Flammable Refrigerants the Evolving Impact on Codes
Flammable Refrigerants The Evolving Impact on Codes
With appreciation to Danfoss North America and Tidwell Consulting
Today’s Goal
Explore the changing refrirgerant environment and its potential affect on codes.
Courtesy: Johnson Controls (www.johnson controls.com)
2016 ICC Annual Conference Education Programs Kansas City, MO 1 Learning Objectives
• Identify the environmental and code issues associated with the refrigerant gas changes. • Describe simple refrigeration physics, terminology and chemistry. • Identify current public safety code requirements and issues. • Identify proposed changes in refrigeration gases.
Challenge
. Traditional refrigerants are being banned or phased down . Potent greenhouse gases . Both air conditioning and refrigeration . Alternatives are available, but many are flammable . Codes currently do not allow their use
2016 ICC Annual Conference Education Programs Kansas City, MO 2 Part I: Refrigeration Concerns
Why Change?
GLOBAL WARMING POTENTIAL Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFC) INFLUENCE
WARMING
GLOBAL
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
2016 ICC Annual Conference Education Programs Kansas City, MO 3 Montreal Protocol
Phase-out Begins INFLUENCE
January 1, 1989 WARMING GLOBAL WARMING POTENTIAL Chlorofluorocarbons (CFCs) and GLOBAL Hydrochlorofluorocarbons (HCFC)
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
Hydrofluorcarbons
GLOBAL WARMING POTENTIAL Hydrofluorocarbons (HFCs)
Phase-out Begins INFLUENCE
January 1, 1989 WARMING
GLOBAL
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
2016 ICC Annual Conference Education Programs Kansas City, MO 4 Global Demand
Developing Countries Refrigeration High estimate and
A/C
for
Demand
World
Low estimate
Developing Developed Countries
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 Source: National Oceanic and Atmospheric Administration (NOAA)
EU: Move down to low-GWP refrigerants
100% INFLUENCE
WARMING
GLOBAL 20%
1960 1970 1980 1990 2000 2010 2020 2030 2040 2050
2016 ICC Annual Conference Education Programs Kansas City, MO 5 US: GWP Proposed Phaseout (EPA)
Supermarkets Remote Condensing Units
Small vending machines Large vending machines Standalone low temperature devices
Central air conditioners ?
2017 2018 2019 2020
Potential ICC Effects
• IBC 1006.2.2.2 – Egress from refrigeration machinery rooms • IMC Chapter 11 – Mechanical Refrigeration • IFC 606 – Mechanical Refrigeration • Equipment testing • Emergency controls • Treatment and flaring systems
2016 ICC Annual Conference Education Programs Kansas City, MO 6 Part II: Refrigeration Physics
Refrigeration Physics
. Newton’s First Law of Thermodynamics . Conservation of energy: Energy cannot be created or destroyed in chemical reaction U=Q‐W Where: U = change in internal energy Q = heat added to the system (energy in) W = Work done by the system (energy out)
2016 ICC Annual Conference Education Programs Kansas City, MO 7 Heat Properties
. Always moves from warmer to cooler surface . Moves by radiation, convection or conduction . When a refrigerant boils it absorbs heat . When a refrigerant condenses, it releases heat . Heat by a fluid (refrigerant) ‐‐ as it changes from a liquid to a gas ‐‐ lowers the temperature of the objects around it.
Mechanical Refrigeration Cycle
. Compressor pressurizes refrigerant gas
Condenser, where it Draws heat from the rejects heat to refrigerated space outdoors and liquefies
Moves through valves where it expands into a gas
2016 ICC Annual Conference Education Programs Kansas City, MO 8 Mechanical Refrigeration: Operating Scheme (Simplified)
Refrigerated space Usually outdoors
Fan
Mechanical Refrigeration: Definitions
• Compressor – Mechanical equipment that raises refrigerant pressure
Courtesy: Danfoss.com • Condensing Unit -- Assembly of a compressor, condenser, fan motor, controls and a mounting plate
Courtesy: Copeland Refrigeration Units
2016 ICC Annual Conference Education Programs Kansas City, MO 9 Mechanical Refrigeration: Definitions
• Expansion valve -- Adjusts refrigerant flow and pressure to satisfy all load conditions.
