Ben Adamson

New explosive gas atmospheres standard on the way

Field is getting ready for a new version of AS/NZS 60079.10.1:2009, Classification of places – Explosive gasoline atmospheres, because of to look afterwards this yr.

AS/NZS 60079.10.1:2009 is a modified version of the IEC 60079-10-1 regular, released in 2008. Given that then there have been two updates to the IEC common, in 2015 and 2020. The Specifications Australia committee has thought of the IEC 2020 model, and it is anticipated to be printed, with modifications, as an Australian regular in late 2022.

Ben Adamson, F.AIRAH, who serves on committees with Benchmarks Australia and the Worldwide Electrotechnical Commission, states that the new variation of the regular will be of distinct curiosity in Australia’s transforming HVAC&R landscape.

“In the past, this conventional has experienced small relevance to Australian HVAC practitioners, as flammable refrigerants have seldom been made use of in HVAC,” suggests Adamson. “The R fraternity have some desire in 60079.10.1 because of to the use of ammonia, which is minimal flammability (class B2L) but the Australian annexes in AS/NZS 60079.10.1:2009 incorporate precise provisions relating to ammonia, and the ammonia earth is familiar with these. Other flammables, these kinds of as propane, have been made use of generally in large units for the oil, fuel and petrochemical industries, wherever the use of flammables is common and has been practiced properly for a lot of many years.”

But, as Adamson factors out, flammable (A2L) HFOs and a flammable HFCs these types of as R32 are significantly getting used.

“Small systems with restricted costs of A2Ls (commonly <1kg) are covered under specific appliance standards,” he says, “but we are now seeing package chillers containing 100kg or more of R1234ze, R1234yf or R32, all A2Ls.”

Adamson notes that the A2L classification is not ecognized in Australia under flammable gas standards, and clause, in AS/NZS 5149.3:2016 states:

Machinery rooms with group A2L, A2, B2L, B2, A3 and B3 refrigerants, where it is possible for the concentration to exceed the practical limit or RCL (20 % of LFL), or for a flammable atmosphere to exist at any location, shall be assessed for hazardous areas in accordance with AS/NZS 60079.10.1.

“Any installation of a large package chiller for an HVAC application must conduct an appropriate design review and risk assessment in accordance with AS/NZS 60079.10.1,” says Adamson. “This will be a new experience for most HVAC practitioners in Australia.”

Adamson says there are a number of things practitioners can do to prepare.

“If considering an A2L installation, the designer and installer should read the current AS/NZS60079.10.1:2009, AS/NZS 5149.3:2016 and the latest IEC 60079.10.1(2020) and watch this space for more news later this year,” he says.

“If someone has already installed an A2L chiller without considering the flammability implications, that installation may be illegal or dangerous, or both. That carries major implications for insurance and liability, and should be reviewed as a matter of urgency.

“Finally, ensure that the person undertaking and signing off risk assessments is competent in the area of flammable gas atmospheres.”

Adamson recently presented on this topic at Refrigeration 2022, and is due to provide an update at the Future of HVAC 2022.

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