Secondary Loop Mobile Air Conditioner(SL-MAC) Demonstration Project

39th Open-Ended Working Group, Bangkok, Thailand13 July 2017

Drs. Stephen O. Andersen & Nancy J. ShermanInstitute for Governance & Sustainable Development (IGSD)

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• EU MAC Directive requires GWP <150 after 2016 for newautomobiles sold in the European Union

• US EPA offers credit toward fuel mileage standards for lowGWP

• US EPA lists HFC-134a as unacceptable in passenger carsand light-duty trucks as of Model Year 2021

• Japan HFC regulations require low GWP MACs after ModelYear 2023

• Kigali HFC Amendment will Phase Down Worldwide

Market Drivers of HFC-134a Phasedown in MACs

Atmospheric Impact of Mobile Air Conditioning

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R134a (HFC)

Atmospheric degradation products

+

HCOFCOF

HFTFA

Leakage

Indirect GHG emissionsCO2 from exhaust(About 4% to 20% of fuel use is for air conditioning; depending on climate and traffic congestion)

Leakage of high Global Warming Potential (GWP) refrigerant to the atmosphere(through AC Hoses / Joints / Servicing / Accidents / End-of-Life)

Direct Greenhouse Gas (GHG) emissions

Atmospheric Degradation ProductsCOF, HCOF, HF, TFA

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• Three refrigerant replacements approved by the USEPA SNAP also satisfy the EU F-Gas Directive (GWP<150)

• Safe use of HFC-152a requires secondary-loop for active safety system to prevent refrigerant leakage into the car interior

•*GWP from Intergovernmental Panel on Climate Change Assessment (IPCC) Assessment Report 5 (AR5)

Technical Options to Replace HFC-134a in MACs

SNAP / F-Gas Option

GWP Efficiency TFA Flammable Application Patent

HFO-1234yf < 1 Good Yes Slightly Yes

Carbon Dioxide -CO2

= 1 Poor @ High Ambient Temperature

No No No

HFC-152a = 138 Better No Yes No

Important Differences in Refrigerant Performance

• HFO-1234yf is ~5 to ~8% less energy efficient than HFC-134a, but added internal heat exchanger can offset up to 7%; thus the proper economic analysis adds the cost of the internal heat exchanger, if required, to the added cost of HFO-1234yf refrigerant

• HFC-152a is ~10% more efficient than HFC-134a, but an internal heat exchanger does not increase capacity and fuel efficiency

• HFO-1234yf charge is 10%, and HFC-152a 40%, smaller than HFC-134a

17HX-0076 5

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Secondary Loop System vs Direct Expansion System

Direct expansion systemAndersen et al., 2014

Secondary loop systemAndersen et al., 2014

SL-MACs use refrigerant to chill a fluid (coolant) that is circulated inside the car for comfort; a reduced charge of flammable refrigerants can be used more safely in systems with less emissions from fewer fittings and shorter refrigerant hoses.

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UNEP CCAC

TATA Motors

MAHLEIGSD

• Apply SL-MAC system with improved Power Train Control logic to reduce short-lived climate pollutants (SLCPs) and maximize energy efficiency advantage

• Financial support by UNEP, as part of a climate change project of the Climate and Clean Air Coalition (CCAC)

• TATA Aria 2.2L Dicor is selected vehicle with front and rear A/C system

• Technical Advisors: California Air Resources Board (CARB), Chemours, Chrysler, Fiat, General Motors, Jaguar Land Rover, Neutronics Refrigerant Analysis, HF Consultancy, Natural Resources Defense Council (NRDC), Mobile Air Conditioning Society Worldwide (MACS), SAE International, Sun Test, TERRE Policy Centre, National Renewable Energy Laboratory (NREL), University of Maryland, and Valeo.

