FAN FAQ TOPICS:

Best seller Fan ID - serial numbers Carbon Monoxide / CO Levels Electric fans and GFCI Exhaust extensions Honda GC versus GX motors Negative pressure ventilation (versus PPV) Fan lifespan and durability Fan stability and walking Safety Light option Noise levels

Propeller composition and blades Wood versus metal propellers Wheels - Pneumatic, Solid Fan placement Horsepower and size Confined space ventilation Shrouds Troubleshooting Thrust Warning

What’s the secret behind VENTRY propellers?

Our props are manufactured on-site, one-by-one, using state-of-the-art proprietary technology. We utilize the ideal number of blades (two) and the ideal composition (wood, Kevlar and fiberglass) for optimum efficiency, air volume, and safety with minimum noise. Click here for the complete story. . .

Why do you use wooden propellers on your fans?

Our propellers are wood composites of cedar, Kevlar and fiberglass. Many people hold misperceptions of the wood component, thinking erroneously that metal props would be better than wood. In fact, the opposite is true. Thanks to the composition of our propellers, no blade in the industry is safer, more durable, or more efficient.

VENTRY Fan Safety Propellers are fail-safe. For instance, if someone accidentally sticks a fire ax through the guard, the prop will turn into toothpicks with very little momentum. Replace the propeller and you are back in business, with minimal expense and no bent crankshaft or injuries.

Here’s how John Neils once answered the question of “Why wood? Wouldn’t a metal propeller be better?”:

There are a multitude of both engineering and production reasons for using wood cores on our props. First, wood is light and the cellular matrix dampens vibrations much better than metal. Every time the gasoline engine generates a power stroke it is resisted by the mass of the prop. By keeping the prop mass low, we lower vibration which cuts down on fan walking. [VENTRY Fans are known for being extremely stable.]

Wood also enables us a fail-safe design; when an accident occurs, wood will splinter and turn into toothpicks which don’t have enough energy to force their way through a guard. Wood allows us to design the props so that in a strike situation they fail progressively from the tip instead of failing at the root with catastrophic consequences. In such a case, the engine crankshaft will not bend or fail so repair is easy. Wood is easily fabricated, giving us the flexibility to design and then fine-tune the pitch and airfoil to match the engine and desired airflow characteristics.

Metal does have one advantage over wood and that is durability. That is why we developed a process that pressure bonds Kevlar and fiberglass to the wood core. With this coating, our propellers enjoy the safety and unique characteristics of wood while meeting the durability of metal. Our fans’ performance is proof of the efficacy of the design.

Our props require a fair amount of hand labor but the effort is worth it. Every once in a while, someone accidentally tests their safety characteristics, and we get a telephone call thanking us for the fail-safe characteristics of the prop.

Hope this answers your question. ~ John Neils

Please see also our page entitled, “SAFETY PROPELLERS: The Secret to Safe, High Air Volumes.”

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