• Don’t leave the booth’s doors open when it’s not in use,
  especially overnight. The booth acts as a chimney when it
  cools, drawing air up through the ceiling filter – leaving dirt
  on the outlet side. Dislodged when the booth is started, the dirt
  becomes a contaminant that can temporarily remain in the booth’s
  turbulent air.
• Always run your booth for at least 30 minutes before you
  start to paint. This gives the booth time to eliminate small
  amounts of contaminated paint that may have lodged into the system.
• Unless you’re not going to use the booth for several hours,
  keep the fan running on the spray cycle once it’s turned on.
  This should maintain a positive booth pressure. Air will flow
  out as a vehicle is driven inside, helping to minimize any contamination
  carried in on the vehicle.
• Don’t change the ceiling filter just because it looks dirty.
  A ceiling filter of the best quality is designed to stop 10-micron
  particles, the smallest particles that start to cause damage to
  paint surfaces, from penetrating for up to two years under vibrating
  conditions. Particles that stain filters are less than 1 micron,
  so they won’t damage paint jobs if they fall from the filter.
  If you were to microscopically examine your visibly stained filter
  fibers, you’d find that they’re only partially covered with particles.

You should change your booth’s filter after two years or
1,500 working hours, depending on the quality of inlet air, if
the filter is physically damaged or when the pressure-drop through
the ceiling fan reaches the maximum the fan can handle. A manometer
can be used to show when this point is approaching.

• After changing the ceiling filters, run the booth for at
  least three to four hours while it’s empty before painting.
  This should eliminate most loose fiber/fiber parts, which are
  created when media is cut to fit. These fiber parts may still
  cause an occasional problem during the next few days, so keep
  in mind, the longer the purge cycle, the smaller the chance of
  problems.
• Check for small leaks around booth walls and lights, and
  seal them immediately. With the constant flexing caused by
  heating and cooling, the seals around corners, joints and under
  the lights can open up – usually indicated by jet marks of dust.
  Because wiping down walls – a good housekeeping habit – will remove
  the signs of leaks, inspect for leaks before cleaning the booth.
• Perform the least amount of prep work in your booth as
  possible. Use proper “tacky” rags for final wipe
  downs – never, for example, blow out crevices with compressed
  air while inside the booth. Using any other type of cloth will
  cause fibers to be released into the air. These particles, along
  with those blasted out of corners by compressed air, will float
  around in any turbulence and land in the worst possible places.
• Make sure paper used for masking is taped down well.
  Paper is one of the worst particle generators, especially if it’s
  flapping around in the air stream.
• Painters – or anyone entering the booth – should wear lint-
  and static-free coverings in good condition. Clothing worn
  in the booth should not be worn during other processes and should
  be kept in a locker near the booth’s entrance.
• Don’t store anything but operating essentials in your booth.
  Keeping dust-collecting or -creating items, such as empty paint
  drums and excess masking material, outside of your booth further
  ensures a contaminate-free paint job.