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Events and Exhibitions
expensive . On top of that , there is a hazard of ammonia leakage . But if you use an ammonia-based chiller , then the ammonia is confined to the chiller area only and glycol-based chilled water which at a sub-zero temperature can be pushed into the building safely as a win-win situation . The air-cooled ammonia chiller has a very good COP .
For bigger projects where multiple ( two or three ) megawatts of cooling are required for industrial process cooling , we offer water-cooled chillers which generally offer 4,5 , or 6 COP . However , water-cooled chillers use a lot of water and electricity since their condenser is a cooling tower . There is a solution whereby we can replace the cooling towers with ground water .
For instance , there was a big project done recently in Australia where a supercomputer is being cooled by groundwater . This is a reference point and encouragement for us to look into using groundwater and replacing the cooling tower .
For example , I ’ m currently working on a project in Johannesburg where we are using generators and an absorption chiller . If the condenser which is connected to the cooling tower can be replaced by a heat exchanger which is water-to-water , it gives better results . In this particular case , the cooling capex is nearly halved if we offer a ground water heat exchanger instead of a cooling tower . There is a 75 % reduction in electricity consumption , and no water bill when using ground water heat exchanger .
Many companies are coming up with heat recovery fresh air units similar to fan coil units , but it has got two fans , so the inside air is not mixed with the outside air . That ’ s why it is called the fresh air heat recovery unit . It will reduce by two or three degrees Celsius the temperature which is coming from outside . It has a three-layer filtration system for 99.99 % cleaning of particles , and an 80 % heat load reduction with a simple retrofit for a payback period of less than three years .
We are minimising the use of air conditioning – but using less requires a lifestyle change . We are used to living in open houses and being outdoors . Rather than getting into open individual houses , more and more apartment blocks are coming up . One reason for this is to reduce the electrical expense and be economical . RACA
“ The air-cooled ammonia chiller has a very good COP .”
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RACA Journal I September 2023 www . refrigerationandaircon . co . za