The following metrics are hard digital standards for industry acceptance and equipment selection, directly determining the compliance, painting performance, and service life of automotive paint booths. They can be directly used for procurement acceptance and equipment rating.

I. Material Quality (Digital Metrics)

1. Booth Panels: External wall ≥0.426mm color-coated steel sheet; internal wall ≥0.376mm galvanized steel sheet; rock wool insulation density ≥120kg/m³, thickness ≥50mm.

2. Steel Structure Frame: Square tube wall thickness ≥2.0mm; galvanized coating thickness ≥85μm; anti-rust and anti-corrosion service life ≥8 years.

3. Floor Grating: Galvanized steel grating thickness ≥3.0mm; load capacity ≥300kg/m²; anti-slip coefficient ≥0.6.

II. Air Supply Room (Fan Room) Core Metrics

1. Fan Configuration: Supply fan power ≥5.5kW/unit; exhaust fan power ≥5.5kW/unit; airflow rate ≥25,000m³/h/unit.

2. Air Pressure: Static pressure ≥300Pa; dynamic pressure ≤50Pa; fan noise ≤75dB(A).

3. Motor Protection: IP55 or higher; insulation class F; continuous operation duration ≥8 hours.

III. Air Inlet Path Metrics

1. Filtration System: Primary filter efficiency ≥G4 (≥80%); ceiling filter efficiency ≥F5 (≥95%); HEPA filter ≥F6.

2. Inlet Air Velocity: Spray painting mode: 0.3–0.5 m/s; baking mode: 0.2–0.4 m/s.

3. Air Change Rate: Spray painting ≥260 times/h; baking ≥180 times/h.

IV. Exhaust Path Metrics

1. Emission Concentration: Non-methane total hydrocarbons ≤60mg/m³; particulate matter ≤10mg/m³ (compliant with GB 24433-2023).

2. Activated Carbon Adsorption System: Iodine adsorption value ≥800mg/g; filling volume ≥100kg/unit.

3. Regenerative Catalytic Oxidizer (RCO): Light-off temperature 250–300°C; purification efficiency ≥95%.

V. Paint Mist Control Metrics

1. Paint Mist Capture Rate: Dry filtration ≥98%; wet Venturi ≥99%.

2. Residual Overspray: Suspended paint mist inside booth ≤2mg/m³; surface particles on workpiece ≤3 particles/m².

3. Airflow Pattern: Vertical laminar flow rate ≥90%; no vortex dead zones.

VI. Temperature Rise Speed Metrics

1. Heating Rate: 20°C → 60°C ≤25 minutes; 20°C → 80°C ≤30 minutes (for northern regions; southern regions approx. 10 minutes less).

2. Temperature Uniformity: Temperature difference inside booth ≤±2°C; top-to-bottom temperature difference ≤3°C.

3. Thermal Efficiency: Fuel-fired type ≥85%; electric heating ≥98%.

VII. Exhaust Duct Metrics

1. Duct Material: Galvanized spiral duct wall thickness ≥1.2mm; stainless steel duct wall thickness ≥1.0mm.

2. Exhaust Air Velocity: Main duct ≥12 m/s; branch ducts ≥8 m/s.

3. Sealing Performance: Air leakage rate ≤3%; duct negative pressure ≥200Pa.

VIII. Operational Safety Metrics

1. Explosion Protection Rating: Electrical components Ex d IIB T4; booth explosion protection level ≥Ex II 2GD.

2. Safety Devices: Overtemperature alarm ≤70°C; emergency stop response time ≤0.5s.

3. Fire Suppression System: Sprinkler activation temperature ≤68°C; fire suppression response time ≤3s; combustible gas alarm concentration ≤25% LEL (Lower Explosive Limit).