# Technical Support Document for Acceptability Listing of HFO

- 1234 yf for Motor Vehicle Air Conditioning in Limited Heavy

- Duty Applications

P REPARED FOR 

### :

Stratospheric Protection Division Office of Air and Radiation U.S. Environmental Protection Agen cy Washington, D.C. 20460

P REPARED BY 

### :

ICF International 1725 Eye Street, NW Washington, DC 20006

M ARCH 

### 21, 201 61 

## 1. Introduction
Motor vehicle air conditioner (MVAC) systems cool the passenger compartment of passenger cars, light

duty (LD) truck s, heavy

- duty vehicles (HDV) , off

- road vehicles, buses, and passenger rail vehicles. The MVAC sector historically relied on CFC

- 12, and to a more limited extent, HCFC

- 22 in passenger rail and buses, both of which are ozone depleting substances (ODS). In ad vance of the 1996 phaseout of CFC

- 12 and the continued phaseout of HCFCs, the U.S. MVAC industry largely transitioned away from ODS by 1994, relying most heavily on a high

- GWP refrigerant, HFC

- 134a. Today, HFC

- 134a remains the predominant refrigerant; howe ver, low

- GWP alternatives are entering the U.S. market for light

- duty vehicles ( LDVs ) , facilitated by approval of alternatives, including hydrofluoroolefin (HFO)

- 1234yf
, by EPA’s SNAP p rogram and the availability of air conditioning credits to meet greenho use gas ( GHG ) standards for LD Vs. In 2011, EPA’s SNAP p rogram found HFO

- 1234yf acceptable, subject to use conditions, in MVAC systems for new passenger cars and LD trucks. EPA is now evaluating the use of HFO

- 1234yf in MVAC systems of limited types of HD Vs , specifically medium

- duty passenger vehicles (MDPV)
, heavy

- duty (HD) pickup trucks
, and complete HD vans. The purpose of this t echnical s upport d ocument i s to provide the following:

• Summarize b ackground information on MDPVs and HD pickup trucks and vans i n terms of vehicle types, market size, and MVAC characteristics in the United States ;

• A nalyze the ratio of MVAC refrigeran t charge size to passenger compartment volume for these vehicles as compared to LDVs ; and

• Conduct a q ualitative analysis of risks ant icipated for these vehicle types as compared to risks assessed for the use of HFO

- 1234yf in LDVs

. 

## 2. Background Information

This section provides b ackground information on the current U.S. market for MDPVs , HD pickup trucks
, and HD vans , specifically the following:

• Vehicle Types

• Fleet Estimates

• MVAC Characteristics


### 2.1 Vehicle Types

Vehicles are typically classified by their gross vehicle weight rating (GVWR), which is the maximum loaded operating weight of the vehicle including cargo and passengers. HDVs include all on

- road vehicles rated at or above 8,500 pounds GVWR which meet the criteria outlined in 40 CFR 86.1803

- 01

. HDVs with GVWR between 8,501

– 10,000 pounds and 10,001

– 14,000 pounds are classified as Class 2b and Class 3 vehicles, respectively. T his analysis includes C lass 2b and 3 MDPVs, 1 HD passenger vans, HD cargo vans, and HD pickup trucks , but does not consider any vocational vehicles that may also be in included in the GVWR range (e.g., chassis cabs , utility “bucket” trucks, refuse trucks, a mbulance s , tow trucks, and dump truck s ). For the purposes of this analysis, EPA is not considering vehicle types with a GVWR above 14,000 pounds.

