UL Approves Window Actuator for Automated Natural Ventilation

Last year, WindowMaster released a window actuator that comes in three variants for automated natural ventilation. The actuator contains attributes and features, that have been sought by the market along with TrueSpeed technology. Now the actuator has also been UL listed for the North American market, which enables enhanced use of natural ventilation.

“The WMU 831/851/852 approval builds on the commitment of WindowMaster to offer building professionals a range of possibilities that address the needs of energy efficiency, architectural aesthetics and healthy indoor environments,” says Nicolaj Rasmussen Shabtai, chief product officer of WindowMaster. “We therefore designed the actuator from the very beginning with the purpose of it passing the UL test and approval process”.

Up until last year, WindowMaster offered one automated window actuator classified in the medium size chain product portfolio (300-500N). However, with the new window actuator in three variants, North American building professionals now have more variety to pick from. The three variants are different in strengths and speed, which enables customers to pick the right actuator depending on their specific needs. They all come with an entrapment protection function, which enables them to be integrated into windows that are positioned below 8 feet from the floor.

Furthermore, a PCB has been developed to the three actuator variants. The PCB allows more programming space and an builtin five terminals connector, which will ease installation of the actuator and let the user directly connect the cable and pressure safety strips into the connector plug.

One Actuator – Three Variants

The WMU 852/851/831 belongs to the medium chain product group in the WindowMaster actuator portfolio. The product has been developed in three variants, each targeted to its specific group of performance required for the job and each of them UL approved. Where the WMU 852 is for high performance on extra force and longer strokes, the WMU 851 is for extra force and minimum current consumption, and finally the WMU 831 was made for minimum current consumption and medium force. Together the three medium chain WMU actuators, which all come in the same sized housing, provide more possibilities to make smart choices for future façade windows.


All three variants of the WMU actuator come with TrueSpeed technology developed by WindowMaster. With TrueSpeed it is possible to synchronize the opening of all windows. While MotorLink by WindowMaster allows you to connect up to four actuators so you can open the automated windows simultaneously, TrueSpeed allows you to connect the MotorLink lines meaning that you can open all windows in sync. Moreover, TrueSpeed can slow down the actuator movement (down to 1-millimeter per second), which enables the actuators to run silently and give the user more control.

Styling and Specifications

The window actuator variants deliver up to 500N in a classic WindowMaster façade actuator. This is strong for a medium sized chain actuator. Multiple window types can use the WMU 852/851/831 meaning that the product will be available for a variety of contractors, façade builders and others using, planning, or building with natural ventilation.

Be the first to comment on "UL Approves Window Actuator for Automated Natural Ventilation"

Leave a Reply

%d bloggers like this: