Koenders Free Air Windmills

Field tested and proven successful for over 25 years.

A proven low-maintenance, low cost, highly effective method of maintaining water quality!

Buy with confidence, knowing that Koenders Windmills time-tested design features increase reliability, performance and safety.

Windmill Design Features:

  • Crankshaft & Bearings
    1″ Turned, ground and polished steel crankshaft. Long lasting, heavy duty, durable sealed bearings.

  • Streamlined, Large-Surface Blades
    Engineered for most efficient operation in low and high wind speeds.

  • Durable and Efficient Diaphragm
    Allows windmill to save energy but still produce maximum air volume and maximum longevity.

  • 1/2″ Piston Stroke
    Engineered for most efficient air production and maximum diaphragm life.

  • Large Tail
    The large surfaced tail area provides maximum control in all wind speeds and ensures efficient overall operation.

  • Strong Tail Arms
    Tail arm rigidity further ensures windmill control.

  • Top Mounted Compressor
    Top mounting and connected through a rigid pivot tube, provides smooth operation and mechanical longevity. Compressor top air valve assembly makes for very easy maintenance.

  • Pivot Tube
    Re-engineered to eliminate ice build up.

  • Tower Design (12′ – 16′ – 20′ – 24′ Heights)
    The strong, cross brace reinforcement design gives added strenght to any tower height. This design also discourages climbing of the tower.

The Koenders Windmill can be located up to approximately 1000′ from the water source.

Windmill Specifications
Capacity Up to 1.5 CFM (cubic feet of air per min.)
Turbine Type Upwind
Rotor Diameter 65"
Swept Area 23.05 sq. ft.
Blade Design Proprietary
Transmission Direct drive
Stroke 0.5"
Overspeed Protection Automatic
Foundation 3 ground rods; 1" diameter pipe, 4′ long


Shipping Information
Product # of pcs Description Weight (lbs.) Dimension
H W D
12′ KFA 4 1 Head 39 25" 10-5/8" 15.25"
61" stance . 1 Blade & Tail 59 17.5" 6.5" 36"
. . 1 8′ Tower section 52. 48" 3.75" 3-9/16"
. . 1 8′-12′ Tower section 27.5 48" 2-3/8" 3-9/16"
16′ KFA 5 12′ KFA plus . . . .
79" stance . 1 12′-16′ Tower extension 31.5 48" 2-3/8" 3-9/16"
20′ KFA 6 16′ KFA plus . . . .
97" stance . 1 16′-20′ Tower extension 39 48" 3.5" 3"
24′ KFA 1 1 20′-24′ Tower section 48″ 3.75″ 4″
118" stance

We are dedicated to the design, testing and perfecting of our products.

To Purchase a Koenders Windmill

To purchase a Koenders windmill or accessories, you can Order Direct Online or use our Locate a Dealer form to find the dealer closest to you.

Customize Your Pond Windmill

powder-coated windmillCreate your own custom painted windmill with our wide selection of weather-resistant powder coated finishes. See our Powder Coated Windmills page or call our toll free number 1-888-777-4933 to pick your color selection.