Home Ventilation System - Home Automation

For a year now I have worked with automating stuff in my house. I started off using Homne Assistant as this was a cheap way into it all - but I never quite got it to work as I hoped. I therefore went for the Smartthings V2 (UK version) hub and I have never regretted it. It is a superpowerful hub connecting to almost any standard out there. I have Zigbee (Xiaomi buttons, sensors, IKEA Trådfri bulbs, Philips Hue bulbs) and Z-wave (switches, dimmers, water sensors etc)....I am probably up to about 50+ physical smart units.

Recently we have done a lot of initiatives to reduce power consumption, and my latest idea has been to install a "air mover" from the main floor (where we have a fireplace) down to the basement wardrobe room. We have an old house with high ceilings (280cm). The idea is to move the warm air in the ceiling that else would be wasted down to the basement. The basement is also opened up so the warm air will flow up hence creating air circulation. 

 The system should also be controlled automatically using smartthings. It should be able to be turned on/off and the fan speed controlled either using the mobile interface or in automations. Turning the fan on/off is simple, here it is possible to use a smartplug for the fan. The challenge was to find a way to regulate the speed of the fan. There are tons of smart products for regulating lights but almost nothing for smart regulation of fan speed. I looked all over the web but could only find some USA  versions with three settings LOW/MED/HIGH. This was not good enough so I therefore bought a manual speed controller that I could "smart up". I therefore designed a 3d printed knob using a SG09 servo.  As always I draw it in Onshape and is designed to replace the manual knob. 

To control the servo and connect it to Smartthings I used the ST_Anything device handler, this is a fantastic addon enabling users to connect sensors and actuators to your smarthome system using e.g. ESP8266 wifi enabled board. This is supercheap stuff - you can pick up a board from aliexpress for under 3usd - amazing!

The video below shows the fan controller in action. 

Furthermore I also created a "fresh air channel" for the fireplace. All fireplaces needs fresh air - by installing a channel for this close to the fireplace the thought is this should reduce draft when in use. The downside is that you will have a channel also providing cold air when not in use - hence it should be possible to close the ventilation when not needed. This of course also can be done smart - I therefore bought hvac valve with motorized valve. 

The video below shows how the fresh air ventilation is controlled using smartthings. Later I will create automations using temperature sensor that will "sense" when the fireplace is in use and open/close the valve accordingly. 

A problem with ventilation is sound. To reduce the sound I have created a "sound trap".  This reduces the sound as the air need to travel through channels - as I have an external fan. Image below shows initial drawings and the work in progress. The result was successful - the sound was reduced significantly.