Global Warming

Environmental impact – energy and carbon emissons


Currently, 10% of greenhouse emissions and 16% of the UK's electricity consumption are estimated to be attributed to the use of refrigeration, air conditioning and heat pump equipment according to the Carbon Trust. 

A good example of such an area is the food industry where refrigeration energy use is high - the food industry is responsible for 12% of the UK’s industrial energy consumption and uses over 4500 GWh/yr of electrical energy. Considerable potential exists to reduce energy use within the food industry by improving the overall efficiency of refrigeration processes and to develop systems that fully utilise resources.

Another example is domestic heating - it is estimated that if 1% of boiler replacements converted to heat pumps which use refrigeration technology, displacing gas condensing boilers, this would be equivalent to 3.7 million tonnes of CO2 being saved in one year.

Reducing its environmental is an important challenge for the sector and its essential users.  This issue is being addressed with many energy saving innovations and environmental initiatives such as:

  • reducing the use of high global warming potential refrigerants and swapping to lower ones.
  • initiatives to ensure refrigerants used are not leaked to the atmosphere where they will cause damage. 
  • ensuring the buildings are well insulated to reduce the need for mechanical refrigeration.
  • reusing waste heat as part of district heating or cooling systems.

Without mechanical refrigeration people had to use ice imported from Norway or stored in ice houses underground to keep things cool. But it didn't last all year.


Some of the first chemical refrigerants used were carbon dioxide and ammonia when vapour compression refrigeration was invented to meet growing demand and improve storage of fresh food. But these refrigerants are either toxic, flammable or work at high pressure that can be dangerous.


To improve safety, scientists developed chemical refrigerants that became widely used as the demand for cooling increased. CFC (Chlorofluorcarbons) were developed in the USA in the 1930s. But in the mid-1980s, scientists discovered that CFCs were damaging the ozone layer in the Earth's upper atmosphere. They were replaced by HCFCs (hydrofluorocarbons) which had less potential to damage the ozone layer.


The Montreal Protocol in 1987 led to a global phase out of all ozone depleting chemicals in refrigeration. So scientists developed HFCs (hydrofluorocarbons) that have zero ozone depleting properties.


Subsequently it was found that HFCs are global warming agents and their use is now regulated under the Kyoto Protocol of 1992, although some types of HFC called HFO have been developed that have a much lower impact.


Many users of refrigeration and air conditioning are now turning back to Carbon Dioxide and Ammonia (and Hydrocabons) as they have zero ozone depleting potential and extremely low global warming potential. Engineers are trying to find ways to ensure these refrigerants can be used more safely.


The Future? Lots of new technologies are being explored as alternatives such as Solar Cooling, Liquid Air, Magnetic Refrigeration. Researchers are working in Universities and research labs across the globe to find better, safer refrigerants.

Cooling Science Homepage

Careers in refrigeration