SAFETY PROPELLERS Efficient, Small Size, and High CFM The secret to the high air volume of VENTRY® Fans lies in our unique, fail-safe Safety Propellers.

See also: Prop FAQ page Click here for testimonials

Our dual-blade props are engineered and manufactured using the fundamentals of aerodynamics and state-of-the-art proprietary technology. We engineer each propeller specifically for each motor, in order to utilize every bit of horsepower and maximize the power curve for highest air volume.

Highly efficient VENTRY Fans are frequently tested against higher hp competitors, and are chosen again and again after revealing higher hp to be unnecessary. Thanks to Safety Propellers, they are known to move more air with smaller motors.

An obvious and huge benefit of propeller efficiency is a great reduction in noise (see further down this page) and carbon monoxide. Moving more air with less horsepower also saves you much bulk and weight and expense.

<-- At left, a simple animation of one step in the propeller design process. Propeller “blanks” like this eventually become the template for propellers on various fans. This particular propeller was engineered for the new 20-inch 4.8 hp fan. Only 20-inches long, it still moves 17,300 cfm!

Placement of Fan Farther Back

The advanced curvature of the prop -- forward sweeping tips -- makes for a tighter, more uniform air cone. This high-quality and consistent air cone (as opposed to erratic) helps with aiming and allows the fan to be placed farther away from the target. The narrow air cone pushes air directly at the target instead of around it in a wide circle. Click here for illustrations and explanations of the airstream in action.

Placement farther back from the target is crucial for keeping the fan out of your way. You should never have to crawl over the top of a fan while you are using it!

Less Blades equal Less Noise

Do not fall for the “more is better” fallacy of multiple-blade props. Multiple blades stir the air rather than push it, wasting energy in the form of noise. This is called “form drag” or “eddy making drag” and is due to multiple tips and greater surface area.

TRUE STORY: We once had a fire department call us and complain that their VENTRY Fan was not working very well. Why did they think that? The VENTRY Fan was not making “enough” noise! They just assumed that to be effective, fans also had to be painfully loud. Nope.

Note: VENTRY Fans are quiet for other reasons too. Please also see the Guards page and the Solved/Quiet page.

Safety and Stability, Thanks to their Composition

VENTRY Safety Props are Kevlar and fiberglass composites with a wooden core manufactured at our facility. The wooden core makes Safety Propellers naturally vibration dampening which is one of several reasons VENTRY Fans are known to stay put and not walk!

The bigger advantage of our propellers’ composition is that, as Kevlar-fiberglass-cedar composites, they are accepting of a tremendous amount of use and abuse, yet designed for controlled disintegration when safety warrants, without the release of high energy projectiles or shrapnel.

When $#!+ hits the fan, it better be a VENTRY!	As the broken prop we bring to tradeshows illustrates, if something goes very wrong (and it sometimes does!), VENTRY Fans are fail-safe! A pike pole was shoved through the guard, hitting the propeller at left. As it is designed to do, the affected areas of the propeller disintegrate into low-energy toothpicks. No shrapnel. No expensive engine damage. No firefighter injuries! We have had numerous calls from startled but safe firefighters thanking us for the fail-safe design of VENTRY Fan propellers. See more on prop safety on our FAQ page.
See also: Can I use a VENTRY propeller on my existing fan?
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