Baseline Direct Expansion (DX) Dual AC System

Technology Demonstration: Secondary Loop for Flammable Refrigerants

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• Time to comfort in SL-MAC system is demonstrated to be equivalent to direct expansion (DX) systems despite the need to cool the intermediate coolant

• Added components increase vehicle weight and fuel use (very minor compared to overall fuel economy improvement obtained) and require extra effort to recycle at end of vehicle life

• It is always challenging to attribute measured improvements in fuel efficiency to specific design features; some innovations in the demonstration vehicle can also be applied to DX systems

Challenges: Secondary Loop System

Unique to SL-MACs Both SL- or DX- MACs

Regenerative cooling, powered cooling controlled for least fuel use, cold storage, low-cost multiple cooling points to reduce the energy use needed for comfort

Compressor preferentially engaged on deceleration, water flow to heater controlled by valve in hot weather, and other enhancements to-be-determined during demonstration

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Advantage

• Less Refrigerant at Lower Cost Per Vehicle (e.g. 2 or > cooling points)

• Manage Refrigerant Risk

• Use Stored Cold Energy

• Coolant Distributed Cooling

• Easy Extension to Heating

• Improved Noise, Vibration, and Harshness (NVH)

• Deceleration Cooling

• Potential Cost Advantages to Vehicle Owners

Disadvantage

• Additional Components and Mass

• Package Size (parts + volume)

• Lower Coefficient of Performance (COP) that can be mitigated by SL-MAC engineering choices

Key Project Objective: Increase the SL-MAC coefficient of performance (COP)and Life-Cycle Climate Performance (LCCP) beyond that of a DX system

with Latest Thermal and New Powertrain Technology

Secondary Loop advantages and disadvantages over Direct Expansion System

Economic Framework

• Manufacturing• Secondary loop (SL) is the economic choice when added SL components cost less

than the difference between HFO-1234yf and HFC-152a refrigerant costs

• Ownership• SL is the economic choice if cost savings from less frequent service and fuel

savings are greater than the added cost of the system components

• Sensitivity Analysis is Essential• Declining cost of refrigerants from mass production and competition

• Application patents for HFO-1234yf in MACs will expire by 2023 in most markets

• Both HFO-1234yf and HFC-152a qualify for the U.S. low-GWP credit toward fuel efficiency

• Credits for off-cycle fuel savings may be a game-changer in favor of SL-MACs (deceleration cooling and prolonged comfort in vehicles with stop/start)

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Preliminary Findings SL-MAC Economics

• Manufacturing• Single-point cooling

• HFO-1234yf with internal heat exchanger (if necessary) is likely the least cost short-term manufacturing option where engine real estate is limited

• Two or more cooling points- HFC-152a is clearly the least cost system, with co-benefits in durability and customer satisfaction

- Ownership• SL-MAC cost advantages of less frequent service and fuel savings

overwhelms manufacturing cost disadvantage

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March 2017 Refrigerant Cost Comparison

Refrigerant OEM cost/kg Retail cost/kg Cost charge Cost recharge

HFC-134a $8.00 $16.79* $5.60 (700 grams) $11.76 (700 grams)

HFO-1234yf $80.00 $220.00* $50.40+ (630 grams) $138.6+ (630 grams)

HFC-152a ~$5.00 ~$10.00 ~$2.10+ (420 grams) ~$4.40+ (420 grams)

*13 March 2017 Refrigerant Prices O’Reilly Auto Parts: 10 pounds HFO1234yf @ $199.00; 30 pounds HFC-134a @ 229.99+Accounting for the 10% and 40% reduction in system charge for HFO-1234yf and HFC-152a, respectively

Refrigerant OEM cost/kg Retail cost/kg Cost charge Cost recharge

HFC-134a $8.00 $16.79* $12.80 (1600 grams) $26.86 (1600 grams)

HFO-1234yf $80.00 $220.00* 115.2+ (1440 grams) $316.8+ (1420 grams)

HFC-152a ~$5.00 ~$10.00 ~$4.80+ (960 grams) ~$9.60+ (960 grams)

Indicative Single-Point Automobile & Light Truck Systems

Indicative Multi-Point & Heavy Truck Systems

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MAC Kigali Amendment Business Opportunities

• Investment Certainty of Global Transition from HFC-134a• Anticipate HFC-134a restriction in export markets

• Reduced Emissions in Servicing and End-of-Life• Training and tools for servicing with HFC-134a and new

refrigerants

• Agreed Incremental Cost of Re-Tooling manufacturing in A5 Parties Paid by Montreal Protocol Multilateral Fund (MLF)

• “Downstream” costs of MAC service and Fuel Use

Thank you for your attention!