1 MDPVs include passenger vans with GVWR between 8,501 pounds and 14,000 pounds. While MDPVs are classified as HD vehicles by GVWR, their fuel economy and GHG emissions are regulated with LDVs.2 Figure 1 . Examples of Class 2b and 3 Van and Pickup Truck

Source: EPA (2011b)
HD Vs are commonly used as work vehicles . HD pickup trucks are typically the HD versions of the ir higher

- volume LD counterparts (ICCT 2015). For example, the Silverado 1500, Ram 1500, and Ford F

- 150 are the LD counterparts of the HD Silverado 2500/3500, Ram 2500 /3500, and Ford F

- 250/F

- 350 /F

- 450 pickup trucks. Approximately 90 percent of HD pickups and HD vans are 3⁄4

- ton and 1

- ton pickup trucks, 15

- passenger vans, and large work vans that are sold by vehicle manufac turers as complete vehicles ( EPA and NHTSA 2011 a ). In the United States, MDPVs, HD pickup trucks, and HD vans are manufactured by Ford, General Motors (GM) , Fiat Chrysler Automobiles (FCA), Nissan, and Daimler

. The following table provides the descriptions
, classifications , and models of MDPVs, HD pick up trucks and HD vans

. Table 1 . Descriptions and Classifications of MDPVs, HD Pickup Trucks , and HD Vans

Vehicle Class Gross Vehicle Weight Rating (GVWR) (lbs) Vehicle Types Vehicle Models

Class 2b 8,501

– 10,000 Van, Passenger Chevrole t Express Passenger GMC Savana Passenger Ford E

- Series Econoline Nissan NV Passenger Van, Cargo Chevrolet Express Cargo D aimler Sprinter GMC Savana Cargo Nissan NV 2500 HD Cargo Nissan NV 3500 HD Cargo Ram Promaster Pickup Truck Chevrolet Silverado 2 500 Do dge Ram 2500 GMC Sierra 2500 Denali GMC Sierra 2500 HD Class 3 10,001

– 14,000 Van, Passenger Ford Transit W agon XL/XLT Van, Cargo Ford Transit Van Pickup Truck Chevrolet Silverado 3500 Ford F

- 250 Ford F

- 350 Ford F

- 450 GMC Sierra 3500 HD Ram 2 500 SLT Ram 3500 SLT Ram 3500 Tradesman3 As presented in Table 1, in the Class 2b a nd Class 3 vehicle markets, Ford produces the F

- 250, F

- 350, and F

- 4 50 “Super

- Duty” pickup trucks, GM produces the Silverado, Sierra HD series HD pickup trucks, and FCA produ ces the Ram HD pickup truck series. Class 2b and Class 3 HD vans are categorized as either
passenger or cargo vans, with vehicle model series often serving both functions depending on the inclusion of additional rows of passenger seats in the extended sect ions of the vehicle (e.g., Nissan NV series). The HD van market includes the Transit (Ford) which replaced the E

- Series Econoline (Ford ), Savana and Express series (GM), Promaster (FCA) , N V series (Nissan), and Sprinter (Daimler). Table 2, below, presents the estimated market share for HD pickup trucks and vans (EPA 2015).

Table 2

. Market Share for HD Pickup Trucks and HD Vans a

Manufacturer Style 2015 M odel Y ear (MY) Market Share Daimler

Van 3% Fiat 2% Ford 16% General Motors 12% Nissan 2% Daimler

Pickup <1 % Fiat 14% Ford 28% General Motors 23% Nissan <1 %

a Equivalent information on MDPVs is not included because it was not readily available

. 

### 2.2 Vehicle Market

Available information on vehicle market estimates (i.e
., vehicle sales or new registrations ) for the HDV types included in this analysis within the United States are presented in this section . According to ICCT (2015), Class 2b and Class 3 HD pickup trucks and HD vans represent more than 50 percent of all HDV sales in the United States. The figure below was developed by ICCT (2015) using three data sources [ i.e., Wards ( 2012 ) , Automotive News ( 2014 ) , and BEA ( 2014) ] on total new vehicle registrations by calendar year of vehicles less than 14,001 pounds GVWR. B y subtracting th e number of registrations of LDVs (i.e., vehicles less than 8,501 pounds) by model year (MY) available from EPA from the data on total sales of vehicles less than 14,001 pounds
, there were approximately 450,000 newly registered Class 2b and Class 3 vehicles in 2010, 1.0 million i n 2012, and 1.2 million in 2013 (ICCT 2015)

