Turnstone provides ventilation equipment, specifically to mining, tunneling, and industrial temperature control markets, that promote industry leading safety and efficiency.

Turnstone Industrial Solutions

271 Gawthrop Drive

Winchester, KY 40391

P: 859-745-8720

A joint venture between ABC Technology Group USA and Calandra Group, LLC


Our fans adhere to the following ISO requirements:

  • Tested to ISO 5801 & BS 848 Part 1

  • Aerodynamic Performance testing to ISO 5801 and AMCA 210

  • Site Aerodynamic testing to ISO 5802

  • Balanced to ISO1940, ISO14694, and ISO10816 standards.

  • Tolerances to ISO 13348 – AN3

  • Vibration level tests to ISO 14596

  • Efficiency testing – ISO 12759

  • Welding Standards – ISO 3438 and ASME 9

  • Safety Standards – ISO 12499 and EN 14461

ToughVent’s aerodynamically tested and optimized design provides a ventilation solution that delivers maximum air power at the highest energy efficiencies. 

Turnstone Ventilation Systems and affiliates offer a turnkey solution to underground ventilation challenges. Rather than being just a seller of ducting and fans, we aim to combine numerous disciplines to provide a total system solution.

The ToughVent range is suitable for use in auxiliary applications and includes booster fans and bulk air cooler fans for use in underground operations.



  • Integral inlet guide vane and aerofoil impeller nose cone.

  • Variable pitch full aerofoil section cast steel and aluminum blades.

  • Fabricated steel hub assembly.

  • Steel aerofoil section rotor nacelle assembly.

  • Heavy duty rollover terminal box to IP65.


  • Upstream guide vane to pre swirl air onto impeller.

  • CAD enhanced nose cone on the impeller for improved efficiency.

  • Variable pitch steel impeller allowing for task-specific duty application.

  • Steel rotor assembly fully welded to the inside of the casing and onto a motor mount nacelle adding structural strength.

  • Modular impeller track providing double protection for the fan on this critical area.

  • Motor is flange mounted at the drive end bearing, onto a machined surface on the nacelle and also has fabricated struts, supporting the back of the motor.

  • An optional air straightener can be fitted down steam of the impeller to prevent air swirl onto flexible ducting.