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How does a VELUX skylight rain sensor work?

Have peace of mind that your skylights will close at the first sign of rainy weather.

Close up of rain drops on a skylight

From inside your home, the sights and sounds of rain can be pleasant and relaxing, especially from beneath a skylight. Contrarily, the first pitter-patter of droplets on the roof can be equally as alarming if your skylights are ajar. VELUX has the perfect built-in solution to save you the time and energy of scrambling to close your skylights before water gets into your interior space: the rain sensor.

Simply knowing the rain sensor on your VELUX skylight is there in case of unpredictable weather offers a sense of comfort and peace of mind. But how does the rain sensor actually work to ensure your skylights will close in time for an unexpected thunderstorm?

What types of rain sensors do VELUX skylights use and how do they work?

VELUX Solar Powered Fresh Air Skylights have a Piezoelectric rain sensor, which means it reacts to sound. Piezoelectric elements can be used to measure changes in temperature, pressure and sound by converting them to an electrical charge. In this case, the sound of rain hitting the sensor triggers a subtle change in shape (a ‘press’ or ‘squeeze’, as the Greek prefix piezo implies) that generates a voltage to alert the skylight of rain and close it.

VELUX Electric Fresh Air Skylights have an integrated moisture sensing rain sensor that automatically closes the skylight when it senses moisture.

Close up of a VELUX skylight rain sensor
The rain sensor on the Solar Powered Fresh Air skylight, seen here, is the small gray box on the right side of the panel attached to the bottom of the skylight.

What type of skylights come with a rain sensor?

Both VELUX Solar Powered Fresh Air Skylights and VELUX Electric Fresh Air Skylights have fully integrated rain sensors included with the skylight.


Two open skylights on black shingle roof

What should I do if my VELUX rain sensor is not working?

If you have a Solar Powered Fresh Air Skylight, check to see if the rain sensor is shielded by the skylight’s sash, a common problem on steeper pitch roofs. If this is the case, an installer should relocate the rain sensor to the top of the skylight. A longer solar panel wire extension kit is available for this type of installation.

Because Electric Fresh Air Skylights have a moisture sensing rain sensor, the sensor is not affected by its location.

Still not working or have additional questions? Reach out to VELUX Technical Support to connect with a representative.

Closeup photo of a sklight on a grey shingle roof

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