.4 Figure 2 . Total new Class 1

– 3 vehicles (i.e., under 14,001 GVWR) and total LDVs

Source: ICCT (2015) The following table summarizes readily av ailable data on Class 2b and Class 3 vehicle sales or new registrations from 2009

– 2015. The average total annual sales of Class 2b and 3 vehicles between 2009 and 2015 was approximately 740,000 vehicles , with estimates ranging from a high of 1.2 million in 2013 to a low of 450,000 in 2010

. D iscrepancies between data sources are likely due to overlap of vehicle categories across various sources. F or example
, some estimates only include HD pickup trucks and vans while other sources include all Class 2b and Class 3 vehicles.
Table 3

. Vehicle Registrations or Sales of Class 2b and Class 3 Vehicles from 2009

– 2015

Year Class 2b Sales Class 3 Sales Total Sales Source
2009

- 111,704 b

- US DOE 2011

2010 590,000 200,000 790,000 US EPA and NHTSA 201 5

- - 450,000 ICCT 2015

- 160,000

- ORNL 2015

- - 580,000 ICCT 2015 2011

- 190,000

- ORNL 2015

2012 - - 1,000,000 ICCT 2015 340,000 170,000 510,000 Polk 2013

- 220,000

- ORNL 2015

2013 - - 1,200,000 ICCT 2015

- 250,000

- ORNL 2015 2014 506,989 131,120 638,109 EPA & NHTSA 2015 2015 500,000 150,000 650,000 EPA & NHTSA 20155 

### 2.3 MVAC Characteristics

HD pickup trucks and HD vans share many design similarities with their lighter counterparts, including their vehicle design, work attr ibutes, and technology availability (ICCT 2015). The MVAC s ystems in these vehicles as well as MDPVs are very similar to those used in LD applications. Differences may exist in terms of cooling capacity (e.g., based on cabin volume) , system layout (e.g., t he number of evaporators), and the durability requirements due to longer truck life (EPA & NHTSA 2011 b ). MVAC systems in HD pickups and HD vans generally have a similar configuration and use similar components as their lighter counterparts. The refrigerant capacity (i.e., charge size) of MVAC systems in both LD and HD vehicles vary by vehicle type and cabin size

. A range of reported estimates of charge sizes of MVAC systems using R

- 134a in MDPVs, HD pickups and HD vans in comparison to LD vehicles are
summa rized below.
Table 4

. HFC

- 134a Refrigerant Charge Sizes for LD Vehicles, MDPVs, HD Pickups , and HD Vans End

- Use Charge Size ( g rams ) LD Vehicles 390

– 1,220 HD Van, ( Passenger and Cargo) 800

– 1,600 HD Pickup Truck 600

– 765 Sour ces: Autozone (2015), ABI (2014), Ford (2007), Ford (2014), Ford (2015 b ), TechChoice Parts (2012) , ICF (2008)

Some HD vans and other types of HDVs that are not included in this analysis have auxiliary AC systems, which are separate from the main AC syste m that is traditionally mechanically gear

- or belt

- driven by the base engine of the vehicle (EPA & NSTSA 2011). These auxiliary systems are often installed in addition to the main AC system (e.g., in the rear passenger or cargo area) and are not considered in this analysis. 

## 3. Refrigerant charge to passenger compartment volume ratio s
This section presents information on the highest refrigerant charge to passenger compartment volume ratios for the HD vehicle types addressed in this document and for LDVs add ressed in IC F (2009) . T his analysis considered 38 models of vehicles from 5 manufacturers (i.e., Ford, FCA, GM, Nissan, and Daimler) in addition to the vehicles considered in 2009

. Refrigerant charge size data were obtained from various sources including p ublically available sources developed by manufacturers, refrigerant capacity catalogs, and automotive store websites. The range of charge sizes for each vehicle type is presented above in Table 4.