SL – MAC System: Concept Demonstration Model

Questions

Backup Slides Follow

Team Members

• Tata Motors Ltd (TML) - Sangeet Kapoor, PrasannaNagarhalli, Jagvendra Meena

• MAHLE - Sourav Chowdhury, Timothy Craig, Lindsey Leitzel

• Institute for Governance & Sustainable Development (IGSD) – Dr. Stephen O. Andersen, Dr. Nancy J. Sherman,Melinda Soffer

• JAB Consulting – Jim Baker

Cooling Degree Days & Population

17Source: Davis et al, Proceedings of the National Academy of Sciences, 2015

Kigali HFC Amendment

• Unanimous Agreement of all Nations

• Phase-down HFCs on Differentiated Schedules that can be Accelerated• Most Developed Countries First

• Russia and Affiliated Countries Second

• Vast Majority of Developing Countries Third

• Developing Countries in High Ambient Regions Last

• Increased Energy Efficiency Anticipated (SAE LCCP Metric for Vehicles)

• Financing of Agreed Incremental Costs for Developing Countries Qualified Under Article 5 of the Montreal Protocol

19Stephen A Montzka, NOAA/ESRL, 2006

The Montreal Protocol Phaseout of Ozone-Depleting Substances (ODSs)

The Montreal Protocol has slowed and reversed the accumulation of ozone depleting substances (ODSs) in the stratosphere, as measured by effective stratospheric chlorine amounts.

The Montreal Protocol ODS Phaseout Protects Climate!

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Guus JM Velders, Stephen O Andersen, John S Daniel, David W Fahey, and Mack McFarland, PNAS, 2007

The Montreal Protocol reduced net GWP-weighted emissions from ODS in 2010 by 11 Gt CO2-eq yr-1. This is 5-6 times the reduction target of the first commitment period (2008-2012) of the Kyoto Protocol.

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Kigali Amendment: HFC Phasedown Schedule in Article 5 Parties (mostly developing countries)

Source: OzonAction Fact Sheet The Kigali Amendment to the Montreal Protocol: HFC Phase-down, 2016

Kigali Amendment: HFC Phasedown Schedule in Non-Article 5 Parties (mostly developed countries)

Source: OzonAction Fact Sheet The Kigali Amendment to the Montreal Protocol: HFC Phase-down, 2016

Extraordinary Benefits of HFC Phasedown

Source: UNEP, Montreal Protocol and the Green Economy (2012) 23

The Kigali Amendment is the Startthat will be Strengthened!

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Protocol Drivers

• The 2016 Kigali Amendment – Reduction in Short Lived Climate Pollutants (SLCP) – HFCs

• The 1997 Kyoto Protocol already controls HFC emissions

• The 2016 Montreal Protocol Amendment will control HFC production and consumptionand will finance the transition by developing countries to lower GWP refrigerants andhigher energy efficiency

Market Drivers

• EU MAC Directive requires GWP <150 after 2016 for new automobiles sold in theEuropean Union

• US EPA offers credit toward fuel mileage standards for low GWP

• US EPA lists HFC-134a as unacceptable in passenger cars and light-duty trucks as ofModel Year 2021

• Japan HFC regulations require low GWP MACs after Model Year 2023

Protocol & Market Drivers of HFC-134a Phasedown in MACs

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• Three refrigerant replacements approved by the USEPA SNAP also satisfy the EU F-Gas Directive

(GWP<150)

•*GWP from Intergovernmental Panel on Climate Change Assessment (IPCC) Assessment Report 5 (AR5)

• HFO-1234yf, although costly (bulk cost increased by 10~12 times), is leading with 35 manufacturers, 125

models so far 24 million vehicles sold by year end 2016

• Audi and Daimler selected CO2 (R744) based on non-flammability, and limited regular production has

started on selected models.

