The importance of refurbishment
Had you realised that an air-conditioning system installed 10 years ago is around 75% less efficient than today’s state-of-the art systems? Likewise, had you realised that many general lighting systems can readily be upgraded to reduce their power consumption by 20% or more by replacing luminaires or improving lighting controls? Those are just two nuggets of information from the feature on refurbishment in this issue. There is much more besides on opportunities to reduce energy consumption in this feature and another on boilers. The importance attached by the current Building Regulations to reducing the carbon footprint of buildings during refurbishment (Parts L1B and L2B) and sustaining the energy efficiency of buildings in the long term puts new emphasis on maintenance and refurbishment. Even if every new building to be built in Britain from this day forth had zero emissions of carbon dioxide, the Government’s targets for reducing carbon-dioxide emissions would never be achieved. It is widely understood that not only must new buildings be built and operated to high and demanding standards but that existing buildings must make their contribution. The best time for existing buildings to be upgraded to reduce their use of energy is when major refurbishment work is carried out and when plant is replaced — which is why the latest Building Regulations have sections devoted to refurbishment. But it is not just carbon-dioxide emissions associated with burning fossil fuels to service buildings that contribute to global warming. There are other greenhouse gases, and those that are closest to home for building-services engineers and people who operate buildings are the refrigerants used in air-conditioning systems. Long gone are the days when refrigerants attacked the ozone layer, leading to their use being banned. R22, which has a small ozone-depletion potential, is still widely used — but not for long. Unfortunately, the new generation of refrigerants, while not posing a threat to the ozone layer, have very high global-warming effects. R125, for example, which is a component of R407C and R410A, has a global-warming potential 3400 times greater than carbon dioxide — hence the F-gas Regulation that comes into effect in July to prevent such substances entering the atmosphere. The logic behind containment is that no alternative substances are available. It is ironic that ozone-depleting refrigerants such as R11, R12 and R13 were banned when a similar policy of containment could have had the desired effect — but that is a lesson of history. There is no single ‘silver-bullet’ solution to reducing carbon-dioxide emissions from existing buildings — making the challenge both interesting and exciting.