P assen ger compartment volume data were largely obtained fr om the specifications listed on the respective manufacturer websites. In some cases where total compartment volumes were not exactly provided, they were estimated using the interior dimensions and the methods outlined in 40 CFR 600, Subpart D. 2

T he follow ing table presents the highest ratios identified for a variety of vehicle types, with the ratios highlighted in green to indicate those for the HDVs being considered in this document

. . The highest ratio for all HD vehicle types included in this analysis is 410 g /m 3 in HD pickup trucks (shown in bold font in Table 5 ), which is less than the maximum ratio identified in the analysis for HFO

- 1234yf in LDV s in two seaters (i.e., 641 g/m 3 ) (also shown in bold)

.

2 Passenger compartment volume can be calculated as the sum of [ (Head Room x Shoulder Room x Leg Room)/1728] for all rows of seating.6 Table 5 . Vehicles with the Highest Ratio of Refrigerant Charge to Passenger Compartment Volume in each Vehicle Type

Vehicle Type Passenger Compartment

Size (m 3 ) a MAC Charge Size HFC

134a (grams) b Ratio of HFC

134a Charge to Compartment Volume (g/m 3 ) Manufacturer Model c

HD Pickup 1 .87 765 c 410 Ford F450 (Regular) (MY 2014) HD Van, Cargo 9.51 1,600 168 Chevrolet Express Cargo HD Van, Passenger 6.50 1,600 246 Chevrolet Express Passenger Two seaters 1.42 907 641 Mercedes

- Benz Sl65 AMG (MY 2007) Small pickup trucks 1.48 940 633 For d Ranger S.U.V. 3.01 1250 415 Mercury Mountaineer (W/ Aux Heat) Standard pickup trucks 1.59 632 398 Toyota Toyota Tacoma Prerunner Compact cars 2.63 936 355 Mercedes

- Benz CLS Class (MY 2007) Subcompact cars 2.29 794 346 BMW 650i And M6 (MY 2007) Minic ompact cars 2.10 725 346 Jaguar Jaguar XKR Midsize cars 2.72 936 343 Mercedes

- Benz E Class (MY 2007) Large cars 2.94 794 270 BMW 750i (MY 2007) Small station wagons 2.66 670 252 Pontiac Vibe Minivan 4.42 1,100 249 Dodge Grand Caravan SXT Wagon Midsize station wagons d 3.06 475 155 Kia Rondo

a Source s : ICF (2008) and vehicle manufacturer websites. Otherwise, v alue was estimated using methods at 40 CFR 600, Subpart D.
b Source s : Mot or Information Systems database unless otherwise noted.

c Autozone (201 5)

c All models are MY 2008 unless otherwise noted.
d Data were available for only 1 midsize station wagon . By default it has the ‘highest’ ratio.


## 4. Qualitative Risk Analy sis

H FO

- 1234yf is flammable when its concentration i n air is in the range of 6. 2 percent to 12.3 percent by volume ( 6 2 ,000 ppm to 123,000 ppm)

. In the presence of an ignition source (e. g., spark , open flame ), a fire could occur when the concentration of HF O

- 1234yf is wit hin these flammability limits. To determine whether the flammability or end

- use exposure of HFO

- 1234yf would be a concern for LDV passengers, a reasonable worst

- case scenario analysis was performed in 2009 to model the catastrophic release o f the refrigerant into a vehicle (ICF 2009)

. Two key inputs to the model were passenger compartment volume (i.e., the space into which the refrigerant would leak) a nd the refrigerant charge size. Because passenger compartment volumes and refrigerant charge sizes can vary widely from model to model, ICF used the highest ratio of charge size to com partment volume identified (see section above) as the input into the model. The highest refrigerant charge to passenger compartment ratio for LDVs was determined as approximately 641 g/m 3

. This section presents a q ualitative ana lysis of risks anticipated for the use of HFO

- 1234yf in the limited HDV types discussed in th is document as compared to the LDV types considered in the existing analysis conducted on the use o f HFO

- 1234yf in LDVs (ICF 2009 ; Gradient 2008 )

. To assess the potential risks associated with the use of HFO

- 1234yf in LDVs, ICF International (ICF 2009) and an SAE International Cooperative Research Program (CRP) (Gradient 2008) conducted risk assessments
, using worst

