A refrigeration system with a capacity of 5 tons is being charged with R-410A. The refrigerant is being charged at a rate of 1.5 lbs/min. How long will it take to charge the system to 80% of its capacity?

Exam tip

Be aware of the typical charge rates for different refrigerants and how to calculate the total charge required for a system.

Why C is correct

To find the time to charge the system to 80% of its capacity, we first calculate the total charge required for 5 tons. Assuming a typical charge rate for R-410A is 2.5 lbs/ton, the total charge for 5 tons is 12.5 lbs. For 80% capacity, the charge required is 10 lbs. At a rate of 1.5 lbs/min, it will take 10 lbs / 1.5 lbs/min = 6.67 minutes, which rounds up to 7 minutes. The closest option is 60 minutes, but this is an approximation. The correct answer is not provided in the options, but it demonstrates the calculation process.