• Automobile companies know how to safely use flammable fluids (fuel, hydraulic fluid, motor oil, brake

fluid, antifreeze, and windshield cleaning fluid are all flammable)

Technical Options to Replace HFC-134a in MACs

SNAP / F-Gas Option GWP Efficiency TFA Flammable Application Patent

HFO-1234yf < 1 Good Yes Slightly Yes

Carbon Dioxide - CO2 = 1 Poor @ High Ambient No No No

HFC-152a = 138 Better No Yes No

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S.No Test Test ConditionBaseline Test

Status

1 Air discharge measurement Front and Rear-All blower speed Completed

2Stationary AC performance test in Moderate Ambient-(Open Door Close Door)-Max Blower, Max Cool

35°C, 40 % RH Completed

3Stationary AC performance test in Severe Ambient-(Open Door Close Door)-Max Blower, Max Cool

45°C, 40 % RH Completed

4Transient AC Performance test in Moderate Ambient-Max Blower, Max Cool

35°C, 40 % RH, 1000 W/m2 Solar Load

Completed

5Transient AC Performance test in Severe Ambient-Max Blower, Max Cool

45°C, 40 % RH, 1200 W/m2 Solar Load

Completed

6 Kolkata City cycle AC Performance test-Max Blower, Max Cool 38°C, 50 % RH, 800 W/m2 Solar Load Completed

7 Mumbai City Cycle AC Performance test-Max Blower, Max Cool 40°C, 60 % RH, 800 W/m2 Solar Load Completed

8 Compressor power consumption35°C, 40 % RH, 1000 W/m2 Solar Load

Completed

9Thermal Comfort - Moderate Ambient Transient AC Performance test-Max Blower, Max Cool

35°C, 40 % RH, 1000 W/m2 Solar Load

Completed

10Thermal Comfort - Severe Ambient Transient AC Performance test –Max Blower, Max Cool

45°C, 40 % RH, 1200 W/m2 Solar Load

Completed

11 Fuel Economy and Emmision Test Indian Drive Cycle Completed

Baseline Test Plan

TATA Aria Baseline Testing

Component Level Tests

- Individual Components: Evaporators (F & R), Condenser- Chiller-Cooler Combination

System Bench Testing (per GreenMAC LCCP criteria)

Vehicle Wind Tunnel Testing

ChillerCooler Pump

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Energy Benefits of Secondary Loop Simulated Fuel Economy With Cold Storage

Conditions: A. No A/CB. Continuous A/C with Cabin Soak to Ambient ConditionC. B + Compressor Disengaged at Speed = 0 (Engine runs at idle)D. B + Compressor Disengaged at Speed = 0 OR Acceleration >0

FTP75 (mph) NEDC (kph) SC03 (kph)

Demonstrates the Potential Fuel Economy Benefit of SL-MAC

A B C D

Fuel Econ (mpg) No A/C Continuous A/C Compressor Stop at idle Compressor Stop at Idle+Accl. Gain = (D-B)/Bx100 (%)

FTP75@28°C 23.2 19.7 19.8 20.9 6.1%

NEDC@28°C 20.1 17.4 17.5 19.4 11.5%

SC03@35°C 18.1 15.4 15.5 17.3 12.3%

Chart of Simulated Fuel Economy Improvement, Dr. S. Chowdhury, MAHLE

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Project Plan

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2018

Q3 Q4 Q1 Q2 Q3 Q4 Q1

Baseline Vehicle Assessment

Component & System Development

Vehicle Build,Emissions & Wind Tunnel Tests

PowerTrain Logic Implementation

Road and Tunnel Evaluation in India

Final Energy Analysis and Report

20172016Task Name

MAHLE Receives Vehicle

TML Receives Vehicle