International Refrigerant Standards and their Influence on the Global HVAC Industry and Refrigerant Replacement

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1 International Refrigerant Standards and their Influence on the Global HVAC Industry and Refrigerant Replacement Tom Watson, P.E. Fellow ASHRAE, Life Member President ASHRAE

2 Issues Choosing a refrigerant requires more knowledge Environmental concerns due to: ODP (ozone depleting potential) GWP (global warming potential) energy efficiency LCCP (life cycle climate performance Safety standards being updated to reflect increasing interest in flammable/mildly flammable working fluids

3 Standards Flammability/toxicity requirements covered by ASHRAE safety standards 15 and 34 and their international equivalents (ISO 5149, ISO 817) Other organizations adopt ASHRAE technical requirements into codes and regulations Major ASHRAE standards dealing with refrigerants are: Standard 34, Designation and Safety Classification of Refrigerants Standard 15, Safety Standard for Refrigeration Systems Standard 147, Reducing the Release of Halogenated Refrigerants from Refrigerating and Air-Conditioning Equipment. ASHRAE Position Document on Refrigerants and their Responsible Use

4 ASHRAE Standard 34

5 2L Flammability Classification

6 Standard 34 Toxicity Classification Based on chronic (long term) measure Class A has PEL > 400 PPM Class B has PEL < 400 PPM PEL = Permissible Exposure Limit Flammability Classification Based on ASTM E 681 with electrically activated match Class 1 - no flame propagation Class 2 - LFL > 0.10 kg/m^3 and hc < 19 MJ/kg Class 2L Cl 2 w/ burning velocity < 10 cm / sec Class 3 - LFL < 0.10 kg/m^3 or hc > 19 MJ/kg

7 Standard 34 Activity ASHRAE 34 defined Class 2L Years of work to differentiate Class 2L from Class 2/3 Single criteria: Flame speed < 10 cm/s Refrigerants that fall into new category include: A2L R-32 R-143a R-1234yf R-1234ze B2L Ammonia Change in flammability rating does not alter toxicity rating Approved by Standards Committee in Feb 2010

8 ISO 817:2005, Refrigerants Designation System ISO 817:2005 is second edition of ISO 817 First edition published in 1974 Direct adoption of nomenclature system and refrigerant designations included in Standard Does not include safety classifications

9 ISO/FDIS 817:2012, Refrigerants Designation and Safety Classification System Proposed third edition of ISO 817 includes safety classification system in Standard 34 Standard under development by ISO/TC 86/SC 8 ASHRAE is secretariat of committee Following countries are participating members (Countries in red participated on working group developed third edition of ISO/817 ): Belgium Bulgaria Denmark Egypt France Germany Italy Japan Republic of Korea Netherlands Poland Romania Russian Federation United Kingdom United States

10 ISO/FDIS 817:2005, Refrigerants Designation and Safety Classification System Final approval ballot, ISO/FDIS 817:2012, failed with 9 positive and 6 negative votes 119 comments received SC 8 to meet April to address comments and prepare for second approval ballot Primary concerns expressed by members voting against 1000 ppm default value for NOEL for cardiac sensitization 2L flammability classification lack of requirements addressing toxicity of combustion products.

11 ISO/FDIS 817:2005, Refrigerants Designation and Safety Classification System ISO 817 contains few variances from Standard 34 More conservative refrigerant concentration limit (using flammable concentration limit) for certain refrigerants, set at 20% of the LFL vs. 25% of LFL in Standard 34 Set CNS effect (anesthetic limit) as 100% of NOEL (no observed effect level). Standard 34 sets limit as 80% of NOEL

12 ASHRAE Standard 15

13 Standard 15 First developed as Safety Code for Mechanical Refrigeration in 1930 Scope design, construction, installation, operation and inspection of mechanical and absorption machines modifications if not identical in function and capacity refrigerant substitutions with different designation Generally written as self-sufficient document, it normatively references other standards, including Standard 34

14 Status Standard 15 Committee formed ad hoc committee to draft requirements for use of all 2L refrigerants based on data and additional information made available to committee Prior to formal public review of proposed changes, committee sought input through Advisory Public Review Review of Addendum a to Standard initiated in July 2011 Committee has reviewed comments and continues to work on inclusion of requirements for 2L refrigerants

