The hidden cost, or associated cost, is almost 11 to 12 times more expensive than the cost of the air conditioning unit itself. The worrying aspect is that very few engineers, owners or developers fully comprehend the associated cost – simply put, they only see the tip of the iceberg.
And the costs don’t end there. I mean, what about the cost to the environment, where each kW of electricity emits more than 0.6 kilogrammes of CO2 in the GCC. A split unit, typically running for 3,000 hours per year at an average consumption of 1.4 kW/tonne, emits more than 2.5 tonnes of CO2 into the atmosphere of our already suffocating planet!
My obsession with real-life measurement has always led me to monitor performance, and I would like to share with you the data for a typical month (May), which represents the average annual performance of air-cooled chillers. (For the purpose of collecting the data, I considered a utility-grade equipment, which gave an average performance of 1.41 kW/tonne.)…
The writing is on the wall and deserves a vibrant response. The process of coming up with new high-efficiency standards, with the consensus of the majority of the heavyweight manufacturers, is taking too long and has soft targets, which will not help in improving efficiency.
A subtext to the drama is the issue of refrigerants. I am deeply concerned by the sight of the high volume of refrigerants that are pumped into air conditioning systems and by the massive leaks that occur during their operational lifetime. To date, I have not seen technicians carrying a receiver tank along with the pump-out unit. I have also not seen any leak-detection system associated with these units. If that were not serious enough, how many of us have seen technicians using refrigerants to blow open a clogged drain line? In the West, a technician caught doing so would have faced prosecution; it is high time we adopted such stringent measures and also insisted that all technicians be certified or trained. We need to act, and with speed. The GCC region consumes more refrigerant than the entire continent of Africa or the sub-continent of India, and we need to see the volume of use come down by a substantial margin.
Overall, I hope we will start seeing an end to our addiction for air-cooled systems sooner than later. And I hope we get to see more stringent regulations leading to a marketplace populated with more efficient units, and to a situation where the maximum power demand is 100 watts per square metre for all residential and commercial buildings; that would, in turn, hopefully compel the designer to optimise other system components in the house. For example, a 1.6 kW/tonne and efficient design of 40m2/tonne would translate to 40 watts/m2 for the air conditioning system, leaving only 60 watts for the rest of the components (appliances, receptacles, lighting, water heating, etc.), which would force the designer to use solar hot water heating and gas cookers, and reduce the lighting density as an example.
George Berbari is the CEO of DC PRO Engineering. He can be contacted at firstname.lastname@example.org
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