Developed by the HSK R&D team on the principle of “quality in product and production” Flexline series air handling units, are capable of performing all indoor air conditioning tasks with success under all operating conditions thanks to their superior thermal and mechanical performance. In addition to 100% fresh air units, HSK also produces mixed air and heat recovery air handling units. HSK steel carcase ir handling units are available under the name of Quickline with capacities of up to 20,000 m³/h, and under the name of Flexline with capacities of up to 20,000 m³/h. Maximum air volume is specified as 100,000 m³/h for Flexline series air Handling Units. While all radial fan types are used, the frequency converter is offered as an option. A switchbox is required for this option. Maximum air volume is specified as 20,000 m³/h for Quickline series air Handling Units. Since plug fans are used as standard equipment, the motor is directly coupled, hence eliminating the use of belt and wheel. This also eliminates efficiency losses, as well as the operational costs resulting from belt replacement and line adjustment of wheels. Since directly coupled fans are manufactured as standard equipment along with the specially developed frequency converter switchboard, energy can be saved by reducing the air volume during times when the facility operates with slow demand, using the frequency converter with the pressure or temperature sensor, without requiring the control panel. Since the frequency converter also assumes the functions of the switchboard, it eliminates the need for the user to purchase a panel.