Flammable Refrigerants: The Evolving Impact on Codes

2016 ICC Annual Conference Education ProgramsKansas City, MO 1

Flammable RefrigerantsThe 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)


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


Part I:Refrigeration Concerns

Why Change?

GLOBAL WARMING POTENTIALChlorofluorocarbons (CFCs) and

Hydrochlorofluorocarbons (HCFC)

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

GLO

BAL WARMING IN

FLUEN

CE


Montreal Protocol

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

GLO

BAL WARMING IN

FLUEN

CE

Phase-out Begins January 1, 1989

GLOBAL WARMING POTENTIALChlorofluorocarbons (CFCs) and

Hydrochlorofluorocarbons (HCFC)

Hydrofluorcarbons

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

GLO

BAL WARMING IN

FLUEN

CE

Phase-out Begins January 1, 1989

GLOBAL WARMING POTENTIALHydrofluorocarbons (HFCs)


Global Demand

Source: National Oceanic and Atmospheric Administration (NOAA)

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

Developing World Deman

d for A/C and Refrigeration

High estimate

Low estimate

Developing Countries

Developed Countries

EU: Move down to low-GWP refrigerants

1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

GLO

BAL WARMING IN

FLUEN

CE

100%

20%


20202017 2018 2019

US: GWP Proposed Phaseout (EPA)

Supermarkets

Remote Condensing Units

Small vending machines

Large vending machines

Standalone low temperature devices

Central air conditioners ?

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


Part II:Refrigeration Physics

Newton’s First Law of Thermodynamics Conservation of energy: Energy cannot be created

or destroyed in chemical reaction

Refrigeration Physics

U=Q‐WWhere:

U = change in internal energyQ = heat added to the system (energy in)W = Work done by the system (energy out)


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.

.

Compressor pressurizes

refrigerant gas

Condenser, where it rejects heat to outdoors and liquefies

Moves through valves where it

expands into a gas

Draws heat from the refrigerated space

Mechanical Refrigeration Cycle


Mechanical Refrigeration: Operating Scheme (Simplified)

Refrigerated space

Usually outdoors

Fan

Mechanical Refrigeration: Definitions

• Compressor – Mechanical equipment that raises refrigerant pressure

• Condensing Unit -- Assembly of a compressor, condenser, fan motor, controls and a mounting plate

Courtesy: Danfoss.com

Courtesy: Copeland Refrigeration Units



• Expansion valve -- Adjusts refrigerant flow and pressure to satisfy all load conditions.

• Refrigerant-- Liquid or gaseous cooling medium

Courtesy: Danfoss


• CFC– Chlorofluorocarbon

• HFC -- Hydrofluorocarbon

• HCFC--Hydrochlorofluorocarbon



• 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


• 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”


• 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).

Mechanical Refrigeration: Units

Courtesy: Livescience.com

• Most residential A/C units capacity range:

• Large industrial chiller systems up to:


Tons kW Btu/hr

1 to 5 3.5‐ 17.5 12,000‐60,000

Tons kW Btu/hr

Up to 800 2,800 9,600,000

Courtesy: excaliburlpa.co.uk

Courtesy: AC2015.com


• 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


Mechanical Refrigeration: Pounds

Recharging Vessels

Courtesy: Summit Refrigerants


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.


Refrigerant Composition

Prefix Represents Examples

R Refrigerant R22, R134a, R717

May include:

C ChlorineRC317

Chloroheptafluorocyclobutane

B BromineR22B1

Bromodifluoromethane

F FluorineRFE‐36

Hexafluoropropane

H HydrogenR134a

1,1,2,2‐Tetrafluoroethane

C CarbonRC318

Octafluorocyclobutane

E EtherRE170

Dimethylether

Refrigerant Nomenclature

Numbering Series

Chemistry Examples

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


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

RN of double carbon bonds

(Placeholder omitted when zero)

Carbon Atoms(Minus 1)

Hydrogen Atoms(Plus 1)

FluorineAtoms

(N/molecule)

R 0 1 3 4

R22: Chlorofluoromethane – CHClF2

Remaining bonds not accounted for are chlorine.

*a = Isomer stability.

R134a*: Tetrafluoroethane – CH2FCF3

RN of double carbon bonds

(Placeholder omitted when zero)

Carbon Atoms(Minus 1)

Hydrogen Atoms(Plus 1)

FluorineAtoms

(N/molecule)

R ? ? ? ?

