RACA Journal I January 2026 www. refrigerationandaircon. co. za 31
PROJECT
LEARNING FROM A PHASED ROLLOUT AND INDEPENDENT VERIFICATION The project commenced with an initial pilot of ten units, which were rigorously tested. To ensure complete transparency and to validate the performance claims, the school has engaged an independent electrical engineer – Theo van Wyk, owner of ENFENERGY – who has no affiliation with either MD Airconditioning or the installer Cool-Air. This third-party engineer meticulously took readings, measuring amperage and verifying the units’ consumption and performance. His report is provided below.
As Gomez asserts,“ These are readings from a live working project, highlighting the real-world, unbiased nature of this verification process, which contrasts sharply with controlled laboratory tests. Upon completion of this initial phase, factual data on energy consumption and savings became available, providing concrete evidence of the system ' s efficacy.” Gomez personally oversaw the installations in Lydenburg to ensure adherence to stringent standards.
The school project ' s fundamental objective was to mitigate excessively high electricity costs. After evaluating various options, including solar and gas, Gomez ' s heat exchanger system was selected as the optimal solution due to its superior energy consumption efficiency. It proved more cost-effective than current gas alternatives and significantly outperformed solar water heating. Gomez emphasises that traditional solar systems often fail to deliver consistent savings because their electrical elements activate during peak morning and evening hot water demand, when sunlight is absent, negating daytime solar gains. In contrast, his heat exchanger pumps offer consistent energy savings irrespective of sunlight availability. Furthermore, potential future scarcity and rising costs of LP gas in South Africa could further solidify the economic advantage of electric heat exchangers.
Addressing the Lydenburg climate, Gomez explains the fundamental principle behind his heat pump: it extracts energy directly from the ambient air and transfers this energy to heat the water in a geyser. This process leverages the existing‘ hot side’ of an air conditioning unit ' s refrigeration cycle. A key innovation in Gomez ' s design is the use of liquid refrigerant to heat the water, a technique he notes he was employing even before it became a trend in newer air conditioning technologies for longer pipe runs. The system uses R410a refrigerant.
Gomez strongly advocates for simplicity being the " height of sophistication ". By removing clutter – multiple controls, switches and sensors that increase production costs and are prone to breaking – his design gets " as close as we can to the law of thermodynamics ".
“ This minimalist approach is directly responsible for achieving the system ' s remarkably high 5.6 COP, contrasting sharply with typical air conditioning units( 3.8 – 4.8 COP) and even other heat pumps. This efficiency means that if the system is designed and installed correctly, it simply works, without the need for additional complex components.”
The inherent simplicity also means the system is adaptable. While its primary function is hot water generation, Gomez notes that with " a slight modification ", it could be used for cooling or air conditioning, showcasing its versatility.
A core tenet of Gomez ' s operation is his commitment to South African quality and local sourcing. While the outdoor condenser units are imported, the critical components of his heat exchanger are domestically sourced: the copper coil is made from South African copper manufacturer Maksal, and the stainless steel flange from South African 316 stainless steel. He acknowledges that these local materials are " a bit pricey, but it ' s quality ", a direct response to negative experiences with imported Chinese products that " didn ' t last " and showed signs of rust within their copper coils.
DESIGN PHILOSOPHY – LEARNING FROM THE BASICS Gomez reiterates the simplicity and effectiveness of his system: " We remove the elements and fit our heat exchanger – so there is no element whatsoever on the geyser. It ' s just a tank with a refrigeration coil."
He underscores several unique elements that make his product special:
• Element removal: directly replacing the geyser ' s element with his heat exchanger
• Liquid refrigerant: using liquid refrigerant for heating, which enhances efficiency
• Extended pipe runs: the system can accommodate outdoor unit distances of up to 15m from the geyser without needing to upsize the machine, unlike many other heat pumps that require upsizing beyond 7.5m or 10m
•‘ Inverter-like’ performance: the system starts with a relatively low amperage of around 2.9 amps when water is cold, and gradually increases as the water temperature rises, mimicking an inverter ' s efficiency without the added complexity. This principle is derived from the observation that submerging a running condenser in water causes its gas pressure and amps to drop
His background in air conditioning and refrigeration contrasts with the common trend of plumbers installing heat pumps. Gomez argues that plumbers are often unqualified to repair heat pump components like compressors or heat exchangers, leading to calls to refrigeration specialists when breakdowns occur. He observes a growing convergence between the plumbing and air-conditioning industries, especially as plumbing projects increasingly incorporate sophisticated air-conditioning technologies like his heat pumps.
POWER SAVINGS AT LYDENBURG HIGH: FUTURE LESSONS IN ENERGY USE Stefan Schwan, project manager and owner of Cool-Air in project
RACA Journal I January 2026 www. refrigerationandaircon. co. za 31