› Benefits of modern refrigerants
As they hardly need any electric power, thermally driven chillers reduce the output of carbon dioxide significantly.
Owing to their ideal cooling characteristics, chloric refrigerants, so-called CFCs (chlorofluorocarbons), used to be the primary choice for use in compression chillers. As it turned out, however, these CFCs are harmful to the environment as they damage the ozone layer and accelerate the greenhouse effect. Their harmful effects were the reason why these refrigerants were banned or restricted in their use to a significant extent and replaced by refrigerants containing HCFC. These modern refrigerants do not harm the ozone layer at all or only to an insignificant extent.
Despite their lower potential of depleting the ozone layer, these modern refrigerants are also categorized as strong greenhouse gases. The term GWP (global warming potential) is used to assess the greenhouse effect and is related to 1 kg of carbon dioxide over a time span of 100 years. For instance, the refrigerant R134a has a global warming potential that is 1,300 higher than that of CO2. The refrigerants in chillers most commonly exits through leaks or is lost during recycling. On average, the leak rate of compression chillers is 8% of the filling capacity per year.
In contrast, thermally driven chillers operate on environmentally friendly refrigerants. Thermally driven chillers use either the natural refrigerant ammonium or pure water.
The distinguishing feature of conventional, electrically driven chillers is their significant electrical power consumption.
As approximately two thirds of all processes taking place in power plants around the world still rely on the combustion of fossil fuels such as coal, oil and gas, this power consumption is linked to the output of the greenhouse gas carbon dioxide.