Air Requirements & Compressor Sizing for Blasting

2. Matching Pressure & Flow

• Operating Pressure – Standard site compressors operate at 7–10 bar, but sand/grit blasting and drilling may require up to 12–14 bar. Verify your blasting machine’s pressure requirement and ensure your portable air compressor or diesel compressor can supply both the required pressure and flow simultaneously.

• Air Consumption by Machine Type –

  • Dry Ice Cleaning Machines – Typically need 10–50 CFM at 6–8 bar depending on the nozzle and pellet feed rate. Smaller systems like entry-level CO₂ cleaners can run comfortably on a 50 CFM portable air compressor, while professional systems often use a diesel compressor for continuous work.

  • Dry Ice Blasting Machines – Require a higher and steadier air supply, usually 50 CFM and above at 8–10 bar. Larger units can need 80–150 CFM, best paired with a 100–200 CFM diesel compressor.

  • Sand/Grit Blasting Machines – Depending on nozzle size, expect 50–250 CFM at 8–12 bar. The more CFM you have, the bigger the nozzle and the quicker the job. These setups nearly always run on a road-tow diesel compressor rated at 175 CFM +.

  • Vapour & Dustless Blasting Machines – Combine water with abrasive, so airflow must stay high to maintain atomisation. Allow 90 CFM and upwards at 8 bar. A 120–175 CFM diesel compressor is ideal for reliable, dust-controlled performance.

  • Soda Blasting Machines – Usually run between 40–120 CFM at 6–10 bar, depending on nozzle size and soda feed rate. Mid-range setups operate well with a 100 CFM portable air compressor, though commercial rigs benefit from larger diesel compressors to sustain flow and pressure.

3. Filtration & Moisture Control

• Cyclone Separators & Aftercoolers – Dry air is crucial for blasting. Look for a portable air compressor or diesel compressor with built‑in water separators and aftercoolers to reduce discharge temperature and remove condensate. Moisture in the air stream can freeze or clog media.

• Fine Filtration – Fine filters remove oil aerosols and contaminants. Clean, oil‑free air from your portable air compressor or diesel compressor prevents media contamination and ensures a consistent finish.

4. Duty Cycle, Cooling & Fuel Efficiency

• Continuous Duty – Blasting is a high‑demand application. Make sure your portable air compressor or diesel compressor is designed for 100 % duty cycles, with adequate cooling for both the engine and aftercooler.

• Fuel Consumption – The fuel efficiency of your diesel compressor directly affects operating costs. Engines with good part‑load efficiency can save thousands over the machine’s lifecycle, so compare specific fuel consumption figures.

• Emissions Compliance – Stage V engines are mandatory on most UK and EU construction sites. If your job site requires compliance, select a Stage V–compliant diesel compressor. Some portable air compressor models are also available with advanced after‑treatment systems.

5. Practical Sizing Steps

1. Identify Your Blasting Machine’s Air Demand – Check the machine’s manual or ask your supplier for CFM and pressure requirements at your target nozzle size, then choose a portable air compressor or diesel compressor that meets or exceeds that demand.

2. Add Safety Margin – Select a portable air compressor or diesel compressor with around 10–20 % more FAD than the calculated requirement to account for hose losses, wear and environmental factors.

3. Consider Future Needs – If you plan to upgrade to larger nozzles or run multiple tools, invest in a higher‑capacity diesel compressor or portable air compressor from the outset.

4. Check Portability & Compliance – For road‑tow units, ensure the chassis meets UK regulations, including brakes and lighting. Site‑tow variants may be lighter but can only be moved internally. Decide whether you need a fully road‑legal portable air compressor or a site‑tow diesel compressor.