There is no single number that fits every data centre. But there are guidelines and sensible intervals per zone. Here is how to arrive at a defensible schedule.
Different zones, different intervals
A good schedule treats surfaces, equipment, high work and the subfloor separately. Each has its own rhythm:
- Floor surface and access zones: most often, commonly quarterly or more frequent.
- Subfloor / plenum: less often but critical, guidance recommends at least annually.
- Equipment-adjacent surfaces and high work: on interval and around installs.
What the guidance says
ASHRAE recommends cleaning data centres at least annually, with higher frequencies where conditions demand. NFPA 75, focused on fire safety, recommends regular removal of combustible dust, in practice often quarterly.
The factors that set it
Particle levels, traffic, construction or install activity, airflow design and equipment sensitivity together set the right interval. Construction and migrations call for extra cleaning for a time.
Start from a measurement
The most reliable basis is a survey plus a particle measurement: it turns “it depends” into a justified interval, tuned to your specific room.
Key takeaways
- No universal number: zones have their own rhythm.
- ASHRAE: at least annually; subfloor annually.
- NFPA 75: regularly remove combustible dust.
- Set the interval from a measurement.