My Dad has recently had a new Bathroom installed and we took the opportunity at the design stage to include a ceiling mounted Hue Light Fitting, Paired with a Hue Motion Sensor – to finish off the fresh looking bathroom.
The installer had let us know at the design stage that an extractor fan would need to be installed to comply with current UK Legislation, so it came as no surprise that when we initially switched on power to the Hue Light Fitting that we heard the low buzz of the extractor fan running.
We exited the bathroom and as expected the Hue Fitting dimmed and finally switch off. We were aware that the extractor fan was individually powered with a connection to the lighting power purely to trigger the fan to start, also run on for a short time after the light has been switched off.
We collected up the tools and waited patiently out of the range of the motion sensor for the fan noise to cease. If you have any idea why I am writing this article – of course you understand what happened next.
Absolutely nothing – we waited and waited cursing the time delay setting as being too long and then coming to terms with the realities I asked my Dad how the installer had said he was going to connect the fan to the lighting power accounting for the power to Hue Fitting being on continuously.
He confirmed that the installer had not come across a Hue Light Fitting previously but had said he was confident he would able to install it.
The Problem – In a nut shell – as the power to the Hue Light Fitting is permanently on, it logically follows that the extractor fan trigger is permanently live and the net effect is the extractor fan is running continuously.
Bugger – I did a quick bit of analysis to come up with a few solution options:
- Potentially install a Humidistat to trigger the fan, but that would need to be mounted and cable run to it potentially disrupting the fresh decor.
- Potentially tap into the power on the luminaire inside the Hue Light Fitting to trigger the fan when the light is on, but I believed there to be a risk of the fan trigger drawing too much current and damaging the circuitry. Also I didn’t know how accessible the connection would be and I guess this method also voids warranty.
- Potentially modify the wiring in the loft to insert a switch into the fan trigger circuit, which closes at the same time as the light is switched on. The wiring in the loft is easily accessible being simply connected in a single junction box.
The final option to insert a switch into the fan trigger circuit seemed to satisfy our needs, but only a few minutes of creative thinking was needed to discount all straight forward options.
The Solution – I then resorted to google to see if Hue had a solution to close a switch which could be triggered from the motion sensor, which of course they don’t but I did come across the Fibaro Switch which was apparently Apple Homekit compatible. I zoomed across to Amazon and ordered this.
Dad kept reassuring me that the fan noise was not audible when he did not have his hearing aid switched on – however, I don’t know about you but leaving the fan running constantly did not hit the mark for many reasons, hearing aid or no hearing aid.
So the Fibaro switch displaying the Homekit badge was delivered and a quick review of the schematic diagram gave me an idea. I will not confuse you with the enclosed diagram which is designed to switch on a light.
Deploying the Febaro Switch – The diagram below shows simply, how I connected the Fibaro Switch – providing power to the device and connecting the switched output to the Extractor Fan Trigger.
Setting up in the Home App – Having connected the wiring as above – it was time to register in the Apple Home App. There was no need to install the Fibaro App. In the IPhone I simply went to the Home App and tapped the plus sign selecting – Add Accessory. Holding the IPhone I pointed the camera at the Device ID found on the back of the Instruction Manual for the Fibaro Switch. Having captured the ID the instructions were simple to follow.
Progress So Far – once the Fibaro Switch accessory was setup – the Switch showed as on and the extractor fan burst into life. Using the switch in the Home App the fan trigger was switched off and the fan ran on as expected until the pre-defined time delay built into the fan itself expired and the fan switched off. Switching on again started the fan as expected.
At this point we had completed the hardware and control setup and I had already thought of a number of options available to create the trigger to start the fan. I knew it may come down to trial and error and selected the easiest most straight forward method.
Home App Automation – in the bottom right corner of the Home App I selected – Automation. Then selected >> Create New Automation >> A sensor detects something – following the instructions to Switch the Fibaro Switch On when motion is detected by the Hue Sensor in the Bathroom.
Conclusion – When Motion is detected in the Bathroom the extractor fan starts and if the ambient lighting level is below the threshold the light comes on – Voila. The settings in the Hue App control the Dimming and auto switch-off timer effect for the Hue Light Fitting, but as the state of the Fibaro Switch is simply switched on or off directly in the Home App these effects have no visible impact on the performance of the extractor fan – Simples.
Have you ever wondered how to take a real world input from an ordinary piece of Electrical Hardware to control something in the Home App? I notice in the Schematic for the Fibaro Switch that there is an input designed to enable a push-button to toggle the switch… but that is a whole different story.
Buy the Fibaro Switch – On Amazon