- case scenario box modeling and Computational Fluid Dynamics (CFD) modeling, respectively . The
assessments evaluated the end

- use exposure and flammability risks of using HFO

- 1234yf in LDV s by comparing concentrations of HFO

- 1234yf in the passe nger compartment with the lower flammability limit ( LFL ) of 62,000 ppm following a leak from the MVAC system

.7 The SAE CRP ( Gradient 2008) conducted CFD modeling using a Ford Crown Victoria, the same vehicle model used by EPA to evaluate the use of R

- 15 2a and CO 2 (R

- 744) in LDV MVAC systems ( Blackwell et al. 2006 ) , which has a charge to compartment volume ratio of 223 g/m 3

. 3 The SAE CRP concluded that there was a very l ow flammability risk due to the extremely low probability of achieving a con centration of HFO

- 1234yf above the LFL at the same time as having a sufficiently high energy source and the presence of oxygen to result in refrigerant ignition (Gra dient 2008)

. In ICF (2009), the worst

- case scenario evaluated was the Mercedes SL65 AMG tw o

- seater , which was selected because it was identified as having the greatest refrigerant charge per passenger compartment volume ratio of all LDVs evaluated (i.e., 641 g/m 3 ). 4 T o prevent against the risk of fire o r explosion, ICF (2009) recommen ded in sup port of EPA ’s proposed rule to list HFO

- 1234yf for use in LDVs that all HFO

1234yf MVAC systems, particularly in vehicles with high refrigerant charge to compartment volume ratios, should be designed to avoid occupant exposure to concentrations of HFO

- 12 34 yf above 62,000
ppm in the passenger compar tment for more than 15 seconds. EPA did not finalize this recommendation as a use condition for LDVs because it was determined that another use condition , which requires manufacturers to meet all of the safety req uirements in the standard SAE J639, “Safety Standards for Motor Vehicle Refrigerant Vapor Compression Systems
, ” sufficiently mitigate s the risk of fire or explosion (March 29, 2011; 76 FR 17488)

. ICF (2009) also concluded that acute exposure to elevated

co ncentrations of HFO

- 1234yf is not expected to be a toxicological concern in humans who are exposed following a worst

- case, accidental relea se of the total MVAC refrigerant charge. The results of the analysis in Section 3 of this document indicate that t he highest ratio for all MDPVs, HD pickup trucks and HD vans is 410 g/m 3 in the Ford F

- 450, which is 231 g/m 3 less than the maximum ratio used in the worst

- case scenario in ICF (2009) (i.e., 64 1 g/m 3 )

. As a result, the toxicity and flammability risks fro m using HFO

- 1234yf in MDPVs, HD pickup trucks
, and complete HD vans will be lower than those from HFO

- 1234yf used in LDVs because of the much higher refrigerant charge to passenger compartment volume ratio s . The analysis conducted on LDVs is sufficiently c onservative to account for toxicity and flammability risks that could occur from the use of HFO

- 1234yf in MDPVs, HD pickup trucks, and complete HD vans. Based on the discussion presented here, and the previous analysis, ICF believes that the risk of advers e health effects and fire are minimal if HFO

- 1234yf MVAC systems are manufactured and used in accordance with use conditions, and installed in MDPVs, HD pickup trucks
, and complete HD vans in accordance with industry standards and recommendations.

ICF con cludes that the most co nservative scenarios modeled by ICF (2009) for HFO

- 1234yf in LDVs is sufficiently conservative to account for potential risks of HFO

- 1234yf in MDPVs, HD pickup trucks
, and complete HD vans

. Therefore, the use of HFO

- 1234yf in the lim ited HDV types analyzed in this document indicate that potential exposure from a refrigerant leak int o the passenger compartment is not expected to present an unreasonable risk to drivers, passengers or first responders in the case of an accident or

co llision

.

3 The charge size and passenger compartment volume of the Ford Crown Victoria used in the CFD m odeling were 691 grams and 3.1 m 3 , respectively (Gradient 2008).

