A sealed system which operates for its useful life (say 20 years) without ever needing additional refrigerant to be added in order to keep it running within normal operating parameters is considered to be "leak tight". That means that it has not leaked enough refrigerant to effect system performance (typically less than 10% of original charge°. Below this 10% lifetime "benmark" the system leaks are not practically measurable - and it is deemed a "leak tight" system.
Refrigerant containment is a priority for everyone who designs, builds, uses or maintains refrigeration or airconditioning systems. If we want to continue to have the best choice of refrigerants from which to select in the future we must ensure that refrigerant is contained within the system. If the refrigerant is contained within a system its environmental impact is negligible. But if allowed to leak to atmosphere it is a significant contributor to global warming. Refrigeration system which are allowed to continue to leak are also likely to be less energy efficient, resulting in additional indirect CO2 emissions at the electricity generating plant, along with higher running costs.
The worldwide focus on the effects of climate change and the measures being taken to combat it (such as the Montreal and Kyoto Protocols) have highlighted the need to improve the 'total emissions' of refrigeration equipment. Emissions are the total CO2 'discharge' of a plant including the energy used to power it (and the resulting CO2 emitted from the power station) and also the equivalent CO2 emitted in the form of refrigerant fluid escaping into the atmosphere. ODS, GWP, TEWI, LCCP and F-Gas have all become familiar acronyms for the tools, measures and regulations that we now apply to the impact of refrigeration systems on climate change. The purpose of this project is to raise awareness of the nature of refrigerant leaks, what they are, what causes them and what can be done through good design and engineering practices to reduce or eliminate the risk of measurable leaks occurring.
End users of refrigeration or air conditioning (RAC) equipment are responsible for complying with the Fluorinated Gas (F Gas) and Ozone Depleting Substances (ODS) Regulation because they are the "operator" of the system. The aim of these regulations is to reduce leakage of HFC and HCFC type refrigerants. The F Gas regulation also provides a minimum standard for leak testing and training of personnel handling refrigerants. EC Regulation 843/2006 states that the operator shall, using all measures which are technically feasible and do not entail disproportionate cost:
Refrigeration and air conditioning equipment are designed as sealed systems and with appropriate and regular service and maintenance they should remain so. However over the lifetime of a system, which could be around 20 years, leaks can develop because of operational issues such as vibration, environmental conditions, general wear and tear. Good service and maintenance by competent engineers given sufficient time and equipment to make repairs will minimise leakage.
For some equipment owners low first cost and time pressures are a priority and this can increase the risk of leaks being missed or developing in the future. The REAL Zero approach is to provide technical advice for everyone involved in the life of a refrigerating system to maximise opportunities to reduce leakage and save costs in the longer term. If designers, specifiers, owners and service and maintenance personnel focus on reducing leakage, substantial reductions in emissions will be achieveable.
To find out more about these new qualifications you should contact the two awarding bodies in the UK who can advise on current courses available:
The data for leakage rates varies widely, and depends on the source, scope (national, EU or worldwide) and the definitions used. Air-conditioning can be any combination of domestic, commercial to 'industrial' size. Supermarkets are sometimes included in 'commercial', and in some sources not. Some data sources include 'catastrophic total system refrigerant charge losses' and others exclude these to deal with only 'normal' operational refrigerant leaks. Average UK leakage rates were not identified as part of this project as the sample surveyed was not statistically significantly. An example of estimated impact of direct emissions through leakage in the EU is available in the tables below:
|Market Segment||Global Warming Emission|
(Mtonnes CO2 equivalent)
|% of GW impact related to energy use|
|Direct HFC Emissions||Indirect CO2 Emissions||Total Global Warming Impact|
|Annual EU GWG Emission (Mtonnes CO2 equivalent) Direct HFC Emissions
HEAP, R.D. Refrigeration and air conditioning - the response to climate change. IIR Bulletin 2001-5.
|Air-conditioning, DX systems||2.6||10.0||12.6||79%|
|Small Commercial Distributed||1.8||12.0||13.8||87%|
|Other Small Hermetic||0.3||12.0||12.3||98%|
The REAL Zero material relates to stationary refrigeration and air conditioning equipment and heat pumps only. There are distinct and different legal, technical and training requirements for those involved in car air conditioning systems. F Gas Support can provide guidance on these requirements.