Solar Water Heating
Among our range of Geyser products, we at A+E Solar Solutions are distributors of W.E. Geysers.
Since 1997, W.E. Geysers have been in the water heating industry.
Focusing mainly on domestic electric water heaters, their mission statement was clear and simple from the onset.
Produce products of the highest quality which are more technically advanced than competitors.
Considering South Africa's harsh and diverse water conditions, something more advanced had to be employed to reduce corrosion.
Old technologies required maintenance because the sacrificial anodes needed regular replacing.
PEX (cross-linked polyethylene) displayed the characteristics required for improved durability, heat resistance and resistance to chemicals.
PEX also has proven performance in the plumbing industry.
To date, W.E. Geysers have manufactured close to half a million units.
PEX has proven superiority over the traditional methods for preventing corrosion, thus remaining relatively maintenance free.
This technology and experience have now been employed in our range of solar water heaters under the SOLARTHERM® Brand name.
Solartherm® tanks are available from 100 through 350-litre tanks.
The need for a system resistant to extremely cold and poor water conditions has led to the development of an indirect cylinder with a removable heat exchanger.
This direct model has been available for more than a decade.
All our Solartherm® and Duratherm® products are manufactured under ISO-9001 conditions with specific materials.
This enables us to offer a 10-year warranty regardless of the incidental water conditions on site.
In the direct solar system, the water is heated by circulating water from the storage vessel through the solar panels.
This can be done naturally via thermosyphon convection or directly via an electric pump.
The system is simple and cost effective, however, it must be noted that the pressure in the storage cylinder
will be transferred to the panel which makes this unsuitable for certain configurations.
Should this system be selected in low-temperature areas (below zero in winter: Sutherland and mountainous areas such as Drakensburg, Maluti and other cold areas), simple ways to control panel freeze has been adopted.
In coastal regions and most other parts of South Africa, direct systems are highly suitable without the need for freeze control.
Whether or not a panel freezes also depends on to a large degree on the panel quality(insulation, air gap etc).
Furthermore, the integrity of the installation, the insulation of the pipes (particularly copper pipes etc), could be responsible for system freeze.
A direct system should not be installed in areas where the water contains high levels of dissolved solids.
Depending on the severity of the water condition problem, the panel may become clogged in the short term.
High-level water solutes will rapidly render water systems ineffective.
In a direct system, the geyser has no influence on the performance of the system other than providing reserve heat via an electrical element.
The element simply functions as part of a hot water storage tank system and is thus used less frequently.
This allows for increased system durability and reliability.
Why do we need an indirect system?
Both direct and indirect systems find their uses and acceptance in the market and offer the customer various options.
However, indirect system heat exchanger contain a food grade glycol (anti-freeze) solution, which therefore prevents the panel from freezing up or blocking, and increases the boiling temperature of the transfer fluid.
By being able to select a glycol mix as transfer fluid, the problem of lime and/or other build-up is prevented.
Indirect systems are more complex due to additional components.
There is a heat exchanger, either comprising a sleeve on the outside of the tank or an apparatus inside the tank to transfer temperature from the panel to the water inside the geyser. These components are mostly manufactured using copper or stainless steel.
Panel size/performance must be matched to the capacity of the storage tank in such a way that the system works efficiently.
In all the tests done at the SABS by various solar companies who elected to have their systems tested in conjunction with a Solarthermal® geyser, test results show high to very high degree of efficiency.
Efficiency levels are expressed as a "Q" factor and represent the basis by which the Eskom rebate system is calculated.
W.E. Geysers produce 2 types of indirect geysers, the "Standard" type heat exchanger, and the "Trumpet" type heat exchanger.
In both cases, the heat exchangers can be replaced or repaired in the event of failure.
The "Standard" type geyser was designed to accommodate passive (Thermosyphon) and actively pumped operation.
The "Trumpet" type geyser was designed for active (pumped) operation only.
The installation of active indirect systems, as well as their maintenance, is more involved than passive indirect systems or active/passive direct systems.
The glycol mixture should be replaced at least every three years.
Active indirect systems can be circulated by either a 220/230 Volt pump or a 12V pump operated via a PV (Photovoltaic) panel.
During the day the PV panel acts as a battery charger. The battery, in turn, operates the pump and supplies power to the system controller.
Indirect systems are more expensive than direct systems and active systems are more expensive than passive systems.
GUIDELINES ON SELECTING THE RIGHT SYSTEM FOR YOU!
 What are the climate conditions in your area?
 What are the water conditions in your area? If necessary have it tested.
 How much hot water is used by your family members per day?(storage criteria)
 How much are you prepared to invest in a Solar thermal system?
 What are your performance expectations?
 What electricity saving payback period is acceptable to you?
 What life expectancy do you anticipate from the system?
 Are you concerned about the aesthetics of your roof/home if installing an external solar system?
You may prefer the geyser visible(on the outside) or hidden.
 Would a heat tube or flat panel be more suitable?
You may wish to research it or simply get professional advice from A+E solar solutions.
 Once you have selected a suitable system, enquire before installation regarding Eskom rebate offers on your intended system.
 Opt to get everything in writing before placing your final order.
It is advisable to investigate all these options before deciding on an installation to ultimately ensure your peace of mind and satisfaction with the final result.
The roof area for Solar panel installation should be free from obstructions. Efficiency of the system relies on various on site factors(shade from trees, other buildings, etc).
* For further information, you are welcome to contact our technical department.