Rotary Lobe PD Blowers

​RootsTM is the most famous brand name in the field of positive displacement (PD) blowers.

Since we invented the Twin Lobe Blower, so synonymous has the name of Roots become, that it is common to refer to these PD blowers as 'Roots Blowers'. However, the only true Roots Blowers are those that are supplied by Howden.

PD Blowers work by drawing in air through an inlet and then against the system pressure forcing that trapped air out the outlet side. They are perfect for delivering reliably constant pressures, and the flow can be altered based on the operating speed.

All Howden Roots blowers are of a compact, sturdy design engineered for continuous duty and maximum reliability. These blowers have a time tested lubrication system and an exclusive “figure-8” gearbox design improves oil distribution to the timing gears and lengthens bearing life.

Incorporating our innovative Whispair technology for low noise, low pulsation compression, Howden continues to lead the way when designing and maufacturing PD Blowers.

Roots RAM Series

The Roots PD Blower - learn more about what it can do

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Howden Roots PD Blowers are used in many industries especially waste water treatment, industrial processing applications and mechanical vapour compression

Manufactured using Whispair or DVJ/DPJ principles

Backflow can be reduced and controlled within the units

Operation does not require lubrication within the lobe cavity


Wide range of sizes and specifications

Vertical or horizontal installation options

Cost effective design


Case Studies

Bird Island

Bird Island Wastewater Case Study

In 2011, Howden began operating the largest-ever installation of its Roots IntelliView controls system at Bird Island’s aeration basins.

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PD Calcs

Positive Displacement (PD) Blower Calculator

Selecting the correct blower is the most important decision when designing a pneumatic conveying system. Our document helps you get it right.

Read case study

If you would like to submit an enquiry please get in touch.