A2L Refrigerants. Objectives 14/09/2017

Transcription

1 A2L Refrigerants RMC HRAI Quebec City August 17, 2017 Greg Scrivener Objectives 1) Learn the current state of codes and standards in relation to A2L refrigerants 2) Examine some of the risks associated with flammable refrigerants 3) Examine some of the ongoing research 1

2 Kigali Amendment Refrigerants in North America Today Air Conditioning: A very large amount of installed R22(HCFC) equipment HFC replacement refrigerant available (R438A etc) New equipment R410A (HFC) Some equipment R407C Chillers R123 (HCFC) - No available alternative yet New chillers R134A (HFC) 2

3 Refrigerants in North America Today Refrigeration A large number of refrigerants in use R404A (HFC) and R507A (HFC)make up the largest percentage of commercial refrigerant for new installations R134A (HFC) popular in smaller equipment Many existing systems are using R22 - HFC replacements are available for applications that don t use flooded chillers. CO 2 in limited supermarket and industrial applications Ammonia in large industrial applications Refrigerant Classification Changes Refrigerants are classified by flammability and toxicity by the ASHRAE Standard 34 (ISO 817 in Europe and some other countries) Toxicity Classification A B An occupational exposure limit (OEL) of 400ppm or greater An OEL less than 400ppm 3

4 If a class 2 refrigerant has a burning velocity of 10cm/s or less then it can now be classified as a 2L refrigerant. 2L Classification Burning Velocity 10cm/s or less This additional classification allows different safety standards to be applied to refrigerants with lower flammability. 4

5 The problem? Refrigerant Ozone Depleting Potential Global Warming Potential R ,900 R R R134A R404A R R410A R407C Low-GPW refrigerants What s Low? 5

6 High R507 (3980) A1 R404A (3920) A1 R410A (2088) A1 R407C (1774) A1 R134A (1430) A1 R448A (1272) A1 R32 (675) A2L R450A (547) A1 Ultra Low R1234yf (<4) A2L R290 (3.3) A3 R744 (1) A1 R717 (0) B2L It appears we are going to need to be able to use flammable refrigerants. There are low and ultra-low GWP options and technology available right now Safety Standards and environmental regulation are separate 6

7 Codes and Standards can be written by anybody They don t mean much from a legal standpoint unless they are adopted into legislation They can be adopted by reference (ex. Building and Fire Codes) UL ULC CSA ETL Listing Laboratories ASHRAE 15 CSA B52 ISO 5149 IIAR-2 Safety and Operation Codes and Standards IMC UMC NFPA NBC Other Code or Standard Provincial Legislation Federal Legislation Municipal Bylaws Legislation Regulatory Bodies Safety Inspectors Building Inspectors Environment LEED Corporate Policy Specifying Engineer Other Influences HFC/HFO HC Ammonia CO2 Refrigerant Choice NECCB11 ASHRAE 90.1 ODP and GWP Standards and Agreements Legislation Provincial Legislation Federal Legislation Municipal Bylaws EPA Environment Canada Regulatory Bodies 7

8 What are the Risks? AHRI 8009 Risk Assessment 2015 (other risk assessments have been done) Conclusion: Risks are significantly lower than the risks of common hazard events associated with other causes and also well below risks commonly accepted by the general public. FIRE Fire Event Products of Combustion = Hydrogen Fluoride HF was not considered in the AHRI 8009 Risk Assessment but they implied that it was not likely very relevant. Do we know enough about the risks? AHRI, ASHRAE and the US DOE contributed a combined $5M to ongoing research. Including full scale testing. 8

9 RCL, ATEL, OEL, LFL, UFL. RCL is what determines maximum refrigerant charge in a system. Poorly enforced in almost all cases designers often do not even do calculations This is an ongoing issue for VRF systems. 9

10 Mitigating the Risks Air Movement Charge Limits ASHRAE 15 ASHRAE 34 created the 2L refrigerant category in 2010 ASHRAE 15 No changes to date to allow for less restrictive use of 2L refrigerants. Ammonia and has some significant restrictions on charge quantity in certain occupancies ASHRAE 15 exempts some listed equipment UL has listed and is in the process of listing A3 refrigerants in small applications and A2L in larger applications 10

11 ASHRAE 15 Addendum D 2L refrigerant in human comfort applications Third public review coming soon Will allow only listed A2L equipment for use in human comfort with some restrictions. Allows exceeding the RCL in areas accessible for only service and maintenance. ASHRAE 15.2 Residential The 15.2 subcommittee is developing a residential standard. It will likely be released for an Advisory Public Review this fall. This will be important to the future residential installations. 11

12 ASHRAE 15 Addendum H Machine Rooms Has gone out for one public review. The current sticking points Machine room ventilation (and other ventilation really??) Leak detector parameters and function Existing code that hasn t really mattered that much before. 12

13 In Canada CSA B52 is the safety code for refrigeration B52 allows up to 6.6lb of ANY refrigerant in any occupancy as long as the system is listed AND the installation complies with the listing agency s installation requirements 13

14 Who is doing the enforcement? 14

15 For consideration in Canada What happens when the listing requires compliance with a US installation code How does this get handled in Canada? Canada has for the most part been absent in the code discussions. If everything under 3 tons is exempt, is there an avenue for enforcement? How would enforcement work? Service and Operations How much did risk assessments take service into account? RSES has flammable refrigerant training program. We have been working with flammable refrigerants for a while but not in residential settings. Do we know anything about parts of the world that have been using the refrigerant? 15

16 The environment is driving the changes Different jurisdictions are acting with different urgency and direction A patchwork of codes, standards, legislation and regulation exists allowing some adoption of flammable and slightly flammable refrigerant Technology exists in most cases (but not all) to phase down and limit high GWP HFC refrigerants Questions 16