Open-access content Monday 3rd November 2008
The phasing out of HCFCs and the F-gas regulations dealing with leakage effectively mean that now is an ideal time to review your air-conditioning plant to ensure it is compliant
by Bernard Crouch
6 November 2008
During the 1970s it was discovered that the ozone layer, which protects life on earth from ultraviolet radiation - was being damaged by chlorine atoms released into the stratosphere by the decomposition of CFCs and HCFCs.
In 1987 the Montreal Accord was signed by 24 nations that agreed to phase out of CFCs and HCFCs due to the damage that they were causing to the ozone layer.
The 1997 Kyoto agreement called for a reduction and elimination of the gases such as HFCs. Kyoto also established a relative scale, global warming potential (GWP) as the measure of how much a particular greenhouse gas is estimated to contribute to global warming. Carbon dioxide, the principle greenhouse gas has a GWP of 1. Commonly, CFCs and HCFCs have a GWP in the range of 1000-8000 and are classified and controlled according to their GWP. Another scale, ODP, measures ozone-depletion potential of the gas.
Chlorofluorocarbons (CFCs) are compounds of chlorine, fluorine, and carbon. Decomposition of CFCs in the stratosphere releases chlorine atoms which deplete the ozone layer. CFCs were used as refrigerants, solvents, and aerosol propellants. Common CFCs in air conditioning systems were R-11, R-12. R-11 has the highest ozone depletion potential of any refrigerant and is the reference value 1, ODP is 1 and GWP 4600. R12 has ODP of 1 and GWP of 8100. Both have been completely phased out in the EU.
Hydrochlorofluorocarbons (HCFCs) are compounds of hydrogen, chlorine, fluorine, and carbon and were used as replacements for CFCs. Decomposition of HCFCs in the stratosphere also releases chlorine atoms which deplete stratospheric ozone, but to a much lesser extent than CFCs. HCFCs have ODPs ranging from 0.01 to 0.1. Production of HCFCs is being phased out though the most common HCFC found in air conditioning systems is R-22 (ODP is 0.055, GWP is 1700) R-22 is being phased out and as such is prohibited in new systems. EU production of R-22 will cease in 1 January 2010 though certified recycled R-22 can be used until 1 January 2015. There is no guarantee of supply and the EU is considering regulations to stop hoarding and imports.
There are three main options for replacing R-22: replacing of the system, a "drop-in" replacement refrigerant or take no action. Replacement has a high capital cost, however a new system will have 30-70 per cent better energy efficiency with payback on energy cost alone of 4-7 years. The capital cost will be entitled to an enhanced capital allowance (ECA) against corporation tax. New systems have features designed to make compliance with the F-gas regulations less costly.
A "drop-in" replacement refrigerant should be seen as a stopgap measure pending replacement. Life is not being extended, efficiency will be reduced by 15-30 per cent and maintenance costs will be higher due to the use of a blended HFC which cannot be topped up like single compounds and must be decanted and refilled with new.
Taking no action and using existing plant with recycled HCFCs might be seen as a low cost option, however the efficiency of system is not being improved. It must also be considered that beyond 2010 certified reclaimed HCFCs might not be available at reasonable cost. Action will need to be taken before 2015.
HFCs are compounds of hydrogen, fluorine and carbon used as replacements for CFCs and HCFCs. Because they do not contain chlorine, HFCs do not deplete the ozone layer so have an OPD of zero. But some have high GWPs.The most common HFCs found in air conditioning systems are: R407C and R-134a.
R407C is a blend of HFC compounds and has an ODP of zero and a GWP of 1610.Found in new systems R-134a has an ODP of zero and a GWP of 1300 and is a single HFC compound.
Introduced in July 2007, the F-gas regulations, are designed to reduce global warming caused by leaking HFCs. Responsibility for complying with the F-gas regulations lies with "the actual or legal person exercising actual power over the technical functioning". To comply with the F-gas regulations you must prevent leakage, regularly leak test systems (or sites) containing more than 3kg of HFC refrigerant and maintain records for systems with more than 3kg of HFC refrigerant. You must ensure recovery of HFC refrigerants during maintenance and decommissioning and only use qualified staff for leak testing and maintenance. From 2011 all operatives and companies will have to be certified. You must ensure new equipment is labelled stating type and quantity of refrigerant used. HCFCs such as R-22 are not covered by the F-gas regulations but anyone handling such refrigerants must comply instead with regulations on ozone depleting substances.
Bernard Crouch is business development manager at Tuckers Consultancy
- Virgin R-22 will not be available from 2010
- Recycled R-22 can be used until 2014 - if available
- F-gas regulations aimed at preventing HFC leaks
- Replace entire plant
- Modify existing plant to take an HFC
- Do nothing now; take action by 2014
F-gas regulations cover
- a general obligation to prevent leakage
- regular leak testing of equipment and maintaining records for systems with more than 3 kg of HFC refrigerant
- recovery of HFC refrigerants
- use of adequately qualified staff for leak testing and maintenance activities
- labelling of new equipment