Tao Zhan, Leela Rao, Dorothy Shimer,

Sharon Lemieux, and Tao Huai

California Air Resources Board

Update on California’s Regulatory Effo

Reduce Greenhouse Gas Emissions 

Mobile Air Conditioning

Update on California’s Regulatory Effo

Reduce Greenhouse Gas Emissions 

Mobile Air Conditioning

SAE Automotive Refrigerant and System Efficiency S

Scottsdale, Arizona, July 1
Ov

• Background• Proposed MAC requirements for Califo

Low-Emission Vehicle standards

• Contact Information
MAC Refrigerant Lifetime Mass B

Initial OEM charge

Recharge:

1) Professional servicing2) Do-it-yourself

To MAC

L

E

Accid

Ser

Con

Mass in = Mass out

To environment Not addressed
California Strategies to R

MAC GHG Emis

Vehicle GHG Emissions 

Standard (AB 1493)

(2004) Regulation on small cans of HFC-134a

(2009)

Include AC leak test 

& repair in Smog 

Check Program

Enforce fe

venting” 

HFC

Low-Emission Vehicle 

Standard, LEV III

(2010)

HD and off-road fleet

(Under development 

by US EPA)

New vehicles In-Use Fleet End-of-

Decommi

refrige

Requirements for shipping c

professional 

servicing

Environmental 

Performance Label 

(2007)

Adopted Proposed Planned
Evolution of Regu

LEV III

2009 

MY

2017 

MY

CA

US EPA Federal Rule

2012 

MY

Mandatory:• Low GWP refrigerant • Low leak• Indirect emissions limit

New Federal Rule to 

Align with LEV III?

MAC improvements earn credits for GHG emissions

Similar to California AB 1493 approach (credit method) via 

the ‘Rose Garden Agreement’

AB 1493 (Pavley)
LEV III MAC Requirem

GWP 

≤ 150 (100% for 20

150 (100% for 20

• Provides a nearly 90% direct emission reduction• Industry can choose from 3 SNAP* approved refriger

HFC-152a, R744 (CO

2), and HFO-1234yf

• Movement toward use of low-GWP refrigerant• Harmonizes with EU

* SNAP: Significant New Alternatives Policy, US EPA’s program to evaluate and regulate substitutes for ozone-depleting substances
LEV III AC Requirem

Fleet Average Leak Rate 

≤ 

• Long-term performance and consumer protection

– Low leak rate is important to maintain efficiency and reduce 

maintenance costs

– Request for comments: how to ensure adequate lubrication 

colder months for better long-term containment

• Leak rate is evaluated using SAE J2727-type standar

using low-GWP refrigerants

• 9 g/yr (refrigerant) is achievable

– 18 g/yr per US EPA, 50% reduction feasible per I-MAC– Commercially available AC platforms using premium techno

achieve 9 g/yr, per AC certification under Pavley and EnviroPerformance Label regulations

– Industry moving toward use of better technologies– Electric compressor market share will likely grow (with grow

hybrid/electric vehicles), thus further lower leakage
LEV III MAC Requirem

Indirect Emissions St

• ARB is proposing to develop a fleet average AC indi

emissions standard 

– Evaluate through a Whole-Vehicle Performance Test Proce

• ARB will propose initial adoption of US EPA’s Idle Te

procedure and AC Efficiency Credits scheme as a pl

– Amend the regulation after developing a performance test p

and AC indirect emissions standard in 2012

• Performance test benefits

– Able to evaluate all current and new technologies under rea

load and driving conditions

– Enforceable
LEV III MAC Requirement 3 (

Proposed Performance Test Pro

SC03 Driving Cycle

• Elements of proposed test procedure:

– Simulate solar load (e.g., 1-2 hour soak at 850 W 

m-2

)

– Moderate ambient cell conditions (e.g., 25

0C, 50% RH)

– Transient test cycle (e.g., SC03)– Evaluate AC during both initial cool down and steady state 

control

• Difference between CO

2 from AC-off cycle and CO

2 f

weighted average of AC-on cycles (cool down and stmust be ≤ the standard
• California’s next vehicle GHG emission standard (2017 

beyond) will be incorporated into the Low-Emission Veregulation (LEV III)

• AC elements are included in LEV III• Mandatory requirements:

– Low-GWP refrigerant– Limit on leak rate– Limit on indirect emissions (evaluated by performance test)

Su
Direct Emissions• Research Division 

– Dr. Tao Zhan, (916) 445-9495, tzhan@arb.ca.gov– Dr. Tao Huai, (916) 324-2981, thuai@arb.ca.gov

Indirect Emissions• Mobile Source Control Division

– Dr. Leela Rao, (626) 350-6469, lrao@arb.ca.gov– Sharon Lemieux, (626) 575-7067, sclemieu@arb.ca.gov

ARB Co

For more information, visithttp://www.arb.ca.gov/cc/hfc-mac/hfc-mac.htmhttp://www.arb.ca.gov/msprog/levprog/leviii/leviii.htm