Natural-borne chillers

Air conditioning manufacturers have turned to hfc (hydrofluorocarbon) refrigerants such as R134a, R407C, R410A and R404A for their latest breeds of equipment. Unfortunately, while these gases have low ozone depleting potential, they have been found to be potent global warming gases. As such, the UK government wants them phased out if it is to meet its commitment to the Kyoto Protocol.

What gases are left? Engineers are increasingly looking to nature which throws up some very effective refrigerants in the shape of propane and ethane, for example. These hydrocarbons (hcs) are derived from liquefied petroleum gas, do not damage the ozone layer and have a negligible global warming effect. They do, however, have the obvious drawback of being flammable and need careful installation.

Calor Gas Refrigeration's CARE range of refrigerants offers solutions for a variety of applications, from domestic fridges through to commercial and industrial markets. CARE 40 (R290 or propane), CARE 45 (R1270 or propene) and CARE 50 (a blend of R290 and R170 or ethane) offer alternatives to R22, R407C and R404A.

You would expect the likes of ethical retailer The Body Shop to be in the front line of testing these products. It is currently running trials with a view to using them in future developments. "We wanted something that was non-ozone depleting and which doesn't contribute to global warming, but was also energy efficient – hydrocarbons seemed the best solution," says The Body Shop's Service Centre environmental manager Janet Shepherd. The company had already applied the refrigerants to its fridges and catering units but is now examining in-store air conditioning.

The Body Shop has found a supplier that can guarantee and support the system in the shape of Earthcare Products. Earthcare supplied and installed a split system from its VEF (Very Environmentally Friendly) range charged with Calor's CARE 40 for trial at the group's Richmond store.

"These systems minimise environmental impact by offering the so-called 'dream ticket combination' of natural refrigerants and optimised efficiency," says Earthcare's Nick Cox. The result is an impressive efficiency gain of 20% over the original HCFC22 systems employed by The Body Shop. "Our approach meant that we could address both the direct and indirect aspects of global warming impact," says Cox. "All of the units have been re-engineered to optimise their performance with CARE refrigerants, while the use of motor voltage controllers brought indirect emissions down by reducing energy consumption."

  It is not just the sandal brigade that are keen to embrace hydrocarbon refrigerants. HM Customs and Excise's offices in Edinburgh benefit from a refurbished cooling system, where two fresh air packaged heat pumps manufactured by Air Handlers Northern were fitted to complement the existing air conditioning. CARE 50 was chosen as the refrigerant.

The use of hydrocarbons in tandem with heat recovery was seen as an ideal combination to deliver an integrated environmentally friendly and energy efficient solution. "The properties of CARE 50 make it ideal for minimising new equipment's impact on the environment," says David Clayton of Air Handlers. "It also works very well with a low energy solution like this one to ensure that the end client has the added benefit of very low running costs."

Consulting engineers ACDP of Maidenhead produced the original design brief to Lorne Stewart's Leigh office, with Foremans of Manchester responsible for the detailed design. Lorne Stewart, the m&e contractor for the refurbishment, also installed the two units.

International food and drink giant Nestlé has become the latest major refrigeration user to reject hfcs in favour of natural refrigerants. The company, which operates 479 factories around the world, will no longer specify any hfc plant for these operations and will announce a similar policy for its non-industrial processes, such as its office air conditioning, "in the not too distant future". Existing plant operating on hcfc and hfc refrigerants will be replaced by the end of this decade ahead of the legislative timetable, a UK spokesman added.

"Like the UK government, we believe that hfcs have no long-term future. Nestlé genuinely believes that and we recognise that we have a role to play from an environmental perspective. But there is also a practical side to this: we don't want to invest in plant and then have to disinvest in a few years time from equipment that still has operating life," the spokesman said.

Other clients, from cider-maker Bulmers to supermarket chain Sainsbury's, are following suit but m&e contractors need specialist knowledge if they are to get involved in hydrocarbon installation. Calor Gas Refrigeration runs training courses on correct handling of its CARE range and installation of associated products. It is not enough simply to hold a City & Guilds 2077 certificate in refrigerant handling.

The client demand is there and can only get greater as controls on hcfcs and hfcs start to bite. The message is clear: if you want to get involved in this growing market, get yourself trained.