Twin Lobe vs Tri Lobe vs Side Channel Blowers: How to Choose

Short answer: choose a twin lobe roots blower for most STP/ETP aeration and pneumatic conveying, a tri lobe blower when lower pulsation and noise matter, and a side channel blower for low-pressure aeration, vacuum and aquaculture duties.

Twin lobe roots blowers

Two figure-eight rotors turn in opposite directions and push trapped pockets of air from inlet to outlet without internal compression. They deliver an almost constant air flow regardless of pressure changes, which suits diffused aeration in sewage and effluent treatment, filter backwash and pneumatic conveying. Everest twin lobe blowers.

Tri lobe roots blowers

Each rotor has three lobes, so air is delivered in smaller, more frequent pulses. The result is smoother flow, lower pressure pulsation and lower noise — useful near occupied buildings and for long air headers. Everest tri lobe blowers.

Side channel (regenerative) blowers

An impeller with many blades accelerates air repeatedly through a side channel. They are compact, nearly maintenance-free and work at lower pressures, so they suit vacuum handling, aquaculture, small aeration tanks, drying and air knives. Everest side channel blowers.

Quick comparison

Type	Pressure capability	Noise and pulsation	Typical uses
Twin lobe	Medium	Higher; usually needs silencers or a hood	STP/ETP aeration, conveying, backwash
Tri lobe	Medium	Lower than twin lobe	Aeration and process air near people
Side channel	Low	Low	Vacuum, aquaculture, small aeration

What we need to size your blower

1. Air flow in m³/h or CFM.
2. Discharge pressure — for aeration, the water depth over the diffusers plus losses.
3. Duty hours and standby philosophy.
4. Power supply and whether a VFD is needed.
5. Indoor or outdoor installation and noise limits.

For very small plants, Fujimac diaphragm air pumps can replace a blower.