Safety, Fuel Gas Piping, and Environmental Refrigerant Handling
This domain tests jobsite safety, fuel-gas piping, combustion air, and refrigerant handling. Expect code-based questions on gas piping, venting, leak testing, and EPA refrigerant rules.
Fuel gas and combustion air
Fuel-gas piping follows NFPA 54/ANSI Z223.1 as adopted in New Jersey. Provide a sediment trap, shutoff valve, proper support, and bonding for CSST. Size pipe for the appliance input and allowable pressure drop. Leak-test with air or inert gas, not flame. Combustion air: unconfined spaces need about 50 ft³ per 1,000 Btu/h input.
Worked example
A 100,000 Btu/h furnace in a basement 20 ft × 25 ft × 8 ft = 4,000 ft³. Required volume = 100 × 50 = 5,000 ft³. The space is confined; provide outdoor combustion air by the code's opening method or direct-vent the appliance.
Refrigerants
EPA Section 608 certification is required to buy and handle regulated refrigerants. Do not vent; recover, recycle, or reclaim. Fill cylinders to no more than 80% by weight, use proper recovery cylinders, and avoid mixing refrigerants. A2L refrigerants are mildly flammable; control ignition sources and follow the manufacturer's charge and ventilation limits.
What costs marks
- Flame-testing gas piping.
- Omitting CSST bonding or a sediment trap.
- Failing to provide combustion air in a tight basement.
- Overfilling refrigerant cylinders.
- Treating A2L refrigerants like A1 refrigerants.