a few factors you should consider before buying a solar geyser.

Indirect or direct system

Direct systems: these types of solar geysers are best for frost-free areas, allowing for the water to be heated directly.
Indirect systems: these types of solar geysers are best suited for homes that are situated in areas that experience frost. Indirect systems allow for the water to be heated through a heat exchange mechanism.

Tank size

The size of your tank is dependent on the number of people living in your home. Allocate 50 litres of warm water per person. In addition, budget an extra 50 litres of warm water for general domestic usage. With these calculations in mind, you’ll be able to estimate the tank size best suited for your home. A general rule of thumb is if your current traditional electric geyser is, for instance, a 150lt, then the solar geyser should be a 200lt.


South Africa is fortunate to experience an abundance of sunshine from the far north to the far south of the country and therefore the aperture areas of the solar absorbers (solar collector panels and evacuated tubes) do not have to differ by area. What is important though is that the current size aperture are is used with the correct size solar geyser. For example, a 150t solar geyser would use one 2m² solar collector panel or 12 evacuated vacuum tubes. In areas that experience extremely hot weather (+30°C), the water in the solar geyser can reach a boiling point. To alleviate this, a thermostatic mixing valve is included in the solar installation, which allows cold water into the system when the water reaches a preset temperature.

solar geyser double pane Kwikot productSplit and Close Coupled Systems

There are two types of systems, namely a Split Pumped System and a Close Coupled Thermosyphon System

Split Pumped System: the placing of the solar geyser at a lower level and away from the solar absorbers, such as in the ceiling or at floor level, whereby a pump is used to circulate the water between the solar geyser and the solar absorbers.

Close Coupled Thermosyphon System: the placing of the solar tanks outside on the roof and above the solar absorbers and the entire system is joined. The natural laws of physics apply whereby the hot water rises and automatically circulates between the solar geyser and solar absorber.

The above-listed products are just a few but important factors to consider before settling on a solar geyser. It’s essential that you consider geography, the number of people living in your home, and of course your budget.

Copyright © 2024 New Media, a division of Media24. All rights reserved.