When the annual leak rate exceeds which percentage must all comfort cooling systems with more than 50 lb of refrigerant be repaired?

• A. 5%
• B. 8%
• C. 10%
• D. 15%

Answer: (C)

The rule tests how much refrigerant a larger comfort cooling system is losing in a year. For systems with more than 50 pounds of refrigerant, if the annual leak rate goes above 10 percent, every leak must be repaired. The leak rate is found by dividing the amount that leaks in a year by the total refrigerant in the system, then multiplying by 100. So, for a 60-pound system, leaking 6 pounds in a year is exactly 10% and not required to be repaired under this rule; leaking more than 6 pounds (over 10%) means repair is required.