15 Class 2L Refrigerants Background Rules for Class 2L must be changed when compared to Class 2 and 3 to be useful. Failing this, there is no point in having Class 2L General guidance for Ad Hoc Working Group Understand safety considerations in real applications considering most flammable refrigerants in new class Rules given in ISO 5149 for use of Class 2L should be considered Standard 15 and IIAR 2 have rules for ammonia - rules should not be altered

16 Correlations with Burning Velocity HFO-1234yf (5,000-10,000) NH3 ( ) R-32 (30-100) R-600a (45) R-152a (Class 2) R-290 (39) E-170 (54) R-1150 (80) Class 2L 1. Similar graphs for other properties (example : HOC) 2. Burning Velocity not a perfect measure but provides reasonable discrimination of refrigerants Class 2L refrigerants are flammable and can be ignited

17 Standard 15 Concept Avoid ignition event entirely Eliminate sources of ignition from areas where 2L refrigerant migrates during leak event Provide air movement to mitigate ignition Risk of ignition directly proportional to time that large refrigerant leak fills a space at concentration above LFL. Use Ventilation to dilute and exhaust refrigerant Standard 15 Committee needed technical justification for proposed standards change through CFD and/or testing.

18 Concepts Used for ASHRAE 15 If RCL is exceeded, then equipment is located in MER MER Emergency Ventilation is 30 ACH Lower edge of mechanical ventilation opening shall be as low as practical (heavier than air refrigerant) Ceiling ventilation (lighter than air refrigerant = ammonia) Any permanent source of electrical ignition shall be located > 0.5 m. above the ground, but not in spill zone for any wall mounted unit. No open flames and hot surfaces (< 700 C) Equipment located outdoors and low probability system have no special requirements

19 ISO/FDIS 5149 Refrigerating Systems and Heat Pumps Safety and Environmental Requirements Consists of four parts Part 1 Definitions, classification and selection criteria Part 2 Design, construction, testing, marking and documentation Part 3 Installation site Part 4 Operation, maintenance, repair and recovery

20 ISO/FDIS 5149 Refrigerating Systems and Heat Pumps Safety and Environmental Requirements Part 1 includes table of refrigerate charge limitations, taking into consideration refrigerant flammability classification Proposed class 2L limitations consider reduced combustion risk as compared with class 2 and 3 refrigerants Standard would permit higher refrigerant quantities of class 2L refrigerant than for class 2 or 3

21 ISO/FDIS 5149 Refrigerating Systems and Heat Pumps Safety and Environmental Requirements ASHRAE is secretariat of committee Following countries are participating members (Countries in red represented on working group that developed ISO/FDIS 5149): Australia Belgium Bulgaria Canada Denmark Egypt Finland France Germany India Italy Japan Republic of Korea Netherlands Poland Russian Federation United Kingdom United States

22 ISO/FDIS 5149 Refrigerating Systems and Heat Pumps Safety and Environmental Requirements Efforts began in 1997 to revise ISO 5149:1993, Mechanical refrigerating systems used for cooling and heating Safety requirements, to include environmental safety aspects and refrigeration safety Based on EN 378 Currently under development by ISO/TC 86/SC 1

23 ISO/FDIS 5149 Status ISP/ failed with 7 positive and 8 negative votes (Parts 2 and 3 also failed; Part 4 passed). Total of 384 comments received on all parts Primary concerns expressed by members voting against include: Drafting error in table for flammability class 3 2L refrigerant quantity limit requirements still being developed in IEC, ASHRAE, UL JTG and AHRI working groups. Need for harmonization before publication Treatment of class 3 refrigerant limits (alignment with EN 378, use of either cap limits or absolute kg values) SC 1 met in January 2013 to resolve comments and prepare for second approval ballot, expected to begin this summer

24 Global Warming GWP Power Generation 24

25 Summary ASHRAE and ISO Standards Including Low GWP Refrigerants A2L Low burning velocity Natural Refrigerants Energy Efficiency is a Key CO 2 Reduction Due to Power generation for HVAC&R

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