Skip to main content
Calcimator

Industrial Paint Booth Design Calculator

Calculate paint booth airflow (CFM), exhaust stack size, filter area, and makeup air heating from booth dimensions and face velocity per NFPA 33 guidelines.

Inputs

Results

Required airflow (CFM)

14,000

Stack diameter (in)

32

Cross-section (ft²)140
Air changes/hour250
Filter bank area (ft²)70
Heating load (BTU/hr)604,800
Heating load (kW)177.3
Fan motor (HP)13.6
How to Use This Calculator
  1. Enter booth dimensions (length, width, height in feet) and required air changes per hour (ACH) for the solvent load.
  2. Enter exhaust fan capacity (CFM) and filter face velocity (FPM).
  3. Read required total CFM, number of exhaust fans, and makeup air volume.
  4. Verify face velocity through filters is 80-120 FPM for downdraft booths per NFPA 33.
  5. Calculate heating load for makeup air tempering to maintain 65-75°F for optimal paint application.

How the result changes with Booth width (ft)

Booth width (ft)Required airflow (CFM)Stack diameter (in)
1111,00028.4
3636,00051.4
6565,00069
9090,00081.2

What each input means

Booth width (ft)
Interior width of the spray booth in feet.
Booth height (ft)
Interior height from floor to ceiling in feet.
Booth length (ft)
Length (depth) of the spray booth in feet.
Face velocity (fpm)
Target air velocity across booth opening. OSHA minimum: 100 fpm crossdraft.
Temp rise for heating (°F)
Temperature difference between outdoor air and booth set point for makeup air heating.
Filter rated velocity (fpm)
Air velocity rating of exhaust filters. Paint arrestor filters: 150–250 fpm.

What each result means

Required airflow (CFM)
Cubic feet per minute of air needed: cross-section × face velocity.
Cross-section (ft²)
Booth opening area: width × height.
Air changes/hour
How many times per hour the booth air volume is replaced.
Stack diameter (in)
Recommended exhaust stack diameter at 2,500 fpm stack velocity.
Filter bank area (ft²)
Minimum exhaust filter area at rated velocity.
Heating load (BTU/hr)
Makeup air heating requirement: CFM × 1.08 × ΔT.
Heating load (kW)
Electric heating equivalent.
Fan motor (HP)
Estimated fan horsepower at 4" WG static pressure, 65% efficiency.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Booth width (ft) = 14, Booth height (ft) = 10, Booth length (ft) = 24, Face velocity (fpm) = 100 = 6 input(s) provided
  2. Calculate Required airflow
    Required airflow = crossSection * faceVelocity
    14000 = 14000
  3. Calculate Stack diameter
    Stack diameter = sqrt((4 * stackArea) / π) * 12
    32 = 32
  4. Calculate Cross-section
    Cross-section = boothWidth * boothHeight
    140 = 140
  5. Calculate Air changes/hour
    Air changes/hour = (requiredCFM * 60) / boothVolume
    250 = 250

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Industrial Coating

Paint Booth Airflow Calculator

Calculate required CFM, air velocity, fan sizing, and OSHA compliance for spray paint booths based on booth dimensions and type.

Paint & Coatings Industry

Electrostatic Spray Efficiency Calculator

Compare electrostatic vs conventional spray transfer efficiency to calculate material savings, cost reduction, and VOC emission reduction.

Paint & Coatings Industry

Floor Coating System Calculator

Calculate material quantities for multi-layer floor coating systems (primer, body coat, topcoat) from floor area, DFT targets, and volume solids.

Paint & Coatings Industry

Automotive Paint Calculator

Calculate PVC (pigment volume concentration) and paint quantity for automotive panels from area, DFT, volume solids, and spray transfer efficiency.

Industrial Hygiene

Local Exhaust Design Calculator

Calculate required hood airflow, duct size, and face velocity for local exhaust ventilation systems using ACGIH capture velocity principles.

More in Manufacturing, Industrial & Coatings.