What does ASHRAE Standard 15 require for each machinery room concerning refrigerant concentrations?

ASHRAE Standard 15 addresses the safety requirements for refrigeration systems and includes guidelines for managing refrigerant concentrations in machinery rooms. Specifically, it mandates that when the refrigerant concentration exceeds a particular threshold, necessary actions must be taken to ensure safety. One of the prescribed actions is to activate an alarm and implement mechanical ventilation in the machinery room.

Activating an alarm serves as a warning system for personnel, indicating that refrigerant levels may pose a risk. Mechanical ventilation is crucial in diluting and dispersing any potentially hazardous refrigerant that may accumulate, thus aiding in maintaining a safe environment. This twofold approach is essential for ensuring that the machinery room remains within safe operating parameters, thereby preventing hazardous conditions that can arise from high refrigerant levels.

The other options do not reflect the specific requirements set by ASHRAE Standard 15 regarding machinery rooms and refrigerant concentrations, as the standard is focused on early warning and mitigation through alarms and ventilation rather than isolation or evacuation measures.