§ 86.166-12Method for calculating emissions due to air conditioning leakage.
This section describes procedures used to determine a refrigerant leakage rate in grams per year from vehicle-based air conditioning units. The results of this test are used to determine air conditioning leakage credits according to § 86.1866-12(b).
(a)Emission totals. Calculate an annual rate of refrigerant leakage from an air conditioning system using the following equation:
Grams/YRSP = The emission rate for service ports and refrigerant control devices, in grams per year.
HSSP = The number of high side service ports.
LSSP = The number of low side service ports.
STV = The total number of switches, transducers, and pressure relief valves.
TXV = The number of refrigerant control devices.
(d)Flexible hoses. Determine the permeation emission rate in grams per year for each segment of flexible hose using the following equation, and then sum the values for all hoses in the system to calculate a total flexible hose emission rate for the system. Hose end connections shall be included in the calculations in paragraph (b) of this section.
Grams/YRFH = 0.00522 × (3.14159 × ID × L × ER)
Grams/YRFH = Emission rate for a segment of flexible hose in grams per year.
ID = Inner diameter of hose, in millimeters.
L = Length of hose, in millimeters.
ER = Emission rate per unit internal surface area of the hose, in g/mm2. Select the appropriate value for ER from the following table:
All rubber hose
Standard barrier or veneer hose
Ultra-low permeation barrier or veneer hose
(e)Heat exchangers, mufflers, receiver/driers, and accumulators. Use an emission rate of 0.261 grams per year as a combined value for all heat exchangers, mufflers, receiver/driers, and accumulators (Grams/YRMC).
(f)Compressors. Determine the emission rate for compressors using the following equation, except that the final term in the equation (“1500/SSL”) is not applicable to electric (or semi-hermetic) compressors:
Grams/YRC = The emission rate for the compressors in the air conditioning system, in grams per year.
OHS = The number of O-ring housing seals.
MHS = The number of molded housing seals.
FAP = The number of fitting adapter plates.
GHS = The number of gasket housing seals.
SSL = The number of lips on shaft seal (for belt-driven compressors only).
(g)Definitions. The following definitions apply to this section:
(1)All rubber hose means a Type A or Type B hose as defined by SAE J2064 with a permeation rate not greater than 15 kg/m2/year when tested according to SAE J2064. SAE J2064 is incorporated by reference; see § 86.1.
(2)Standard barrier or veneer hose means a Type C, D, E, or F hose as defined by SAE J2064 with a permeation rate not greater than 5 kg/m2/year when tested according to SAE J2064. SAE J2064 is incorporated by reference; see § 86.1.
(3)Ultra-low permeation barrier or veneer hose means a hose with a permeation rate not greater than 1.5 kg/m2/year when tested according to SAE J2064. SAE J2064 is incorporated by reference; see § 86.1.