• Refrigerant -- Liquid or gaseous cooling medium
Courtesy: Danfoss
Mechanical Refrigeration: Definitions
•CFC – Chlorofluorocarbon
•HFC -- Hydrofluorocarbon
• HCFC -- Hydrochlorofluorocarbon
2016 ICC Annual Conference Education Programs Kansas City, MO 10 Mechanical Refrigeration: Definitions
• Specific heat • Amount of heat per unit mass required to raise the temperature by one (1) degree Celsius (1.8F). • Used to calculate capacity requirements for refrigerating known quantities of product
• Latent heat • Amount of heat absorbed or released by a substance undergoing a change of state (such as ice changing to water or water to steam) at constant temperature and pressure • Occurs in evaporator and drives the cooling process
Mechanical Refrigeration: Definitions
• Azeotrope • Blend of two or more refrigerants with similar boiling points that act as a single fluid. • May exhibit unique and unexpected properties • Zeotrope • Mixture of two or more refrigerants with different boiling points. • Never mixes chemically, predictable properties • Evaporates/condenses of temperature range called “glide”
2016 ICC Annual Conference Education Programs Kansas City, MO 11 Mechanical Refrigeration: Units
• Refrigerant ton – A measure of cooling capacity; not refrigerant.
• The energy removal rate that will freeze one short ton of water at 0 °C (32 °F) in one day. • Historically defined was approximately 11,958 Btu/hr (3.505 kW), and has now been conventionally redefined as exactly 12,000 Btu/hr (3.517 kW) • One ton of refrigeration is equal to 3024 kilo-calories per hour. – Equals 12,000 BTU/ hr divided by 2.204 (pounds per kilogram) divided by 1.8 (°C to °F).
Courtesy: Livescience.com
Mechanical Refrigeration: Units
• Most residential A/C units capacity range:
Tons kW Btu/hr 1 to 53.5‐ 17.5 12,000‐60,000
Courtesy: AC2015.com • Large industrial chiller systems up to:
Tons kW Btu/hr Up to 800 2,800 9,600,000
Courtesy: excaliburlpa.co.uk
2016 ICC Annual Conference Education Programs Kansas City, MO 12 Mechanical Refrigeration: Units
• For code purposes, refrigerants are measured in pounds – Unit of liquid weight – Refrigerants typically have density >1 • Heavier than water • Densities lessen at higher temperatures – Based on internal volume of the refrigeration system • Volume x liquid density at specific temperature = pounds in system – Check the system label.
Mechanical Refrigeration: Side Note
• For response purposes, refrigerants’ vapor density should be considered • Most refrigerant leaks occur as vapor – Vapor density >1 = vapor sinks – Vapor density < 1 = vapor rises
Courtesy: US Chemical Safety Board
2016 ICC Annual Conference Education Programs Kansas City, MO 13 Mechanical Refrigeration: Pounds
Recharging Vessels
Courtesy: Summit Refrigerants
2016 ICC Annual Conference Education Programs Kansas City, MO 14 Part III: Refrigerant Chemistry
Optimal Refrigerant
• Should have low boiling point and low freezing point. • Must have low specific heat and high latent heat. – high specific heat decreases the refrigerating effect per pound of refrigerant, and, – high latent heat at low temperature increases the refrigerating effect per pound of refrigerant.
2016 ICC Annual Conference Education Programs Kansas City, MO 15 Refrigerant Composition
Prefix Represents Examples
R Refrigerant R22, R134a, R717 May include: RC317 C Chlorine Chloroheptafluorocyclobutane R22B1 B Bromine Bromodifluoromethane RFE‐36 F Fluorine Hexafluoropropane R134a H Hydrogen 1,1,2,2‐Tetrafluoroethane RC318 C Carbon Octafluorocyclobutane RE170 E Ether Dimethylether
Refrigerant Nomenclature
Numbering Chemistry Examples Series 000, 100, 200 Hydrocarbon‐based HCFC‐22, HFC 134a, R290 (propane) 400 Zeotropes R‐404A 500 Azeotropes R‐507A 600 Organic R‐600a (isobutane) 1000 Unsaturated organics HFO‐1234yf*
*Will replace HFC‐134a in automobile air conditioning
2016 ICC Annual Conference Education Programs Kansas City, MO 16 Refrigerant Nomenclature
• Legacy refrigerant numbering scheme (R-XXXX) describes chemical composition
R(efrigerant) >Number of double carbon bonds > Carbon atoms > Hydrogen atoms > Fluorine atoms
Hydrocarbons/Derivatives
* R134a : Tetrafluoroethane – CH2FCF3 Carbon Hydrogen Fluorine Nof double carbon bonds R Atoms Atoms Atoms (Placeholder omitted when zero) (Minus 1) (Plus 1) (N/molecule) R 0134
Remaining bonds not accounted for are chlorine.
