Manufacturers may generate credits applicable to the CO2 fleet average program described in Sec. 86.1865-12 by implementing specific air conditioning system technologies designed to reduce air conditioning refrigerant leakage over the useful life of their passenger automobiles and/or light trucks. Credits shall be calculated according to this section for each air conditioning system that the manufacturer is using to generate CO2 credits. Manufacturers may also generate early air conditioning refrigerant leakage credits under this section for the 2009 through 2011 model years according to the provisions of Sec. 86.1871-12(b).
(a) The manufacturer shall calculate an annual rate of refrigerant leakage from an air conditioning system in grams per year according to the procedures specified in SAE J2727 (incorporated by reference in Sec. 86.1). In doing so, the refrigerant permeation rates for hoses shall be determined using the procedures specified in SAE J2064 (incorporated by reference in Sec. 86.1) The annual rate of refrigerant leakage from an air conditioning system shall be rounded to the nearest tenth of a gram per year. The procedures of SAE J2727 may be used to determine leakage rates for HFC-134a and HFO-1234yf; manufacturers should contact EPA regarding procedures for other refrigerants. The annual rate of refrigerant leakage from an air conditioning system shall be rounded to the nearest tenth of a gram per year.
(b) The CO2-equivalent gram per mile leakage reduction used to calculate the total leakage credits generated by an air conditioning system shall be determined according to this paragraph (b), separately for passenger automobiles and light trucks, and rounded to the nearest tenth of a gram per mile:
(1) Passenger automobile leakage credit for an air conditioning system:[GRAPHIC] [TIFF OMITTED] TR15OC12.038 Where:
MaxCredit is 12.6 (grams CO2-equivalent/mile) for air conditioning systems using HFC-134a, and 13.8 (grams CO2-equivalent/mile) for air conditioning systems using a refrigerant with a lower global warming potential.
LeakScore means the annual refrigerant leakage rate determined according to the procedures in SAE J2727 (incorporated by reference in Sec. 86.1), where the refrigerant permeation rates for hoses shall be determined using the procedures specified in SAE J2064 (incorporated by reference in Sec. 86.1). If the calculated rate is less than 8.3 grams/year (or 4.1 grams/year for systems using only electric compressors), the rate for the purpose of this formula shall be 8.3 grams/year (or 4.1 grams/year for systems using only electric compressors).
GWPREF means the global warming potential of the refrigerant as indicated in paragraph (e) of this section or as otherwise determined by the Administrator;
HiLeakDis means the high leak disincentive, which is zero for model years 2012 through 2016, and for 2017 and later model years is determined using the following equation, except that if GWPREF is greater than 150 or if the calculated result of the equation is less than zero, HiLeakDis shall be set equal to zero, or if the calculated result of the equation is greater than 1.8 g/mi, HiLeakDis shall be set to 1.8 g/mi:[GRAPHIC] [TIFF OMITTED] TR15OC12.039 Where, LeakThreshold = 11.0 for air conditioning systems with a refrigerant
capacity less than or equal to 733 grams; orLeakThreshold = [Refrigerant Capacity x 0.015] for air conditioning
systems with a refrigerant capacity greater than 733 grams,
where RefrigerantCapacity is the maximum refrigerant capacity
specified for the air conditioning system, in grams.
(2) Light truck leakage credit for an air conditioning system:
[GRAPHIC] [TIFF OMITTED] TR15OC12.040
Where: MaxCredit is 15.6 (grams CO2-equivalent/mile) for air
conditioning systems using HFC-134a, and 17.2 (grams
CO2-equivalent/mile) for air conditioning systems
using a refrigerant with a lower global warming potential.LeakScore means the annual refrigerant leakage rate determined according
to the provisions of SAE J2727 (incorporated by
reference in Sec. 86.1),, where the refrigerant permeation
rates for hoses shall be determined using the procedures
specified in SAE J2064 (incorporated by reference in
Sec. 86.1). If the calculated rate is less than 10.4 grams/
year (or 5.2 grams/year for systems using only electric
compressors), the rate for the purpose of this formula shall
be 10.4 grams/year (or 5.2 grams/year for systems using only
electric compressors).GWPREF means the global warming potential of the refrigerant
as indicated in paragraph (e) of this section or as otherwise
determined by the Administrator;HiLeakDis means the high leak disincentive, which is zero for model
years 2012 through 2016, and for 2017 and later model years is
determined using the following equation, except that if
GWPREF is greater than 150 or if the calculated
result of the equation is less than zero, HiLeakDis shall be
set equal to zero, or if the calculated result of the equation
is greater than 2.1 g/mi, HiLeakDis shall be set to 2.1 g/mi:
[GRAPHIC] [TIFF OMITTED] TR15OC12.041
Where: LeakThreshold = 11.0 for air conditioning systems with a refrigerant
capacity less than or equal to 733 grams; orLeakThreshold = [Refrigerant Capacity x 0.015] for air conditioning
systems with a refrigerant capacity greater than 733 grams,
where RefrigerantCapacity is the maximum refrigerant capacity
specified for the air conditioning system, in grams.
(c) The total leakage reduction credits generated by the air conditioning system shall be calculated separately for passenger automobiles and light trucks according to the following formula: Total Credits (Megagrams) = (Leakage x Production x VLM) / 1,000,000 Where: Leakage = the CO2-equivalent leakage credit value in grams
per mile determined in paragraph (b)(1) or (b)(2) of this
section, whichever is applicable. Production = The total number of passenger automobiles or light trucks,
whichever is applicable, produced with the air conditioning
system to which to the leakage credit value from paragraph
(b)(1) or (b)(2) of this section applies.VLM = vehicle lifetime miles, which for passenger automobiles shall be
(1) or (b)(2) of this section applies.VLM = vehicle lifetime miles, which for passenger automobiles shall be
195,264 and for light trucks shall be 225,865.
(d) The results of paragraph (c) of this section, rounded to the nearest whole number, shall be included in the manufacturer's credit/debit totals calculated in Sec. 86.1865-12(k)(5).
(e) The following values for refrigerant global warming potential (GWPREF), or alternative values as determined by the Administrator, shall be used in the calculations of this section. The Administrator will determine values for refrigerants not included in this paragraph (e) upon request by a manufacturer.
(1) For HFC-134a, GWPREF = 1430;
(2) For HFC-152a, GWPREF = 124;
(3) For HFO-1234yf, GWPREF = 4;
(4) For CO2, GWPREF = 1. [77 FR 63165, Oct. 15, 2012]