ShareISO 5149 standard revision: negative vote
Draft revised ISO/FDIS 5149 (Parts 1 to 4) standard “Refrigerating systems and heat pumps -- Safety and environmental requirements” which was submitted for voting on October 3, 2012, has been rejected by ISO countries (except Part 4 on operation, maintenance, repair and recovery). Due to the negative vote on Parts 1, 2 and 3, it seems there will be an extra iteration on these parts.
Draft revised ISO/FDIS 5149 (Parts 1 to 4) standard “Refrigerating systems and heat pumps -- Safety and environmental requirements” which was submitted for voting on October 3, 2012, has been rejected by ISO countries (except Part 4 on operation, maintenance, repair and recovery).
This project raised numerous reactions since, based on its draft writing, it might restrict allowed refrigerant charge limits of flammable hydrocarbon refrigerants and ammonia in certain applications and conditions.
Indeed, this revised standard could have a significant impact at international level, since many non-industrialized countries that do not necessarily have national standards will consider it within the context of HCFC replacement. Moreover, European EN378 standard, currently under revision, will probably be based on it.
Allowed charge limits are based in particular on the location of the refrigerating system, the occupancy of the area, and the flammability and toxicity of the refrigerant.
Among the controversial provisions of the draft standard, due – according to some experts – to a mistake in the classification of the systems in Part 1 of the draft – which could explain the rejection of the current draft –, a maximum allowed charge of 1 kg could apply in certain conditions to large air-conditioning chillers and heat pumps using hydrocarbons.
Draft ISO 5149 also introduces a new subclass “2L” (mildly flammable) based on ASHRAE classification. For R32, R1234yf and R1234ze, which are classified “A2L”, in many applications 50% more charge is allowed than for hydrocarbons which are classified A3 (no toxicity and higher flammability) and ammonia which is classified “B2L” due to toxicity.
Due to the negative vote on Parts 1, 2 and 3, it seems there will be an extra iteration on these parts.
This project raised numerous reactions since, based on its draft writing, it might restrict allowed refrigerant charge limits of flammable hydrocarbon refrigerants and ammonia in certain applications and conditions.
Indeed, this revised standard could have a significant impact at international level, since many non-industrialized countries that do not necessarily have national standards will consider it within the context of HCFC replacement. Moreover, European EN378 standard, currently under revision, will probably be based on it.
Allowed charge limits are based in particular on the location of the refrigerating system, the occupancy of the area, and the flammability and toxicity of the refrigerant.
Among the controversial provisions of the draft standard, due – according to some experts – to a mistake in the classification of the systems in Part 1 of the draft – which could explain the rejection of the current draft –, a maximum allowed charge of 1 kg could apply in certain conditions to large air-conditioning chillers and heat pumps using hydrocarbons.
Draft ISO 5149 also introduces a new subclass “2L” (mildly flammable) based on ASHRAE classification. For R32, R1234yf and R1234ze, which are classified “A2L”, in many applications 50% more charge is allowed than for hydrocarbons which are classified A3 (no toxicity and higher flammability) and ammonia which is classified “B2L” due to toxicity.
Due to the negative vote on Parts 1, 2 and 3, it seems there will be an extra iteration on these parts.