RACA Journal I January 2026 www. refrigerationandaircon. co. za 33
PROJECT
resistance elements. This design avoids heat losses common in older systems and improves efficiency.
Van Wyk noted that the technology also reduces maximum demand charges. When hostel geysers often all switch on simultaneously during peak shower times, they drive up the school’ s load.“ If enough units are converted, the maximum demand will come down too – adding several hundred rand in savings per geyser each month,” he said.
At about R17 000 per unit, the payback period can be less than a year, with warranties extending five years. Beyond schools, Van Wyk sees value for households and estates using solar. By cutting geyser consumption, fewer panels and smaller batteries are required.
For Lydenburg High, the maths is compelling. Even converting half of its geysers could save R70 000 to R100 000 monthly.“ It’ s really a no-brainer,” van Wyk said.“ With these systems paying for themselves so quickly, the long-term savings free up resources for education rather than electricity.”
paired with the internal heat exchanger coil.“ That’ s why this combination is so efficient – it just moves heat, it doesn’ t need to create it,” Van Wyk concludes. RACA project
HOW THE HEAT EXCHANGER GETS TOP MARKS ON DELIVERING MORE HOT WATER FOR LESS POWER While traditional electric geysers rely on resistance elements to generate heat, a heat pump / exchanger works on a different principle: it moves heat rather than creating it.
“ The easiest comparison is to your household air conditioner or refrigerator. An element needs one watt of electricity for every watt of heat it produces. A heat pump, on the other hand, uses a small amount of electricity to shift heat from one place to another,” says Van Wyk.
In practice, the system pulls heat from the surrounding air. A refrigerant gas absorbs this ambient warmth, then gets compressed. That compression raises the temperature, and the hot gas is piped directly into a coil inside the geyser. The coil acts as a heat exchanger, releasing the captured heat into the water.
This design is different from older heat pumps, which pumped water to and from the unit.“ By taking the refrigerant directly to the geyser, we avoid those heat losses and improve efficiency,” Van Wyk explains. The result is a higher COP – the measure of how much heat is delivered compared to the electricity consumed.
The benefits go beyond efficiency. Because the hot refrigerant coil sits inside the geyser, the risk of limescale build-up is reduced compared to water-based systems, extending the lifespan of the equipment. Maintenance is simple: mainly cleaning or replacing the exchanger if efficiency drops.
There are performance limits: the higher the set water temperature, the harder the pump must work.“ Getting from 20 ° C to 60 ° C is straightforward. But pushing to 70 ° C is like driving at 160 km / h instead of 120 – it takes more energy.” Still, in normal use, the system consistently outperforms electric elements.
The simplicity of the design also means fewer moving parts. Essentially, it’ s an outdoor unit similar to an air conditioner,
“ I couldn’ t have asked for a better result, real savings obtained from a real-life working environment – really proud” – Derick Gomez.
RACA Journal I January 2026 www. refrigerationandaircon. co. za 33