How is leak rate typically expressed?

The leak rate is typically expressed as a percentage of the appliance's full charge because this method allows for a clear understanding of the extent of refrigerant loss relative to the total capacity of the system. By using a percentage, technicians can assess whether the leak is significant enough to warrant repairs or if it is within acceptable limits, which helps in monitoring compliance with environmental regulations and maintaining system efficiency.

In contrast, expressing the leak rate in terms of gallons per hour or cubic feet per minute does not provide a direct comparison to the system's total refrigerant capacity and may not accurately reflect the impact of the leak on system performance. Additionally, stating a leak rate as a fixed dollar amount per year does not give an immediate understanding of the physical loss of refrigerant, which is crucial for assessing the system's operational integrity.