RACA Journal February 2020 | Page 44

Projects COOLING WHILE SAVING WATER AND ELECTRICITY By Ntsako Khosa Despite its capital cost and the perception around using water for evaporative cooling, Baltimore Aircoil Company opted to install an adiabatic cooler at the Garden Centre in Cape Town that saved water and electricity. “ “The installation of the equipment and piping was completed by Mechanical Cooling and Maintenance; the piping connects the adiabatic units to the condenser coil of existing Trane RTHB chillers. It was mostly a smooth project with no significant problems encountered,” says the Cape Town representative of BAC, Duncan McIvor of Baltimo. GETTING IT RIGHT Although the supply of make-up water quality was a challenge and caused blockages with the solenoid valve, which would supply water to the precooling pads. “This issue was resolved by adding a strainer up-stream of the valve. There was a concern also around noise levels of the adiabatic unit. This was addressed by installing velocity recovery duct to the EC fans (AxiTop) to give the unit additional performance thereby allowing us to reduce the The current environmental situation in Cape Town tends to drive engineers away from specifying evaporative cooling equipment on HVAC applications, since during a water outage, no cooling will be possible, as well as the cost of water relating to the water usage of a fully evaporative solution. We cannot deny that it is thermodynamically impossible to be more efficient with a fully air-cooled solution compared to a fully evaporative solution. The adiabatic unit takes the best of both options, to create overall system efficiency with water saving,” says head of marketing and refrigeration, Garid Glenn. Commissioned in May 2019, the client specified Baltimore Aircoil to replace an existing open circuit tower and the tower should provide low water consumption, have the ability to maintain the same water temperatures as the original towers and provide free cooling capability to implement at a later stage. The Baltimore Aircoil adiabatic units installed in Cape Town. 42 RACA Journal I February 2020 www.hvacronline.co.za