*a = Isomer stability.
R22: Chlorofluoromethane – CHClF2 Carbon Hydrogen Fluorine Nof double carbon bonds R Atoms Atoms Atoms (Placeholder omitted when zero) (Minus 1) (Plus 1) (N/molecule) R ????
Zero double bonds 1‐1= 0 1+1 = 22 (omitted) (omitted)
2016 ICC Annual Conference Education Programs Kansas City, MO 17 Zeotropic . Zeotropic . Respective refrigerant number and mass proportions . Number designates components, but not amount (molecules) of each . Identifying number in 400 series, assigned arbitrarily (in order of approval) . R407A . (R32/R125/R134a): (20/40/40) . R407B . (R32/R125/R134a): (10/70/20)
R-500 Series . Two-component refrigerant mixtures . a CFC and an HFC, or, . a CFC and an HCFC . Exception: R-507 . a mixture of two HFCs
2016 ICC Annual Conference Education Programs Kansas City, MO 18 Organics/Inorganics
. Organics: given in numerical order in 600 series
. R600a : Isobutane C4H10
. Inorganics: assigned in 700 series by adding molecular mass to 700
. R717: Ammonia NH3
ASHRAE Safety Groups
Flammability Toxicity Group Classification
Group A Group B Lower Toxicity Higher Toxicity
Higher Flammability A3 B3
Lower Flammability A2 B2 Flammability
Low Flammability A2L B2L Increasing
No Flame Propagation A1 B1
Increasing Toxicity
2016 ICC Annual Conference Education Programs Kansas City, MO 19 ASHRAE Safety Groups
Flammability Classification Test At 70F and 14.7 psi Examples Methane Higher LFL <0.10 kg/m3 A3 Propane Latent heat > 4540* Flammability Butane
Lower LFL > 0.10 kg/m3 HCFC-142b A2 Flammability Latent heat < 4540* HFC-152b
Difficult to ignite R-32 A2L Flame speed < 3.94”/sec R1234yf No Flame CFC-11 A1 No flame propagation in air CFC-113 Propagation R-500
* Calories per gram
ASHRAE Safety Groups
Toxicity Groups
Group A Examples Group B Examples
Lower Toxicity Higher Toxicity
No toxicity identified Evidence of toxicity at concentrations ≤ at concentrations 400 ppm <400 ppm
CFC, A1 B1 Seldom used HCFC,
A2 R152a B2 Seldom used
A2L Most Low-GWP HFC B2L Ammonia
A3 Hydrocarbons B3 Hydrocarbons
2016 ICC Annual Conference Education Programs Kansas City, MO 20 Examples
Classification Denomination Formula Safety Classification
Inorganics
R717 Ammonia NH3 B2
R718 Water H2OA1 Hydrocarbons
R170 Ethane CH3CH3 A3
R290 Propane CH3CH2CH3 A3 Halocarbons
R11 Trichlorofluormethane CCl3FA1
Examples (cont’d)
Classification Denomination Formula Safety Classification Hydrochlorofluorocarbons
R22 Chlorodifluoromethane CHClF2 A1 Hydrofluorocarbons
R125 Pentafluorethane CHF2CF3 A1
R32 Difluoromethane CH2F2 A2L Hydrofluorolefins
R1234ze 1,3,3,3‐ C3H2F4 A2L Tetrafluoroproene
R1234yf 2,3,3,3‐ C3H2F4 A2L Tetrafluorpropene
2016 ICC Annual Conference Education Programs Kansas City, MO 21 Vessel Identification
R‐113 R‐13B1 R‐11 Trichlorotrifluoroethane Bromotrifluoromethane Trichlorofluoromethane (CFC) (CFC) (CFC)
Courtesy: RMS of Georgia
R‐22 R‐12 Zeotropic Chlorodifluoromethane Dichlorofluoromethane R‐22/R152a/R‐124 (HCFC) (CFC) (HCFC)
2016 ICC Annual Conference Education Programs Kansas City, MO 22 Part IV: Refrigeration Codes and Standards
The Code Challenge
“State and local fire and building codes are major barriers to the broad deployment and adoption of low‐GWP refrigerants in the U.S.,
“These codes often prohibit the use of flammable or even mildly flammable refrigerants, even in very small amounts less than a typical aerosol spray can.
“Since they’re developed and mandated locally across hundreds or thousands of jurisdictions, codes are difficult to change and create an effective obstacle to manufacturers offering products with low‐ GWP refrigerants that may be flammable or mildly flammable.”
