Chiller Safety Issues
Large chillers are most commonly located in mechanical equipment rooms within the building they are air conditioning. If a hazardous refrigerant is used (like ammonia), the equipment room must meet additional requirements typically including minimum ventilation airflows and vapor concentration monitoring.
In many urban code jurisdictions, the use of ammonia as a refrigerant is prohibited outright. For large chillers, the refrigerant charge is too large to allow hydrocarbon refrigerants in chillers located in a mechanical equipment room.