32 www. refrigerationandaircon. co. za RACA Journal I January 2026
PROJECT project
Lydenburg, adds:“ When Lydenburg High School set out to cut down its electricity use, six companies lined up with competing proposals. After careful evaluation by both the school board and an independent electrical engineer, one solution stood out: the MD heat exchanger.”
Unlike conventional systems, the MD heat exchanger offered two decisive advantages – efficiency and ease of maintenance. For a boarding school with high hot water demands, this was critical.
A standard 200l geyser with a 4kW element consumes around 18 amps. In comparison, the MD heat exchanger slashes this requirement to just 2.9 amps by operating at 700 watts. The result is dramatic power savings – something that was confirmed not only by internal testing but also through the independent audit.
“ I tested it myself, but to remove all doubt, we brought in an independent auditor who verified the numbers. The savings are real,” emphasises Schwan.
The aim of the first phase of the project – designed as a pilot, involved installing 10 heat exchangers – was to test ease of installation, monitor performance and validate the savings before scaling up.
The outcome exceeded expectations. Installation was straightforward, requiring no specialised skills beyond standard geyser or air-conditioner fitting. Maintenance proves equally simple: the MD heat exchanger avoids the use of sensitive PC boards, which are prone to failure during frequent municipal power cuts.
“ With this system, you eliminate the risk of burnt boards. This means if one technician moves on, another can step in without difficulty. Everything is standard and locally available.”
With the pilot deemed a success, the school board is preparing to install 27 additional units in the next phase, before rolling out across the full campus of 80 to 84 units. The cost-benefit analysis and verified data convinced decision-makers that the system will pay for itself within a short period.
“ This isn’ t just another minor tweak on an existing product, it’ s a genuine innovation. For me, it’ s a‘ wow’ factor,” says Schwan.
While the Lydenburg project showcases the system’ s performance in an institutional setting, the MD heat exchanger is also well-suited for households and small businesses. It can be retrofitted onto existing geysers, avoiding the need for costly replacements.
AN INDEPENDENT TEST: MARKING THE RESULTS Theo van Wyk, owner of ENFENERG, oversaw the trial at Lydenburg High School, which compared a traditional 3kW geyser with a heat pump / exchanger system demonstrating how heat pump technology can slash electricity bills and reduce peak demand.
The results were striking. A conventional geyser drew up to 18 amps, while the heat pump used just 2.9 amps.“ That translates to savings of about R1 800 to R1 900 per geyser every month,” Van Wyk explained. With roughly 80 geysers on campus and a monthly electricity bill exceeding R420 000, the potential for cost reduction is significant.
The unit tested achieved a coefficient of performance( COP) of around 4.1, meaning it delivered more than four times the heating compared to the energy it consumed. In practice, the system captures ambient heat and transfers it into the geyser via a refrigerant gas, rather than generating heat directly through
32 www. refrigerationandaircon. co. za RACA Journal I January 2026