All images supplied by Cool-Air. www. refrigerationandaircon. co. za 29
PROJECT
TURNING HOT WATER INTO A LEARNING OPPORTUNITY
By Eamonn Ryan
MD Airconditioning and Cool-Air have teamed up at Lydenburg High School to prove that hot water doesn’ t have to come with a scorching electricity bill. Their innovative heat exchanger project is giving students a real-world lesson in science, savings and sustainability – no homework required. project
In Lydenburg, Mpumalanga, a significant energy-saving initiative is underway that promises to redefine hot water solutions for large institutions. Derick Gomez, director of MD Airconditioning, is at the forefront of this project, supplying and overseeing the installation of 80 cutting-edge heat exchanger units at the largest school in the area, aiming to drastically reduce its electrical consumption.
While this project is fundamentally about providing efficient hot water, it achieves this through an innovative application of air-conditioning technology and equipment.
The project emerged from a critical need to curb the substantial energy demands of the Lydenburg High School ' s dormitories, which house numerous geysers providing hot water for students and staff. MD ' s heat pump technology was chosen over competitors, including well-known combo units, primarily due to its superior efficiency, competitive pricing and costeffective maintenance, he says. " He won the tender in terms of price and the efficiency of the product," Gomez notes, referring to his client, the local air-conditioning contractor Cool-Air, which handled the installation. The entire Lydenburg community is keenly observing the outcome, as the school serves as a central hub for many families.
At the heart of this project lies Gomez ' s proprietary heat pump design, an innovation he developed several years ago. Unlike conventional systems that pump water from the geyser to an external condenser for heating, Gomez ' s technology takes a different approach. It utilises a standard air-conditioning unit ' s refrigeration cycle to heat the water directly inside the geyser tank.
" It actually is an air-conditioning unit in that you use its refrigeration cycle to heat the water in your tank," Gomez explains. This means a normal 9 000BTU or 12 000BTU airconditioning condenser is paired with a specially manufactured heat exchanger. The existing electrical element and its flange are completely removed from the geyser, and the heat exchanger is fitted in its place, transforming a conventional geyser into a highly efficient heat pump system.
The advantages of MD ' s system are multifold. With an impressive Coefficient of Performance( COP) of up to 5.6 – this project achieves 4.1 according to live readings as the test
RACA Journal I January 2026
The simplicity of the design also means fewer moving parts. was done coming out of winter with cold tap water affecting performance – it stands out against competitors. From a cost perspective, the supply and installation of one of these units is less than half of other heat pump geysers on the market, he says.
Beyond the initial outlay, the long-term savings are substantial. A key benefit is the reduced repair and maintenance cost. Should any component fail, a standard air-conditioning condenser is cheaper and more readily available to replace than parts for more specialised, integrated heat pump geyser units. The energy savings are particularly compelling for a large institution like the school. Traditional geyser elements typically consume 3 – 4kW of electricity. In stark contrast, MD ' s heat pumps operate at a mere 700 – 800W. This dramatic reduction translates into immense monthly electrical savings for the school. Gomez estimates that with his product,“ customers typically see their investment recouped within a remarkably short period, usually a year and a half or less ".
All images supplied by Cool-Air. www. refrigerationandaircon. co. za 29