Picture this: a fire breaks out, smoke begins to spread, and every second counts. The key to ensuring safe evacuation? A well-designed smoke ventilation system powered by the right window actuators. But with so many options, how do you know which one is best for your project? In this guide, we’ll break down their differences, strengths, and ideal applications so you can make an informed choice.

What is a window actuator?

A window actuator is a type of motor for moving or controlling a mechanism or system. It is operated by a source of energy, usually an electric current, hydraulic fluid pressure, or pneumatic pressure.

Stairwell ventilation can be achieved by automatically opening a window within the stairwell. As always this is subject to the minimum free area being achieved when calculated using the method in diagram C7 of Approved Document B. It is recommended that bottom-hinged outward opening windows are selected for efficient smoke evacuation, however, this is not a requirement of ADB. Stairwell ventilators are more commonly used for replacing fresh air in a lobby extract system.

What are the key types of window actuators?

In this article, we’ll explain the different window actuator types and help you decide which one fits your project best. The most common types of actuators for smoke control systems are:

  1. Electric Chain Actuator
  2. Linear or Spindle Actuator
  3. Folding Arm Actuator

window actuators smoke control

Electric Chain Window Actuators

Chain actuators use a flexible chain mechanism to extend and retract, making them ideal for use with top-hung, bottom-hung, and roof windows (not to be confused with skylights). These window actuators provide smooth and precise operation while fitting neatly within the window frame. Electric chain actuators are most commonly used to open corridor windows and are perceived as the aesthetic choice. Due to their smaller dimensions, however, chain drives can lack the power to automate some rooflights or skylights.

For example, electric chain actuators are a great fit for a modern office building where aesthetics matter just as much as functionality. The large, top-hung windows need to open effortlessly during a fire emergency, yet blend seamlessly with the design. This is where a chain drive window actuator shines, offering a discreet yet powerful solution that ensures both safety and style.

Best for:

  • Natural and smoke ventilation in commercial and residential buildings.
  • Applications requiring a discreet and compact design.
  • Windows with limited space for installation.

Key Benefits:

  • Compact and aesthetically pleasing design.
  • Suitable for light to medium-weight windows.
  • Adjustable stroke length for flexibility.

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Electric Linear Window Actuators

Since electric linear actuators are more powerful than electric chain actuators, they lend themselves better to automating rooflights and skylights. Although the greater power is an achievement, visually linear or spindle-type motors can be intrusive and lack the aesthetic appeal desired in modern buildings. Thanks to their strength and reliability, these window actuators are a preferred choice for industrial applications.

Picture a spacious warehouse, where ventilation plays a critical role in maintaining air quality and safety. Skylights and heavy-duty vents must open and close reliably, whether for daily airflow control or emergency smoke extraction. Electric linear actuators deliver the brute force needed for such demanding applications, making them indispensable in industrial settings.

Best for:

  • Heavy-duty smoke ventilation applications.
  • Skylights and large industrial windows.
  • Scenarios requiring higher force output.

Key Benefits:

  • High force capacity for heavier windows and vents.
  • Simple and durable mechanical design.
  • Available in various stroke lengths for different applications.

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Folding Arm Window Actuators

Folding arm actuators use an articulated arm mechanism to push and pull windows or vents open. They are ideal for high-performance smoke ventilation applications requiring fast and reliable opening.

Folding arm actuators are the best window actuators for facades and roofs. Not only are they designed and tested for use in smoke and heat ventilation, but folding arm actuators can also control natural ventilation. Actuators of the “folding arm” type have special kinematics and their high-performance gear (> 20,000 LW) in combination with the stainless steel lever arms is very resistant to variable loads (wind, snow). The symmetrical design and its compact size make this automatic window opener ideal for projects with high aesthetic demands – especially when it comes to large heavy windows. All folding arm actuators are tested and certified according to EN 12101-2 together with various profile series for use as natural smoke and heat exhaust ventilation devices.

To illustrate, picture a bustling shopping centre filled with people. In the event of a fire, the roof vents need to open instantly to clear smoke and prevent panic. Folding arm actuators, designed for rapid deployment, provide the speed and power necessary to keep large public spaces safe, giving emergency responders crucial time to act.

Best for:

  • High-speed smoke extraction systems.
  • Roof vents and larger windows requiring a powerful actuator.
  • Scenarios where rapid deployment is necessary for safety compliance.

Key Benefits:

  • Fast operation for emergency smoke extraction.
  • High force capacity for larger openings.
  • Ideal for top-hung and side-hung windows.

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Folding Arm Actuators for automating roof and skylights

Our folding arm window actuators are driven by innovation and specifically designed to automate roof and skylights. They are backed by a 3-year warranty and calculation software, ensuring your specification and installation are correct. With kinematics and high-performance gearing, combined with the stainless-steel lever arms, folding arm actuators overcome the resistance to changing wind and snow loading that are rarely factored into designs.

Choosing the Right Window Actuators for Your Project

Selecting the perfect window actuators isn’t just about specs, it’s about understanding the environment they will serve. Do you need something subtle for a high-end office, or something powerful for an industrial warehouse? Every project is unique, and considering factors such as window type, force requirements, voltage, and aesthetics will ensure you choose an actuator that fits seamlessly into your smoke ventilation system.

When selecting a window actuator, consider the following factors:

  1. Window Type & Size – Ensure the actuator is compatible with the window’s design and weight.
  2. Force Requirements – Choose an actuator that can handle the necessary force for reliable operation.
  3. Voltage & Power Supply – Select 24V or 230V options based on your building’s electrical infrastructure.
  4. Mounting & Aesthetics – Consider space constraints and visibility requirements.

Final Thoughts

Selecting the right window actuator is crucial for ensuring the efficiency and safety of your smoke ventilation system. Whether you need a compact chain actuator for discreet installation, a robust linear actuator for heavy-duty applications, or a high-speed folding arm actuator for emergency smoke extraction, Group SCS offers a range of high-performance solutions.

Explore our full range of actuators or contact our team for expert advice on choosing the right actuator for your project.

Under the Construction Products Regulations (CPR) it is a legal requirement to use only certified products for smoke ventilation. It is the responsibility of the installer to ensure installations meet the relevant standards. For more information see SCS Group’s Technical Bulletin here.