RACA Journal I October 2026 www. refrigerationandaircon. co. za 13
HEAT EXCHANGERS
RECYCLING HEAT: HOW HVAC & R SYSTEMS CAN SLASH ENERGY COSTS
By Eamonn Ryan
As energy prices climb, commercial buildings are under pressure to do more with less. Founder of Mr Heat Pump, Roger Fawcett, and AI Hot Water Company power engineer Michael Carter, argue that the answer is already flowing through our plants: waste heat from air conditioning, refrigeration and boilers that can be captured, stored and reused to deliver hot water at a fraction of the cost.
business
Buildings with significant cooling and hot-water demands
– including hotels, hospitals, laundries, bakeries and data centres – spend heavily on boilers, chillers and VRF systems while rejecting large amounts of usable heat. According to Roger Fawcett and Michael Carter, recovering and reusing that energy represents one of the biggest opportunities for reducing operating costs in commercial HVAC & R.
Europe, where high energy prices have driven innovation in heat recovery, provides numerous examples. Carter points to a one-megawatt commercial laundry boiler where heat exchangers recover energy from both flue gases and hot effluent.
Carter explains that heat exchangers recover energy from flue gases and hot wastewater before transferring it to a large stratified thermal storage tank. The tank naturally maintains temperature layers, allowing different grades of heat to be drawn off as required while preheating incoming feedwater and significantly reducing boiler fuel consumption.
“ What makes this especially relevant to HVAC & R professionals is that air conditioning and refrigeration systems already sit at the heart of the opportunity. VRV and VRF systems in hospitals, hotels and offices are constantly moving heat from one place to another – pulling it out of occupied spaces and rejecting it to ambient through condensers. In many of those systems, the heat-recovery hardware is effectively already there; it’ s just not being fully exploited yet.”
Carter describes a project in a municipal office in Germany where a VRV system did double duty. The plant served as the building’ s cooling system, but instead of rejecting all of that heat outdoors, it captured it into hot-water storage tanks. When parts of the building were in cooling mode, the‘ waste’ heat became the energy source for over 400 showers for free.
Every refrigeration system has a hot side and a cold side, yet the industry has traditionally focused on the cooling while rejecting the heat. Carter argues that, with suitable heat exchangers and controls, condensers should instead be viewed as valuable energy sources capable of simultaneously producing chilled water and domestic or process hot water.
Founder of Mr Heat Pump, Roger Fawcett.
AI Hot Water Company power engineer Michael Carter.
© RACA Journal © RACA Journal
RACA Journal I October 2026 www. refrigerationandaircon. co. za 13