John Galyen, president of Danfoss North America
2016 ICC Annual Conference Education Programs Kansas City, MO 23 Codes and Standards
• ASHRAE 15 – Safety Standard for Refrigeration Systems • ASHRAE 34 – Designation and Classification of Refrigerants
Codes and Standards • IIAR (International Institute of Ammonia Refrigeration) – ANSI/IIAR 2‐2014 American National Standard the Safe Design of Closed‐Circuit Ammonia Refrigeration Systems – ANSI/IIAR Standard 7‐2013 Developing Operating Procedures for Closed‐Circuit Ammonia Mechanical Refrigerating Systems
2016 ICC Annual Conference Education Programs Kansas City, MO 24 Codes and Standards
• UL 207 – Standard for Refrigerant-Containing Components and Accessories, Nonelectrical • UL 412 – Standard for Refrigeration Unit Coolers • UL 471 – Standard for Commercial Refrigerators and Freezers • UL 1995 – Heating and Cooling Equipment
Machinery Rooms
• Construction per IBC • Table 509 – One-hour separation or A/S • §1006.2.2 – > 1,000 ft2 • Two exits or exit access Courtesy: Food Engineering Mag.com • All portions within 150 feet • Doors swing in egress direction – Chapter 28
2016 ICC Annual Conference Education Programs Kansas City, MO 25 International Mechanical Code
• Chapter 11 REFRIGERATION
• Design, installation, construction and repair
• Six-step design protocol
Courtesy: Hussung.com Courtesy: Arescobuyersclub.com
International Mechanical Code
• §1103.2 Occupancy classifications • Institutional • Public assembly • Residential • Commercial • Large mercantile (O.L. > 100) • Industrial • Mixed occupancies
2016 ICC Annual Conference Education Programs Kansas City, MO 26 IMC Design Protocol
1. Refrigeration system’s classification based on likelihood leaks entering occupied area – Low or High probability • Low probability: – Double‐indirect open spray – Indirect closed – Indirect‐vented closed • High probability – Direct – Indirect open spray
System Classifications
Liquid:liquid heat exchangers
Courtesy: resourcecompliance.com
2016 ICC Annual Conference Education Programs Kansas City, MO 27 IMC Design Protocol
2. Refrigerant classification (A1‐B3) 3. Maximum refrigerant quantity per refrigerant, system classification and occupancy 4. System enclosure requirements 5. Refrigeration and application location and installation 6. Non‐factory tested, field erected equipment and appliances
IMC System Application
• § 1104.2 Machinery rooms • Outdoor applications • Institutional applications
• 50% limit on refrigerants Courtesy: Texas Glacier.com • Industrial occupancies and refrigerated rooms • Exceptions for manufacturing, food and beverage prep, meat cutting and storage
2016 ICC Annual Conference Education Programs Kansas City, MO 28 IMC Machinery Rooms
• § 1105 – Design and construction – Ventilation requirements • Normal/emergency • § 1106 – Continuous ventilation for NH Courtesy: sirayooth.com 3 – Remote emergency shutoffs
Refrigerant Piping §1107
• Height above floor • Limited building envelope penetrations • Material limits – Steel, copper, brass, aluminum • Valve identification
Courtesy: Stellar food for Thought.net
2016 ICC Annual Conference Education Programs Kansas City, MO 29 International Fire Code • Section 606 MECHANICAL REFRIGERATION – Processed by PMG Code Action Committee [M] and Fire Code Action Committee – Operational permit required §105.6.40 – IFC regulatory thresholds • Approved FD access at: • 220 pounds of Group A1 • 30 pounds of any other group
• For emergency pressure control systems: • 6.6 pounds flammable, toxic or highly toxic, ammonia
Courtesy: NH3plus.net
International Fire Code
• §606.4 Refrigerant change • Must meet IMC • §606.6 Testing and recordkeeping • Treatment and flaring systems • Equipment in emergency refrigeration control boxes • Fans and equipment for Courtesy: Refrigeration Today.com emergency ventilation • Detection and alarm systems
2016 ICC Annual Conference Education Programs Kansas City, MO 30 International Fire Code
• §606.7 Warning signs • Suitable for refrigerant • Comply with NFPA 704
International Fire Code
• §606.8 Refrigerant detection • In machinery room • Gas concentration area • (Remember vapor density) • Alarm at TLV‐TWA for refrigerant class from IMC
Courtesy: Emerson Climate Technologies
2016 ICC Annual Conference Education Programs Kansas City, MO 31 International Fire Code
• System emergency controls • § 606.9 Remote controls for flammable refrigerant rooms • Break‐glass system emergency shut OFF • Break‐glass ventilation system ON
