To determine when leaks must be repaired for comfort cooling equipment containing 50 lbs or more of refrigerant charge, we need to identify the annual leak rate threshold. According to regulations, the threshold at which leaks must be addressed is 10%.
Thus, when the annual leak rate reaches 10%, repairs must be made to ensure the equipment operates efficiently and complies with statutory requirements.
Therefore, the answer is:
[tex]\[
\boxed{10\%}
\][/tex]
