How much air flow does my Spray Paint Booth require?

OSHA 29.1910 and NFPA-33 have minimum requirements for air flow to decrease the concentration of flammable materials in a spray paint booth.  The old standard was 100 linear feet per minute (lfm), and this is still stated in the International Fire Code (IFC).  This air velocity is calculated with the spray paint booth empty and using a cross-sectional area of the air flow direction.  The more current codes require a minimum of 4 air exchanges per minute for wet or solvent-based paints.  Powdercoat booths are required to have 60 lfm.

Standard Tools uses 4 air exchanges to design our spray paint booths and uses the 100 lfm as a secondary reference.  This can be a difficult task as a spray paint booth with 100 lfm when empty may be 150 lfm when a large auto or other obstacle is in the paint booth.  This higher air flow can cause problems with the painting process.  An appropriate sized spray paint booth should be ordered to prevent this from being a problem; requesting the spray booth too small can lead to painting issues that are difficult to overcome.  Kelly can help you decide what size booth fits the needs of your body shop.

A concern of some new spray paint booth owners has been ‘my spray booth is a tornado’.  Air velocity of 100 lfm calculates to 1.1 miles per hour.  Comparing this to a normal walking pace of 3-4 miles per hour shows that no spray paint booth made by Tools USA is a tornado.  The perception of air velocity can be amplified by the sound of the fan(s) and the noise of air flowing through steel ductwork.

The real issue with air flow in a spray paint booth is having adequate air.  A 14’ wide x 9’ tall x 26’ long spray paint booth will exhaust at least 13,104 cubic feet of air per minute.  Running this spray booth for twenty minutes requires 262,080 cubic feet of available air.  This requires a building at least 17,472 sq ft with 15’ ceilings or 10,483 sq ft with 20’ ceilings.   This issue of an undersized building can be addressed with booth design and/or an air make-up unit.  Please contact Kelly at Standard Tools for more information.