Cart 0

Fan Control with Aeotec Nano Dimmer

Posted by LiveHouse Automation on

One of the features of the Aeotec Nano Dimmer is that is supports inductive loads in addition to the usual resistive and capacitive loads.

For those of us who aren't Electrical Engineers, that basically means the Nano dimmer can control electric motors such as those found in fans and pumps, as well as lights. So now you can include your ceiling fans in your climate control or scene logic, and you can have push button variable fan speed control that works the same way as your lighting dimmers.

Additionally, you can use a Nano Dimmer instead of a Nano Switch on your Extractor Fans. This lets you take advantage of Affinity Laws to save power and reduce noise, in a similar way we did with Pool Pumps

Apologies for the engineering content. But the key take away here is if you reduce RPM by 10% (hence airflow by 10%), you save 33% in energy costs. You also reduce the noise your fan makes. You probably won't notice the reduction in airflow, but you will notice the noise and energy reduction.

For example, I recently set up a network cabinet in my laundry cupboard to centralise a lot of my home network equipment. The equipment generates a bit of heat so I needed to put an exhaust fan in. My significant other was concerned about the noise that an extractor fan would generate.

As you can see in this video - her concerns were well founded, but my cunning dimmer deployment delivered dividends. 

It also saved a considerable amount of power. 

This represents the difference between $84 and $21 per year in electricity costs. Thanks to a Multisensor 6 I'm able to confirm that at 30% fan speed, the temperature level is kept to the same level as if I'm running it at 80%. Of course, I've been able to add some extra smarts. If the temperature falls below 24 degrees the fan will shut down. If it goes over 36 degrees it'll ramp up to 90% and send me an alert that I might be about to cook my Vera.

I also didn't need to install an additional wall switch and run cables for the fan - Vera takes care of it wirelessly over Z-wave. Plus the motion sensor turns on the light when I go in there - a good example of a single device providing multiple benefits. 

The Technicalities

When using a Nano Dimmer with a fan it must be connected to a neutral wire (3-wire install) and your load must be less than 100W. This shouldn't be too much of an issue unless you're connecting multiple fans. The typical Exhaust/Ceiling fan is between 30-75W. You should also ensure that your fan does not have an existing 3 speed control (resistive type), it must be a TRIAC based electronic regulator which controls speed by variation of voltage. The exhaust fan used here did not have any built-in speed control, it's a straight AC motor.

There are also some extra parameters that need to be checked. Some of these are automatically set by the Dimmer when it's hooked up (Parameter 128 & 130), but you'll want to confirm these are correct. The Dimming type (Parameter 129) must be set for your load, if this is incorrect you may hear an odd noise from your fan as the dimmer regulates the power. These are the settings used for the exhaust fan in this example, you may require different ones so do your research up front.

And that's about all you need to know about controlling your ceiling or exhaust fans using a dimmer instead of a switch. Less noise, less power, only slightly less air flow.

Happy Automating!


Share this post

← Older Post Newer Post →