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RACA Journal : ISSN 1812-772X
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RACA Journal Publication www . refrigerationandaircon . co . za eamonn @ interactmedia . co . za
THE UNSEEN ENVIRONMENTAL COST OF AIR-COOLING TOWERS
In recent years , there has been a significant shift in the HVAC industry from water-cooled systems to air-cooled systems . This change is often touted as a more environmentally friendly solution due to the reduced water consumption at the building level . However , a closer look reveals a more complex picture , especially in regions where the primary source of electricity is coal-fired power stations .
Historically , water-cooled systems were the standard in HVAC projects due to their high energy efficiency and effectiveness . Over time , however , advancements in technology have led to the development of sophisticated air-cooled chillers , which are now more prevalent in new building designs . These modern air-cooled systems are easier to install and maintain , making them an attractive option for many developers .
The primary argument in favour of air-cooled systems is their reduced water consumption , which is particularly beneficial in areas facing water scarcity . However , this perspective often overlooks the broader environmental impact . Hence , in countries like South Africa , where most of the electricity is generated from coal-fired power stations , the energy required to operate air-cooled systems significantly increases the demand on these power plants .
You are not consuming water at the building , but you are passing on a much higher energy consumption to Eskom which now must burn more emission-producing coal on your behalf and evaporate the water on your behalf anyway . This means that while water usage at the site of the air-cooled system may decrease , the overall environmental footprint could be larger due to the increased coal consumption and associated emissions .
The Green Building Council and other regulatory bodies often award points to buildings that implement air-cooled systems for their lower water usage . However , this metric can be short-sighted , failing to account for the source of the electricity powering these systems . In regions reliant on coal-fired power , the shift to air-cooled systems may ultimately lead to higher overall water usage and greater environmental harm due to the energy-intensive nature of these power plants .
The debate over air-cooled versus water-cooled systems is reminiscent of discussions surrounding electric vehicles ( EVs ). While EVs are praised for their zero tailpipe emissions , their environmental benefits are heavily dependent on the energy mix of the electricity grid . In regions dominated by coal-fired power , the carbon footprint of
charging an EV can be significant . This highlights the need for a holistic approach to environmental impact assessment , considering the entire lifecycle and energy sources involved .
The shift towards air-cooled systems and the growing adoption of electric vehicles underscore a critical need for comprehensive evaluation criteria that consider both direct and indirect environmental impacts . Policymakers and industry leaders must ensure that the solutions promoted as ' green ' genuinely contribute to sustainability when viewed through a broader lens .
While air-cooled systems offer certain advantages , their environmental superiority over water-cooled systems is not clear-cut , especially in coal-dependent regions . A more nuanced approach , considering local energy sources and overall environmental impact , is essential for truly sustainable HVAC and energy practices .
• Energy consumption and water usage in HVAC systems : Studies have shown that while air-cooled systems reduce on-site water consumption , the increased energy demand from coalfired power stations can negate these benefits . For example , research published in the journal Energy and Buildings highlights the trade-offs between water usage and energy efficiency in different cooling technologies .
• Coal-fired power plants and water usage : A report by the Union of Concerned Scientists details how coal-fired power plants are among the largest industrial users of water , using vast amounts for cooling purposes . This underscores the indirect water consumption linked to increased electricity demand from air-cooled systems .
• Lifecycle assessment of electric vehicles : A comprehensive study by the International Council on Clean Transportation ( ICCT ) emphasises the importance of the energy mix in determining the true environmental impact of electric vehicles , drawing parallels to the need for a holistic view in assessing cooling systems .
By critically evaluating the full environmental costs , including the energy sources and associated water usage , we can make more informed decisions that truly benefit the planet . RACA
Eamonn
REFERENCES : https :// www . emerald . com / insight / content / doi / 10.1108 / IJBPA-02-2021-0019 / full / html
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