4 The charge size and passenger compartment volume of the Mercedes SL65 AMG two

- seater used in the worst

- case scenario box modeling were 907 grams and 1.4 m 3 , respectively ( ICF 20 09 ).8 

## 5. References

Austin Baker Industries (ABI), Inc. 2014. 2014 ABI Oil and Refrigerant Capacity Catalog. Available online
at: http://www.austinbaker.net/downl oads/2014/2014%20ABI%20Oil%20Catalog.pdf

. Autozone, Inc. 2015. Specifications. Available online at: http://www.autozone.com/repairinfo/specifications/specificationsMa in.jsp

. Blackwell, N., L. Bendixen, and E. Birgfeld. 2006. Risk Analysis for Alternative Refrigerant in Motor Vehicle Air Conditioning. September 2006. Available online at: http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

- OAR

- 2004

- 0488

- 0038

.

Chevrol et. 2015. Models: 2016 Express Cargo Van, 2015 Express P assenger Van, 2015 Silverado 1500, 2015 Silverado 2500HD, and 2015 Silverado 3500HD. Available online at: http://www.chevrolet.com

.
Ford Motor Company. 2015a . Model Specifications: 2016 Chassis Cab, 2016 E

- Series Cutaway, 2016 Super Duty, 2016 Transit. Available online at: http://www.ford.com

. Ford Motor Company. 2015b. 2015 Transit Owner’s Manual. Available online at: http://www.fordservicecontent.com/Ford_Content/Catalog/owner_information/2015

- Transit

- Owners

Manual

- version

- 2_om_EN

- US_05_2014.pdf

.
Ford Motor Compa ny. 2014. Body Builders Layout Book Design Recommendations. Available online at: https://www.fleet.ford.com/truckbbas/topics/2014/2014_DesRec_v1

- 1.pdf

.
Ford Motor Compa ny. 2007. R

- 134a Refrigerant Charge Capacities in Ounces. Available online at: http://www.m

- m

- s.com/ackits_public/files/refrigerantcapacities.pdf

.
Freehold Dodge. 2015. Pe rsonal communication with service technician at Freehold Do dge dealership in Freehold, NJ on September 28, 2015.

Freightliner. 2015. The 2015 Sprinter. Available online at: http://www.freightlinersprinterusa.com/files/cargo

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. Gradient Corporation. 2008. Risk Assessment for Alternative Refrigerant HFO

- 1234yf. Confidential report prepared for SAE International Cooperative Research Program 1234. February 2008.

Herb Gordon Nissan

. 2015. Personal communication with service technician at Herb Gordon Nissan in Silver Spring, MD on September 24, 2015.

ICF International. 2008. Air Conditioning Refrigerant Charge Size to Passenger Compartment Volume Ratio Analysis. Confidential Memorand um Prepared for the U.S. Environmental Protection Agency.9 ICF International. 2009. Risk Screen on Substitutes for CFC

- 12 in Motor Vehicle Air Conditioning: Substitute: HFO

- 1234yf. Available online at: http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

OAR

- 2008

- 0664

- 0038

.
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.
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. Ram. 2015. Model Specifications: 2500 Models, 3500 Models, ProMaster Cargo, Chassis Cab 3500. Av ailable online at: http:// www.ramtrucks.com

. TechChoice Parts. 2012. Refrigerant and oil capacity charts. Available online at: http://ww w.techchoiceparts.com/refrigerant

- and

- oil

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. U.S. Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA). 2015. Proposed Rulemaking for Greenhouse Gas Emissions and Fuel Efficiency Standards for Med ium

- and Heavy

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– Phase 2: Draft Regulatory Impact Analysis. June 2015. Available online at: http://www3.epa.gov/otaq/climate/documents/420d15900.pdf

. U.S. Environmental Protection Agency (EPA). 2011. Protection of Stratospheric Ozo ne: New Substitute in the Motor V ehicle Air Conditioning Sector u nder the Significant New Alternatives Policy (SNAP) Program; Final Rule. March 29, 2011. 76 FR 17488. Available online at: http://www.gpo.gov/fdsys/pkg/FR

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.

U.S. Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA). 2011a. Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium

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.