Courtesy: resourcecompliance.com
International Fire Code
• System controls for flammable, toxic, highly toxic or ammonia • § 606.10 Emergency pressure control system • Automatic crossover valves transfer high pressure gases to low pressure side • Automatic compressor stop
2016 ICC Annual Conference Education Programs Kansas City, MO 32 International Fire Code
• System controls for flammable, toxic, highly toxic or ammonia • § 606.11 Emergency pressure control system • Treatment and flaring systems
Courtesy: bhtank. com Courtesy: Energy‐Concepts. com
Part V: Refrigerant Proposals
2016 ICC Annual Conference Education Programs Kansas City, MO 33 GWP: Traditional Refrigerants
12,000
10,500
9,000 lb CO2
1 7,500 to
6,000 compared
4,500 potential
3,000 warming
1,500 Global
0
Existing CFC Refrigerants
12,000
10,500
9,000 lb CO2
1
to CFCs Use in new equipment obsolete 7,500
compared 6,000
4,500 potential
3,000 warming
Global 1,500
0
2016 ICC Annual Conference Education Programs Kansas City, MO 34 Unacceptable Refrigerants
12,000
10,500 lb CO2
1
9,000 to
CFCs Unacceptable for certain 7,500 EPA applications compared
6,000 potential
4,500 warming
3,000 Global
1,500
0
What Remains
12,000
10,500 lb CO2
1
to
9,000 compared
Not EPA approved for 7,500 CFCs What Remains certain applications potential 6,000 warming 4,500 Global 3,000
1,500
0
2016 ICC Annual Conference Education Programs Kansas City, MO 35 Industry Investment
HVACR industry spent more than $255 million in 2015 to research, develop low-Global Warming Potential and low flammability refrigerants
Courtesy: Johnson Controls. com
2016 Industry Work Plan • Codes & Standards Task Force – Refrigerant producers – Equipment manufacturers – Standards developers Courtesy: PIHO Engineering.com – Consultants – Retailers – Government agencies – Non-governmental organizations
Courtesy: PRSEngineers.com • IFC Fire CAC review
2016 ICC Annual Conference Education Programs Kansas City, MO 36 Where We Are Today
• ASHRAE 15 (Safety Standard for Refrigeration) • Meets twice annually • Subcommittees more frequently • Being re-written • Reorganization in process to make the standard more user friendly • No technical changes
• Flammability experts reviewing scientific literature and looking to plug the knowledge gaps
Where We Are Today
• Draft of A2L-related submitted for Advisory Public Review • Followed by Publication Public Review before changes are finalized
• Pushing to complete the process in time for the 2016 edition of Standard 15
2016 ICC Annual Conference Education Programs Kansas City, MO 37 Where We Are Headed
• “It depends” • Availability of ASHRAE 15 for the next code cycle • Group B IFC proposals now closed • Group A IBC/IMC currently voting • UMD fire test results (ASHRAE grant) • Early detection/ventilation seem to provide promise • ISO approach
• Meanwhile per industry it’s “business as usual” • Safety standard model codes state adoption • Be prepared to accelerate the process • ICC process allows adoption and modification of standards
• This is a communication and education process – in both directions -- between industry and code and fire experts.
Where We Are Headed
• Awareness, training and education for emergency responders is essential • New product monitoring and code changes are critical
2016 ICC Annual Conference Education Programs Kansas City, MO 38 Summary
. The world of refrigerants (residential, commercial, refrigeration) is changing
. New refrigerants are flammable (or mildly flammable)
. New refrigerant safety standards are being written
. Flammable refrigerants may be the only option and in a time frame shorter than will allow the building and fire codes to be implemented
. The refrigerant industry is asking for help to reach out to the fire safety and code communities to get their advice and cooperation
Questions/Comments?
2016 ICC Annual Conference Education Programs Kansas City, MO 39 Additional Resources . American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) . www.ashrae.org . International Institute of Refrigeration . www.iifiir.org . Global Refrigerant Management Initiative . Alliance for Responsible Atmospheric Policy . www.arap.org . Air‐Conditioning, Heating and Refrigeration Institute . www.ahrinet.org . Brazilian Association for HVAC‐R . www.abrava.com.br
Exam
2016 ICC Annual Conference Education Programs Kansas City, MO 40