UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2565 PLYMOUTH ROAD

ANN ARBOR, MICHIGAN 48105

- 2498

MEMORANDUM

SUBJECT: AC17 Results from USCAR Testing Which Demonstrate the Effect of A/C Load Reduction

on CO2 Emissions

FROM: Brian Nelson

TO: Docket EPA

- HQ

- OAR

- 20 10

- 0 799

DATE: August 13

, 20 1 2

______________________________________________________________________________

United States Council for Automotiv e Research ( USC AR) members Ford, General Motors, and

Chrysler conducted many environmental chamber test s throughout the multi

- year process of

assisting EPA and CARB in the development of the new A/C test cycle, AC17. As part of the

test programs that each manufacturer conducted, there was an effort, where possible, to

de termine if CO 2 emissions effect of A/C efficiency

- improving (and by extensi on, A/C load

reducing) technologies and control strategies could be observed using the new test cycle . It had

been noted that the SC03 test procedure , which is primarily a short

- duration, high

- A/C

- load

cycle for measuring HC, CO, and NOx emissions, was no t adequate for the purpose of measuring

relatively small changes in A/C related CO 2 emissions

. Therefore, USC AR , EPA and CARB

initiated a study in April of 2010 to develop a new cycle and test procedure

.

The tests were conducted at the Ford, GM and Chrys ler laboratories in 2010

- 2012, and are still

underway as of the writing of this memo. R esults were presented to the USCAR members at

scheduled meetings, and to EPA and CARB participants

. T he results of tests are still preliminary

in that these are “developmental”, often conducted on “development” vehicles. Furthermore,

some of the tests were conducted under conditions that may not match those that are in the LD

GHG final rule. Therefore the results should no t be used to quantify the magnitude of the effect

of any particular technology. However, they do (qualitatively) demonstrate that the AC17 cycle

is capable of detecting the lower A/C

- related CO 2 emissions which result from the incorporation

of some A/C ef ficiency

- improving technologies. In all six cases where the effect of a single

efficiency

- improving technology was isolated and compared to a base case (without the

technology), the CO 2 emissions were measurably lower for the improved technology.

EPA is grateful for USC AR participation in this extensive test program. This memo only shows

some of the preliminary results of USCAR testing, and does not represent any of the opinions of

the USC AR members. OFFICE OF

AIR AND RADIATIONE ffect of SOLAR FILM on AC17 Test Results:

Mfr. = Ch rysler

Vehicle = 2011 Dodge Avenger w ith and w ith o ut solar film

Delta AC17 result = 12.0 g/mi lower (442.4

– 430.4 g/mi) on Phase 1 (SCO3 drive cycle) and

5.3 g/mi lower (256.3

– 251.0 g/mi) on Phase 2 (HWY drive cycle) with Solar Film

Note: “Baseline” condition is A/C OFFEffect of SOLAR FILM on AC17 Test Results:

Mfr. = Ford

Vehicle = 2010 Fusion with and without solar film

Delta AC17 result = 4.0 g/mi lower on Phase 1 (SCO3 drive cycle) and 1.0 g/mi lower on Phase

2 (HWY drive cycle) with Solar FilmEffect of SOLAR FILM on AC17 Test Results:

Mfr. = Chrysler

Vehicle = Fiat 500 with and without solar film

Delta AC17 result = 47.3 g/mi lower (337.2

– 289.9 g/mi) on Phase 1 (SCO3 drive cycl e) and

12.4 g/mi lower (231.9

– 219.5 g/mi) on Phase 2 (HWY drive cycle) with Solar FilmEffect of SOLAR REFLECTIVE GLAZING on AC17 Test Results:

Mfr. = General Motors

Vehicle = Cadillac CTS with and without solar reflective glazing

Delta AC17 result = 9.2 g/mi lower (442.8

– 433.6 g/mi) on Phase 1 (SCO3 drive cycle) and 6.7

g/mi lower (277.5

– 270.8 g/mi) on Phase 2 (HWY drive cycle) with Solar Reflective Glazing

Note: “Baseline” condition is ‘solar absorbing’ glazingEffect of RECIRC and REDUCED REHEAT on AC17 Test Results:

Mfr. = Chrysler

Vehicle = Avenger with and without forced recirc and reduced reheat

Delta AC17 result = 8 g/mi lower on Phase 1 (SCO3 drive cycle) and 3 g/mi lower on Phase 2

(HWY drive cycle) with recirc and reduced reheat

Note: “ ATC72 ” data used to calculate delta AC17 resultEffect of COLD STORAGE EVAPORATOR on AC17 Test Results:

Mfr. = General Motors

Vehicle = Buick Lacrosse with and without solar reflective glazing

Delta AC17 result = 24.0 g/mi l ower (78.7

– 54.7 g/mi) on Phase 1 (SCO3 drive cycle) and 3.4

g/mi lower (20.0

– 16.6 g/mi) on Phase 2 (HWY drive cycle) with Cold Storage Evaporator

Note: “ Hot Start Test ” data used to calculate delta AC17 result