The most common form of refrigeration in supermarkets has been the
direct expansion system, whereby a refrigerant, usually CFCs or HCFCs,
circulates throughout the store in a long network of pipes, connected to
refrigeration units.
The most common form of refrigeration in supermarkets has been the
direct expansion system, whereby a refrigerant, usually CFCs or HCFCs,
circulates throughout the store in a long network of pipes, connected to
refrigeration units.
Supermarkets are the biggest sector of the refrigeration industry and
are responsible for the biggest demand for CFCs and HCFCs. A supermarket
refrigeration system can contain up to two tonnes of CFCs or HCFCs.
A 1992 UK government study estimated the following future demands for
HCFCs (in unweighed tonnes) in that country based on the existing use of
CFCs. *
| Year | All industry uses | RAC industry | Supermarkets |
| 1995 | 12,800 | 8,064 | 4516 |
| 2000 | 16,500 | 11,550 | 6468 |
| 2005 | 20,400 | 15,300 | 8568 |
Demand for CFCs and HCFCs is mostly to top up leaking systems. Leaking
gases obviously go straight into the atmosphere and cause damage. Most
refrigeration systems, if not all, that contain CFCs and HCFCs leak. The
total amount of gases in refrigeration equipment is called the bank, and
the average leakage rate for all systems is at the rate of 20 per cent
of the bank every year. Supermarkets leak at double this rate. This is
due to such factors as poor design, installation and maintenance, leaky
pipes and components. Each store may have up to two miles of pipes
containing harmful gases, making it very difficult to get at the source
of the leaks. In practice many systems leak at higher rates than this,
and some stores have catastrophic failures, where the whole charge leaks
in one go.
As a result of the 1996 ban on production of CFCs in industrialized
countries all supermarket chains are now engaged in a process of
change. Many plan to replace CFCs with other damaging products from the
chemical industry -- hydrochlorofluorocarbons (HCFCs) and
hydrofluorocarbons (HFCs). As explained above, these substances are
environmentally unacceptable alternatives to CFCs.
