EPA Type 2 Practice Test

Charging a high‑pressure appliance by weight means using a calibrated scale to measure exactly how much refrigerant you add, and then following the system manufacturer’s specified charge. This approach is precise because the total refrigerant mass in the system determines proper lubrication, heat transfer, and performance, regardless of cylinder temperature or vapor content. Weighing the refrigerant you add (and accounting for what’s already in the system) gives an accurate final charge. Relying on feel or experience is subjective and unreliable, and charging to a target pressure on a gauge can mislead you because pressure reflects temperature and operating state, not the actual refrigerant mass. A fixed amount per ton ignores differences between systems and refrigerants and can easily over- or undercharge. Following the manufacturer’s weight-based requirement ensures the correct, safe charge.