Zero double bonds(omitted)

1‐1= 0 (omitted)

1+1 = 2 2


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


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 GroupsFlammability Classification

Toxicity Group

Group A Group B

Lower Toxicity Higher Toxicity

Higher Flammability A3 B3

Lower Flammability A2 B2

Low Flammability A2L B2L

No Flame Propagation A1 B1

Increasing Toxicity

Increasing Flam

mability


ASHRAE Safety GroupsFlammability Classification

Test

At 70F and 14.7 psi Examples

A3Higher

FlammabilityLFL <0.10 kg/m3

Latent heat > 4540*

MethanePropaneButane

A2Lower

FlammabilityLFL > 0.10 kg/m3

Latent heat < 4540*HCFC-142bHFC-152b

A2LDifficult to ignite

Flame speed < 3.94”/secR-32

R1234yf

A1No Flame

PropagationNo flame propagation in air

CFC-11CFC-113R-500

* Calories per gram

ASHRAE Safety Groups

Toxicity Groups

Group A Examples Group B Examples

Lower Toxicity Higher Toxicity

No toxicity identified at concentrations ≤

400 ppm

Evidence of toxicity at concentrations

<400 ppm

A1CFC,

HCFC,B1 Seldom used

A2 R152a B2 Seldom used

A2L Most Low-GWP HFC B2L Ammonia

A3 Hydrocarbons B3 Hydrocarbons


Classification Denomination Formula Safety Classification

Inorganics

R717 Ammonia NH3 B2

R718 Water H2O A1

Hydrocarbons

R170 Ethane CH3CH3 A3

R290 Propane CH3CH2CH3 A3

Halocarbons

R11 Trichlorofluormethane CCl3F A1

Examples

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‐Tetrafluoroproene

C3H2F4 A2L

R1234yf 2,3,3,3‐Tetrafluorpropene

C3H2F4 A2L

Examples (cont’d)


Vessel Identification

Courtesy: RMS of Georgia

R‐12Dichlorofluoromethane

(CFC)

R‐22Chlorodifluoromethane

(HCFC)

ZeotropicR‐22/R152a/R‐124

(HCFC)

R‐11Trichlorofluoromethane

(CFC)

R‐113Trichlorotrifluoroethane

(CFC)

R‐13B1Bromotrifluoromethane

(CFC)


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


Codes and Standards

• ASHRAE 15– Safety Standard for Refrigeration

Systems

• ASHRAE 34– Designation and Classification of

Refrigerants

• 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

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

Codes and Standards

Machinery Rooms

Courtesy: Food Engineering Mag.com

• Construction per IBC

• Table 509– One-hour separation or A/S

• §1006.2.2– > 1,000 ft2

• Two exits or exit access

• All portions within 150 feet

• Doors swing in egress direction

– Chapter 28


International Mechanical Code

• Chapter 11 REFRIGERATION

• Design, installation, construction and repair

• Six-step design protocol

Courtesy: Arescobuyersclub.com

Courtesy: Hussung.com

International Mechanical Code

• §1103.2 Occupancy classifications• Institutional

• Public assembly

• Residential

• Commercial

• Large mercantile (O.L. > 100)

• Industrial

• Mixed occupancies


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

Courtesy: resourcecompliance.com

Liquid:liquid heat exchangers


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

• Industrial occupancies and refrigerated rooms

• Exceptions for manufacturing, food and beverage prep, meat cutting and storage

Courtesy: Texas Glacier.com


IMC Machinery Rooms

• § 1105

– Design and construction

– Ventilation requirements

• Normal/emergency

• § 1106

– Continuous ventilation for NH3

– Remote emergency shutoffs

Courtesy: sirayooth.com

Refrigerant Piping §1107

• Height above floor

• Limited building envelope penetrations

• Material limits– Steel, copper, brass, aluminum

• Valve identification

Courtesy: Stellar food for Thought.net


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 emergency ventilation

• Detection and alarm systems

Courtesy: Refrigeration Today.com



• §606.7 Warning signs• Suitable for refrigerant• Comply with NFPA 704


• §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



• 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


• 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



• System controls for flammable, toxic, highly toxic or ammonia

• § 606.11 Emergency pressure control system• Treatment and flaring systems

Courtesy: Energy‐Concepts. comCourtesy: bhtank. com

Part V:Refrigerant Proposals


GWP: Traditional Refrigerants

0

1,500

3,000

4,500

6,000

7,500

9,000

10,500

12,000

Global warming potential compared

to 1 lb

CO2

CFCs

0

1,500

3,000

4,500

6,000

7,500

9,000

10,500

12,000


to 1 lb

CO2

Existing CFC Refrigerants

Use in new equipment obsolete


CFCs Unacceptable for certain EPA applications

0

1,500

3,000

4,500

6,000

7,500

9,000

10,500

12,000


to 1 lb

CO2

Unacceptable Refrigerants

What RemainsNot EPA approved for certain applications

CFCs


to 1 lb

CO2

0

1,500

3,000

4,500

6,000

7,500

9,000

10,500

12,000

What Remains


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

– Consultants

– Retailers

– Government agencies

– Non-governmental organizations

• IFC Fire CAC reviewCourtesy: PRSEngineers.com

Courtesy: PIHO Engineering.com


• 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

Where We Are Today


• “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

Where We Are Headed


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?


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

Documents

Flammable Refrigerants: The Evolving Impact on Codes