Selecting the right screw air compressor is not about choosing the largest model, but about matching the machine to your actual air demand. An oversized compressor wastes energy and money; an undersized one leads to pressure drops, production downtime, and premature wear. This guide will walk you through three core parameters — air capacity (CFM / m³/min), working pressure (Bar / MPa), and motor power (kW) — to complete a scientific selection process, and recommend suitable models from the Huada SV+ series and LGGPM New A two-stage series.

Step 1: Calculate Total Air Demand (CFM / m³/min)

First, list all pneumatic equipment in your factory that will operate simultaneously, look up the rated air consumption of each device, sum them up, and then multiply by a simultaneous usage factor (typically between 0.6 and 0.85), since not all equipment will be running at full load at the same time.

Total Air Demand = Σ (Rated Air Consumption per Device) × Simultaneity Factor × 1.1 Safety Margin

Example: A workshop has 5 CNC machines, 3 grinders, and 2 sandblasting machines. The total nameplate air consumption is approximately 25 m³/min, but the actual simultaneous demand is approximately 16.5~23.4 m³/min.

Step 2: Determine Working Pressure (Bar / MPa)

Industrial screw air compressors commonly have rated discharge pressures of 0.7 MPa (approximately 7 bar), 0.8 MPa (approximately 8 bar), or 1.0 MPa (approximately 10 bar). Check the equipment in your factory with the highest pressure requirement, then add pressure losses from piping, filters, dryers, and other components (typically allowing a 0.1~0.2 MPa margin) to determine the required system pressure. For most general manufacturing applications, 0.7~0.8 MPa is sufficient; laser cutting, PET bottle blowing, and certain metal forming processes require 1.0 MPa or higher.

Step 3: Match Motor Power to Demand (kW)

Once the air demand and pressure are determined, the motor power (kW) is largely set. A practical rule of thumb: at 0.7~0.8 MPa discharge pressure, a 7.5 kW screw compressor produces approximately 1.2 m³/min, a 22 kW produces approximately 3.5 m³/min, and a 37 kW produces approximately 6.6 m³/min. For high energy-consuming equipment or applications with significant fluctuations in air demand, permanent magnet variable speed drive (PM VSD) compressors can save 25% to 35% of electricity compared to fixed-speed compressors.

Step 4: Recommended Huada Models

Based on the above selection logic, the following lists recommended models from Huada’s two main product lines across typical demand ranges. Both series feature permanent magnet variable frequency drive, quiet operation, direct-drive reliability, outstanding energy efficiency, and easy installation.

Huada SV+ Series — Permanent Magnet VSD Screw Air Compressor (Air-Cooled)

Best suited for: Small to medium workshops, machining shops, automotive repair, plastic injection molding, and general pneumatic applications. Air-cooling, direct drive, and compact dimensions make installation more convenient.

Huada LGGPM New A Two-Stage Series — Permanent Magnet Two-Stage VSD Screw Air Compressor (Air-Cooled)

Best suited for: High-capacity continuous production applications, such as textiles, lithium batteries, food and beverage, electronics and semiconductors, and other industries with high energy efficiency requirements.

Final Pre-Purchase Checklist

· Select based on actual simultaneously running air demand (not nameplate total)

· Confirm the maximum pressure required by your equipment

· Reserve a 10–15% safety margin for future expansion

· Choose PM VSD if your air demand varies across shifts

· Include dryers, filters, and air receivers in your system design

· Confim your site’s voltage,space,and piping layout

Not sure which model is right for your factory? Send your equipment list and air usage schedule to the Huada technical team. We provide free selection consultation and customized air compressor station system design services.