Absorption refrigerating systems must not be located less than 20 feet from a door window or ventilating air inlet to any building unless what condition is met?

The requirement that absorption refrigerating systems must not be located less than 20 feet from any door window or ventilating air inlet is primarily a safety measure. When an absorption refrigerating system contains a specific type of refrigerant that poses a greater risk, such as group 2 refrigerants in excess of 5 pounds, it becomes crucial to mitigate the potential hazards associated with refrigerant leaks or exposure.

Group 2 refrigerants are classified as higher toxicity refrigerants. If a system contains more than 5 pounds of such refrigerant, the threat to human health and safety increases. Hence, the 20 feet distance from windows, doors, or air inlets is established to reduce the likelihood of harmful refrigerant vapors entering the building in the event of a leak.

In circumstances where compliance with this distance is not feasible, ensuring that the system is appropriately monitored and controlled can allow for exceptions under strict regulations, which may include special containment measures or additional safety protocols. Therefore, the presence of a group 2 refrigerant in excess of 5 pounds triggers the need for more stringent safety precautions, highlighting the importance of proper refrigerant management in absorption refrigeration systems.