Choosing a solar water geyser is not a simple process. Although two households may have the same amount of dwellers, hot water usage can differ greatly.
The first step in choosing a solar geyser is choosing what kind of solar geyser would suit your needs. The most common types of solar geysers include direct systems, indirect systems and evacuated tube systems.
Direct systems
Direct systems usually consist of one or more solar panels or evacuated tubes. Water is pumped into the solar panels, where it gets heated by the sun and stored in a geyser. Although these systems are reasonably effective, they tend to have a shorter life span. Chemicals in water erode the panels, pipes and geyser and parts need to be replaced fairly often. The water can also freeze in colder weather, resulting in cold water and damage to the system.
The map below illustrates which areas in South Africa are affected by frost from time to time. Direct systems wouldn't be suitable in these areas.
Indirect systems
Indirect systems also consist of one or more solar panels or evacuated tubes. Instead of pumping water into the panels directly as one would with a direct system, an anti-freeze substance circulates through the panels.
Once the liquid inside the panels is hot, it flows to the geyser. The liquid then either circulates into a sleeve that is fitted over the geyser or into copper pipes inside the geyser, heating the water. The copper pipes are a less effective way of heating the water because only a small volume of water comes into contact with the pipes at any given time. The pipes also allow less room for water, meaning a 300-litre tank will have less than 300 litres of water due to the presence of the pipes.
Indirect systems have a longer life span, because the anti-freeze is non-corrosive. It also retains heat longer and can’t freeze, even in the coldest conditions.
Direct or indirect systems with evacuated tubes
Although evacuated tubes can heat water up to boiling point, the excessively hot water can create too much pressure in the geyser, resulting in damage. Evacuated tubes are also susceptible to hail damage.
When choosing a product, look out for the following:
Heat retention
Heating water is only one of the tasks of a solar geyser. Retaining the heat generated through sunlight is another important factor, not only at night, but also in spells of bad weather.
Solahart systems have a double ceramic lining that insulates the heat. A Solahart solar geyser will only lose 5°C a night when the outside temperature is 0°C.
Solahart
With over 25 years' experience in the solar water heating industry in Southern Africa, Solahart has become the obvious choice in solar geysers for many households.
Solahart was the first distributor of solar geysers in the country to be awarded the SABS mark of approval. Our solar geysers are subsidised by Eskom, meaning that our clients get up to R4 917 cash back when they purchase our solar water heaters.
By installing a Solahart solar water geyser, our clients are not only assured of hot water no matter what Eskom gets up to, they also do their part for the environment.
Using solar energy means you can reduce your water heating costs by between 50% and 90%, depending on the unit, the installation and where you live. That means you'll use up to 90% less electricity when on heating water when you install a Solahart solar water geyser.
Products
Households can benefit from either a 180-litre Solahart solar geyser or a 300-litre system. The size of the Solahart solar geyser is determined by various factors, including the amount of people in a household.
In keeping with the highest international standards, all Solahart dealers and installers have received formal training, ensuring only the best installations and after-sales service.
Click here to view our range of Solahart solar water heaters.