Per general industry experience/standard:
- Water cooled condensers and their compressors (e.g. accommodation, etc.) are located in the engine room, safe area.
- Emergency air cooled condensers (e.g. serving temporary refuge, etc.) are located outdoor and rated Zone 1.
- Non-emergency air cooled condensers/compressors (e.g. HVAC units) are located outdoor and rated Zone 2.
It is more cost effective without compromising integrity or maintainability of the units based on past experience. Also creating separate rooms for external condensers requires provision of separate ventilation requirements for those rooms.