ÐÇ¿Õ´«Ã½

In an attempt to limit EU emissions of fluorinated gases (F-gases), the European Commission has proposed a new series of regulations, expected to be endorsed by the European Parliament in mid 2006 and come into force in 2007. F-gases are synthetic compounds, and one of six greenhouse gases that the EU has committed to reduce by 8% below 1990 levels before 2012, as defined by the Kyoto Protocol.

Current F-gases, HFC134a, 407C and 410A, cause 1300 to 1890 times more global warming than a similar mass of CO2. Used in everything from aerosol cans to air conditioning systems, these compounds are becoming increasingly prevalent as they continue to replace the harmful, banned CFCs and HCFCs, which have serious potential to deplete the ozone layer.

As it is only when the gases escape into the atmosphere that they become harmful, one of the key approaches to dealing with F-gases is containment. This involves ensuring that equipment is leak-tight, that installation and servicing personnel are well-trained and that F-gases are carefully handled and fully traced at all stages of the refrigerants' life.

The prime objective of the new F-Gas Regulations will be to prevent leakage and to ensure repairs are undertaken as soon as possible after a leak is detected. It places the onus of responsibility on end-users to adhere to the legislation that will clearly define the frequency and stringency of maintenance servicing for any equipment, including air-conditioning systems, that contains over 3 kg of F-gas within a single unit.

ÐÇ¿Õ´«Ã½ services engineers must, therefore, take the F-Gas Regulations into consideration immediately by designing and specifying cooling that will reduce the impact of the legislation on the end-user. This action will, in addition, safeguard equipment life cycle costs.

Capacity-governed regulations

The Regulations divide refrigerant systems into three capacity-governed groups: equipment containing 3 kg+ of refrigerant will be fully inspected every 12 months; equipment containing 30 kg+ every six months; and equipment containing 300 kg every three months.

There will also be an obligation for a further inspection one month after a leak has been repaired to ensure the repair has been effective. Additionally, for equipment with 300 kg+ of refrigerant, a leak detection system must be installed and tested annually.

Engineers must take the regulations into account immediately by designing cooling to reduce the impact of this legislation on the end user

It is obvious that the Regulations will disadvantage end-users whose air-conditioning systems contain over 3 kg of refrigerant, since equipment with a lower charge will be subject to normal maintenance procedures.

For example, in the case of a standard VRF installation, the average refrigerant charge circulating in pipework around the building is likely to be somewhere between 10 and 50 kg. In the event of a leak, assuming it is noticed at an early stage, the system would need to be closed down and there would be the potential danger of all the refrigerant escaping into the atmosphere. Because of this, the Regulations will require a schedule of mandatory servicing, which is likely to amount to twice a year. This will include not only the main equipment but also the checking of leaks on all the pipework and joints.

This enhanced regime will mean higher maintenance costs and result in increased life cycle costs for the system. An additional consideration is the significant disruption to the end-user and building occupants that such stringent servicing procedures will entail.

To limit the liability of the end user, building services consultants need to be aware of alternative systems that will be less affected by the F-Gas Regulations. One example of this is WRF (Water and Refrigerant Flow), a system that incorporates a water-based heat pump system where only water is circulated through the building and the individual heat pumps contain less than 3 kg of refrigerant.

The heat pumps are inspected as part of a normal (fancoil-type) maintenance routine without any need for pipework inspections. Should a leak occur, only one heat pump would need to be changed and a maximum of between 0.5 and 2.5 kg refrigerant would be discharged.

The CIBSE policy on global warming encourages building services engineers to consider environmental issues at all stages of the life cycle of buildings, including the use of equipment and systems with reduced or zero global warming potential. With the additional impetus of the F-Gas Regulations, it is essential that engineers now develop a clear understanding of how different air-conditioning systems can impact on climate change, emissions of refrigerant and life cycle costs. n