Labs Idea #15: Anti-Fogging for Bathroom Mirrors
Author: Sensirion Innovations Team
April 2018
Motivation/Summary
If you like hot showers, you know the issue of a completely fogged mirror after leaving the shower. There are heated mirrors available, but they heat constantly and therefore waste a lot of energy. With a humidity sensor the heating can be automated and therefore energy consumption can be drastically reduced.
Approach/Measurement
Condensation on the mirror corresponds to a too high relative humidity. By a given absolute humidity of the air, only the temperature of the surface influences the relative humidity. By heating the surface, the relative humidity can be lowered and condensation can be avoided. A foil heater is used for this purpose.
Sensirion humidity and temperature sensors are accurate and fast enough to detect early if someone takes a shower in the same room.
Implementation
The SHT senses the humidity and temperature of the air. For this simple implementation, the placement is not critical as long as the sensor is not heated significantly above air temperature. The power supply is attached to the bathroom lighting, such the circuit is not powered when nobody is inside the bathroom and furthermore the power-on event can be used as a trigger to preheat the mirror. If that is not possible, some modifications to the event logic are necessary.
A sample implementation can be found here.
Going Further
Ideally the anti-fogging feature would be combined with a smart mirror which can display information. Please contact us if you plan implementing this or already have.
To improve performance and especially efficiency, algorithm and physical implementation can be improved. Please contact us for support.
Patent Information
No information or recommendation presented on this website do absolve you from the obligation of investigating the possibility of infringement of third parties’ rights and, if necessary, clarifying the position.
Related Products to this Article
Follow Us
Your Contact to Sensirion
Contact our sensor experts:
Here you find the nearest distributor in your area:
Find out where we are located: