Ignition sources for flammable A2L refrigerant in air
For maintenance and repair work on refrigeration systems, equipment and tools have to be evaluated, whether they are possible ignition sources. The AHRI Report 8017 concludes on several possible sources, based on extensive tests, that many sparking parts can be excluded.
The sparks of standard tools, hot surfaces and electric tools can thus, to a large extend, be considered no ignition source, as shown in the table below for mildly flammable A2L compared to non flammable A1. The term “routine” means, that no special tool is necessary.
Part/tool | A1 | A2L |
|---|---|---|
Manometer bridge | routine | routine |
Charging hose | routine | routine |
Torque wrench | routine | routine |
Brazing torch | routine | routine |
Tube cutter | routine | routine |
Tube bending tool | routine | routine |
Extra fan | routine | routine |
Scales | routine | routine |
Vacuum pump | routine | Switch outside zone |
Powder/CO2 extinguisher | routine | A2L certified |
Gas detector | routine | A2L certified |
Electronic leak detector | routine | A2L certified |
Refrigerant recovery cylinder | routine | Left hand thread |
Refrigerant recovery machine | routine | A2L certified |
Fan
The fan is usually placed to blow fresh air into the machine room, so that possibly leaking refrigerant can not accumulate and form flammable areas on the floor. The room shall always be ventilated, as all refrigerants can suffocate.
Gas detector
The portable gas detector is a personal protection device. In case there is no gas warning system for the flammable refrigerant, or it is shut off because of a defect, the portable gas detector can warn the worker during the maintenance or repair.
Most A2L refrigerant blends of the R400 series contain a significant amount R1234yf and R32. These or one of these could be sensed by the gas warning system or a general sensor for combustible gas might be used, calibrated for those components.
Electronic leak detector, Refrigerant recovery cylinder and recovery machine
The electronic leak detector, the recovery machine and the recovery cylinder have to be suitable for the flammable refrigerant gas.