Measurement of Passenger Compartment Refrigerant Concentrations Under System Refrigerant Leakage Conditions
|Publication Date:||1 September 2019|
This Standard is restricted to refrigeration circuits that provide air-conditioning for the passenger compartments of passenger and commercial vehicles.
This Standard includes analytical and physical test procedures to evaluate refrigerant concentration inside the passenger compartment. In the early phases of vehicle evaluation, usage of the analytical approach may be sufficient without performing physical tests.
The physical test procedure involves releasing refrigerant from an external source to a location adjacent to the evaporator core (inside the HVAC module). An apparatus is used to provide a repeatable, calibrated leak rate. If the system has multiple evaporators, leakage could be simulated at any of the evaporator locations.
This standard gives detail information on the techniques for measuring R-744 (CO2) and R-1234yf (HFO-1234yf), but the general techniques described here can be used for other refrigerants as well.
The purpose of this SAE Standard is to provide a uniform test procedure to evaluate the refrigerant concentration level inside of a vehicle passenger compartment resulting from leakage of refrigerant from a mobile air conditioning (MAC) system. This Standard does not establish concentration limits; however, legal limits may exist based on regulations or laws from local, national, or international authorities.
Refrigerant can leak from the evaporator, hoses, lines, and connectors that are directly exposed to the passenger compartment or the cabin air distribution system. Refrigerant concentration is influenced by leak rate, refrigerant charge, ambient temperature, recirculation door position, temperature door position, HVAC operation mode, blower speed, body sealing, vehicle speed, number of occupants in the vehicle, vehicle interior volume, and potentially other parameters specific to a vehicle design.