Lijan Greentech is Manufacturer and Supplier of Turbo Roof Ventilator Fans. We do Installation also. Roof Ventilator Fans Helps to Reduce Heat Inside Buildings and Ensure Ventilation. Wind Energy is Used in Turbo Roof Ventilator Fans. 24" is Most Common Throat Size of Roof Ventilator Fan. Number of Roof Ventilator Fans to be Installed is decided by Volume of Building, Working Conditions in Building, Average Wind Speed in the Locality and Capacity of the Ventilator Fan. As a thumb rule, one 24" Ventilator Fan is Sufficient for 500 ft2 Floor Area in Normal Height Conditions without Any Specific Source of Dust or Gases. Installing Ventilators Perpendicular to Floor Level Increases Life of Fans. Many Roof Ventilator Fans are Found Rotating Slowly or Stop Due to Faulty Installation. Lijan Greentech have Professional Experienced Service Team for Installation of Roof Ventilator Fans.