Calls for ban on hydrocarbon retrofits

AUSTRALIA: A leading industry body has called for action to stop the use of hydrocarbons in vehicle air conditioning systems after two people are said to have been seriously injured in an explosion in Perth recently.

VASA, the body representing vehicle air conditioning specialists in Australasia, has warned that many more could be hurt or killed by similar incidents if people are allowed to keep filling vehicle air conditioning systems with highly flammable non-standard refrigerants.

According to VASA, the explosion involved an older commercial vehicle that had been filled with a hydrocarbon refrigerant, rather than R134a for which it was designed. Worksafe, a division of the Australian government’s Department of Commerce is said to be investigating the incident. Although full details are not yet known, VASA says it understands that excessive pressure in the system caused the thermostatic expansion valve to fail.

Both victims are said to have been occupants of the vehicle when hydrocarbon refrigerant was suddenly released into the cabin and ignited.

VASA is in communication with those carrying out the ongoing investigations and believes that something must be done to prevent people using flammable hydrocarbon refrigerants in systems designed for R134a.

Minor burns

And it’s by no means the first such incident. Last year Australia’s Mining & Quarrying Occupational Health & Safety Committee reported on an incident where a truck driver received minor burns caused by the ignition of a hydrocarbon blend in his vehicle’s air conditioning system.

It was found that the original R134a refrigerant in the air conditioning system had been replaced with M30 hydrocarbon gas, a blend of propane and isobutane. Freely available in the Far East and Australasia, M30 is variously advertised as a direct replacement for R12 and R134a and described as “efficient and safe” and “requiring no modification to existing air conditioning or refrigeration systems”.

The Mining & Quarrying Occupational Health & Safety Committee report blamed that incident on a lack of awareness of the increased risk of fire when hydrocarbon gases are substituted in air conditioning systems. Mechanically, it found loose connections allowing gas to leak from the system into the housing where it was likely to have been ignited by the ac fan when the vehicle was turned on.

Government review

News of the most recent incident in Perth follows the announcement that the Australian government is to review its greenhouse gas laws amid concerns that the country’s controversial carbon tax, which has pushed up HFC refrigerant prices, has led to the unsafe handling and use of alternative gases in systems that were not designed for their use.

VASA says a loophole in the law allows unlicensed operators to access flammable refrigerants and set up shop without proper training or safety knowledge. It also points out that no vehicle sold on the Australian market has been designed or approved to use hydrocarbon refrigerants and, further, that use of these refrigerants have been known to damage air conditioning systems.

Russian roulette

“It is alarming to find, in most instances, the vehicle owner has not even been informed, before the highly flammable non-standard gas has been charged into their vehicle air conditioning system,” said VASA president Ian Stangroome. “The dodgy cowboys are playing Russian roulette with other peoples’ safety and their wallets.”

There are concerns that, faced with the high costs of HFCs, some vehicle engineers may be using hydrocarbons in systems that were never designed for it and leaving dangers for  engineers in the future who are unaware that the vehicles ac system contains hydrocarbons.

In a white paper produced by the association in 2012, it said that its members had reported that due to the lower charge levels of hydrocarbons, the low side pressure control in cycling clutch orifice tube systems often has to be by-passed to allow the compressor to run long enough for the system to chill and that the low charge level may also not allow for efficient lubricating oil return to the compressor.

Members were also said to have reported that in many instances where R134a had been replaced with hydrocarbon refrigerant, the system performance was unsatisfactory or failed to cool at all.

“It’s not what the users of hydrocarbons know about air conditioning that VASA worries about, it’s what they don’t know that is dangerous and costly for motorists, the industry and its reputation,” the association maintains.

Sensitive to accusations of being a front for the refrigerant manufacturers when VASA has voiced similar concerns in the past, a VASA spokesperson said: “VASA does not determine which refrigerant gas should be used. The manufacturersʼ design, engineers “do”. As a professional organisation, VASA can only recommend manufacturersʼ specifications. To put it another way – if a hydrocarbon system is ever designed for use in automotive, VASA would be the first to conduct training sessions on this technology.”

Ian Maclaine-Cross

Australians have a history of dabbling with hydrocarbons. The most infamous incident was that involving university lecturer Dr Ian Maclaine-Cross who, in attempting to prove the safety of hydrocarbons as refrigerants in car air conditioning systems caused an explosion and fire which left him with first degree burns and injured four bystanders.

While seated in his own vehicle, with all doors and windows shut, MacLaine-Cross discharged two aerosol containers containing around 343g of propane and isobutane. He then lit a match, causing an explosion and burst of flame, bending the four passenger doors outwards, melting part of the car’s interior roof lining and smashing one of the windows.

He later pleaded guilty to negligently and carelessly using a hydrocarbon gas in such a manner and circumstance as to cause or to be likely to cause injury to himself. He was bound over for good behaviour for 12 months and was ordered to pay costs totalling AUS$5,720. (A video of the test can still be found on youtube)