Updated November 2026 · Stratovac engineering
Start with the operating point
Every selection starts with the same five numbers: the gas, the flow, the inlet pressure, the outlet pressure (or the vacuum level) and the duty cycle. Add the site altitude and the inlet temperature if the gas is not air at sea level, and the hazardous-area class if the gas is flammable.
With those numbers, the choice of technology usually becomes obvious. The table below shows where each one fits.
| Technology | Typical flow | Typical pressure or vacuum | Strong points | Watch for |
|---|---|---|---|---|
| Regenerative (side channel) blower | About 30 to 2,300 CFM (50 to 3,900 m³/h) | Up to about 1 bar (14.5 psi) pressure or −0.7 bar (−10 psi) vacuum, multi-stage | Oil-free, no contact between moving parts, works as vacuum pump or compressor, simple to install, direct drive | Power rises quickly with pressure: always fit a relief valve and an inlet filter |
| Turbo (high-speed centrifugal) blower | Medium to very high flow | Low pressure, typically up to about 0.5 to 1 bar | Highest efficiency at low pressure, compact, speed control built in | Flow changes with system pressure; needs a stable operating point |
| Rotary lobe (positive displacement) blower | Medium to high flow | Up to about 1 bar pressure | Near-constant flow whatever the back pressure | Pulsation and noise, gearbox oil, more bearings, belts on many units |
| Claw compressor or claw vacuum pump | About 30 to 1,140 m³/h | Compressor up to about 2.2 bar; vacuum down to about 50 mbar abs | Dry running, higher pressure ratio than a blower, clean gas | Higher purchase cost than a regenerative blower |
| Oil-lubricated rotary vane vacuum pump | About 12 to 780 m³/h | Deep vacuum, down to about 0.1 mbar abs (29.9 inHg) | Deepest vacuum of the group, robust | Oil in contact with the gas; oil service needed |
Regenerative blower or turbo blower?
Choose a regenerative blower when the flow is low to medium, when you need vacuum or pressure from the same machine, or when the pressure goes above what a single turbo stage gives. It is the simple, rugged choice for aeration of small basins, pneumatic conveying, vacuum hold-down, drying, and biogas or gas recirculation.
Choose a turbo blower when the flow is high, the pressure is low and stable, and energy cost matters most, for example large aeration systems. A turbo blower moves more gas per kilowatt at low pressure, and its speed control follows the demand.
Rotary lobe or regenerative?
A rotary lobe blower keeps the flow nearly constant when the back pressure changes, which is why it is common on deep aeration tanks. A regenerative blower has no lobes, no gearbox oil and no belts, runs on fewer bearings and delivers a pulsation-free flow. On biogas, the regenerative design also avoids the shaft seals that lobe blowers need.
Size it for the real gas and site conditions
Blower curves are drawn for air at standard conditions. If your gas is lighter or heavier than air, or the site is at altitude, the pressure the blower makes changes with the gas density. A regenerative blower handling biogas with 60% methane, for example, makes less pressure than on air at the same speed, and needs less power.
Give the flow in standard units (SCFM or Nm³/h) with the gas composition, the altitude and the inlet temperature, and the selection is corrected for you. Our free selection assistant does this calculation and proposes a model and its accessories.
Do not forget the accessories
An inlet filter keeps dust out of the blower. A relief valve protects the motor when the line is blocked, which matters more on a regenerative blower than on any other type because its power rises with pressure. Add silencers where noise matters and a check valve when several blowers share a header.