The refrigerant used in any particular chiller application must be the subject of careful consideration because there is no silver bullet. The decision on which direction to take will depend on a range of criteria and the relative weighting given to each by those making the assessment. One size does not fit all, says David Blackhurst

Wednesday, 7 November 2012 may well go down in history as a day when many people who design, install, operate or own refrigeration and air conditioning (RAC) plant were forced to 'wake up and smell the coffee'.

On that day, the European Commission (EC) published a news release stating that the proposed update to the existing F-Gas Regulations (European Regulation 842/20006, On Certain Fluorinated Greenhouse Gases) was aiming to ensure a reduction in F-Gas emissions by 80 per cent of today's levels by 2030.

The proposed update is a reflection of the findings of an interim statement published by the EC in late 2011 which, in essence, stated that the jury was still out with regard to the true impact of the F-Gas Regulations, but that it appeared that stabilisation of emissions was an achievable goal. However, the statement also made the point that merely stabilising emissions at today's levels was not compatible with the EC emissions reduction targets.

Policy options considered

Consequently, alongside strengthening the existing legislation to maximise its impact, the EC was also considering other policy options including:

New voluntary agreements.

The introduction of a scheme for phasing down the use F-Gases.

A ban on new equipment containing F-Gases.

Extending the scope of existing provisions to other systems / equipment.

Establishing minimum leakage rates for installations.

The 7 November 2012 news release clarified which of the various policy options under consideration were being proposed for actual implementation. The key proposal is for the introduction of a phase-down measure that from 2015 will limit the total amount of hydrofluorocarbons (HFCs) that can be sold in the EU and reduces this in steps to one fifth of today's sales by 2030. The measure is intended to build on the successful phasing out of ozone-depleting substances which was achieved in the EU 10 years ahead of the schedule agreed internationally under the Montreal Protocol.

The phase-down is to be measured not in tonnes of any particular HFC sold but rather in tonnes equivalent of CO2. In addition the proposals call for servicing bans on those HFCs deemed as having particularly high direct global warming potential (GWP), with the intent of a complete servicing ban for those with GWPs >2,500 by 2020. Included in this criterion are widely used refrigerants such as R404A and R507. Assuming that the proposals are implemented it effectively leaves dead in the water new installations proposing the use of these high direct GWP refrigerants.

While the details of exactly how the update to the regulations will be implemented have still to be finalised and submitted to the European Parliament and the Council for discussion and adoption, it does leave the RAC industry with an immediate on-going quandary of which direction to head in next.

The immediate general impact of the proposals outlined in the EC news release is on-going uncertainty for those using HFC refrigerants. There is little doubt that in the right context the on-going use of HFCs, at least in the short to medium term, is wholly appropriate given the range of applications and consequent locations that refrigeration systems are found in. In general terms the right context should be systems where the design and operational criteria of refrigerant charge minimisation and / or guaranteed leakage prevention are applied.

These criteria are not pie in the sky hopes of the deluded few, but have been proven to be possible given the application of good design and build standards and, very importantly, good service technician training and the consistent application of operational procedures around leak detection and repair.

However, this will only take the RAC industry so far and there is little doubt that the on-going longer term use of HFCs will, at best, be under increasing pressure. This assertion is supported by pointing to the general direction being taken across almost all industry sectors that use refrigeration. That is either not to use HFCs at all in new systems, or to limit their use in line with the criteria of low charge and / or guaranteed leakage prevention.

The alternative direction is, of course, the growing application of the most commonly used natural refrigerants: ammonia (R717), carbon dioxide (R744) and hydrocarbons, such as propane (R290) and propylene (R1270). These are generally seen as the most suitable long-term replacement for both ozone depleting and greenhouse gas refrigerants given their proven reliability and efficiency in terms of performance, reduced energy consumption and low carbon footprint.

The use of natural refrigerants

Where a few years ago the use of these natural refrigerants was seen as the preserve of a limited number of niche applications, generally in the industrial refrigeration market, there are many good case studies of their use in areas that would have been considered inappropriate if not unthinkable less than a generation ago. These include: building services, supermarkets, heat pump applications, ice rinks, etc. These natural refrigerants of course have their challenges, generally related to potential flammability, toxicity or high pressure in operation.

But in terms of the case studies available, creative solutions; such as combined HFC and carbon dioxide systems; good engineering practice along with high installation and operating standards allow the risks to be minimised. The safety record of the range of natural refrigerant applications is very good.

// The author is a director of Star Technical Solutions //