The compressor room is an afterthought on most facility projects. It gets whatever space is left over, wherever is convenient, fitted out to minimum specification. This is a mistake that tends to compound over time.
I've been involved in enough installations — and spent enough time troubleshooting problems in poorly designed rooms — to have strong views on what makes a compressor installation work well.
Location
The compressor room should be positioned to minimise the length of the distribution system between it and the heaviest air users. Every metre of pipework is a pressure drop, and long runs on small-bore pipe are a common source of underperformance.
Keep the room away from sources of contamination. A compressor drawing in air from near a spray booth will contaminate the oil rapidly and struggle to meet air quality requirements. A compressor near a bakery or other starchy environment will clog its inlet filter within weeks. Locate the inlet carefully.
Avoid rooms that see extreme temperatures. Compressors need cool, clean air. A room that reaches 40°C in summer due to poor ventilation will increase compressor discharge temperature, shorten oil life, reduce performance and eventually cause thermal protection trips.
Ventilation
This is where most compressor installations fall short. An air-cooled compressor discharges a large volume of hot air that must leave the room. Inadequate ventilation recirculates this hot air, raising room temperature and reducing compressor efficiency.
The rule of thumb: the cooling air volume specified by the manufacturer needs a clear path in and a clear path out. In and out should not be adjacent — hot exhaust air must not be allowed to short-circuit back to the inlet.
If the room layout makes natural ventilation inadequate, fit powered extraction. The cost of a properly sized extraction fan (typically £800-2,500 installed) is trivial compared to the running cost penalty of a compressor operating in a hot room.
Duct the hot exhaust air out of the room (and ideally to somewhere useful — see my post on heat recovery) rather than letting it sit in the space.
Clearances
Manufacturers specify minimum clearances around their equipment for a reason: maintenance access. An engineer who can't get to the oil fill point, filter housings, or separator bowl without moving other equipment will do a less thorough job and take longer.
Leave at least 1m clear on the service side of every compressor. Leave enough clearance above to use a hoist if your equipment is heavy enough to require one. If you're fitting multiple machines, think about the sequence in which they'll need service and make sure you can access one without isolating the others.
Noise
Compressor noise is a real issue for sites with offices or welfare facilities nearby. For new installations, consider the noise specification early — quieter machines cost more but that cost is often less than acoustic treatment fitted after the event.
Acoustic enclosures work well but reduce access. If you're fitting an enclosure, make sure the maintenance procedures can be completed with the enclosure closed or that opening it is genuinely practical.
Floors and Drainage
Concrete floors with a slight fall to a drain point. The drain needs to be accessible and plumbed to an oil/water separator — the condensate from a compressed air system contains oil and cannot go to sewer without treatment. This is a legal requirement in the UK under environmental regulations.
A dry, clean floor makes it easier to spot leaks. An oil-stained floor where everything looks wet makes early detection of problems much harder. Keep the room clean.