View all text of Subpart B [§ 86.101 - § 86.166-12]
§ 86.165-12 - Air conditioning idle test procedure.
(a) Applicability. This section describes procedures for determining air conditioning-related CO
(b) Overview. The test consists of a brief period to stabilize the vehicle at idle, followed by a ten-minute period at idle when CO
(c) Test cell ambient conditions. (1) Ambient humidity within the test cell during all phases of the test sequence shall be controlled to an average of 40-60 grains of water/pound of dry air.
(2) Ambient air temperature within the test cell during all phases of the test sequence shall be controlled to 73-80 °F on average and 75 ±5 °F as an instantaneous measurement. Air temperature shall be recorded continuously at intervals of not more than 30 seconds.
(d) Test sequence. (1) Connect the vehicle exhaust system to the raw sampling location or dilution stage according to the provisions of this subpart. For dilution systems, dilute the exhaust as described in this subpart. Continuous sampling systems must meet the specifications provided in this subpart.
(2) Test the vehicle in a fully warmed-up condition. If the vehicle has soaked for two hours or less since the last exhaust test element, preconditioning may consist of a 505 Cycle, 866 Cycle, US06, or SC03, as these terms are defined in § 86.1803-01, or a highway fuel economy test procedure, as defined in § 600.002-08 of this chapter. For soak periods longer than two hours, precondition the vehicle using one full Urban Dynamometer Driving Schedule. Ensure that the vehicle has stabilized at test cell ambient conditions such that the vehicle interior temperature is not substantially different from the external test cell temperature. Windows may be opened during preconditioning to achieve this stabilization.
(3) Immediately after the preconditioning, turn off any cooling fans, if present, close the vehicle's hood, fully close all the vehicle's windows, ensure that all the vehicle's air conditioning systems are set to full off, start the CO
(4) Measure and record the continuous CO
(5) Within 60 seconds after completing the measurement described in paragraph (d)(4) of this section, turn on the vehicle's air conditioning system. Set automatic air conditioning systems to a temperature 9 °F (5 °C) below the ambient temperature of the test cell. Set manual air conditioning systems to maximum cooling with recirculation turned off, except that recirculation shall be enabled if the air conditioning system automatically defaults to a recirculation mode when set to maximum cooling. Continue idling the vehicle while measuring and recording the continuous CO
(6) This paragraph (d)(6) applies only to manually controlled air conditioning systems. Within 60 seconds after completing the measurement described in paragraph (d)(5) of this section, leave the vehicle's air conditioning system on and set as described in paragraph (d)(5) of this section but set the fan speed to the lowest setting that continues to provide air flow. Recirculation shall be turned off except that if the system defaults to a recirculation mode when set to maximum cooling and maintains recirculation with the low fan speed, then recirculation shall continue to be enabled. After the fan speed has been set, continue idling the vehicle while measuring and recording the continuous CO
(e) Calculations. (1) For the measurement with no air conditioning operation, calculate the CO
(2)(i) For the measurement with air conditioning in operation for automatic air conditioning systems, calculate the CO
(ii) For the measurement with air conditioning in operation for manually controlled air conditioning systems, calculate the CO
(3) Calculate the increased CO
(f) The Administrator may prescribe procedures other than those in this section for air conditioning systems and/or vehicles that may not be susceptible to satisfactory testing by the procedures and methods in this section. For example, the Administrator may prescribe alternative air conditioning system settings for systems with controls that are not able to meet the requirements in this section.