Tony Brobston's 3D-Printed ESP8266 Smart Vents Put Every Vent in Your Home Under MQTT Control

Maker Tony Brobston has dramatically improved his home heating and ventilation system with the development of a 3D-printed smart vent, which uses an Espressif ESP8266 to open and close depending on MQTT messages in order to provide per-vent control over airflow.

"This project contains most everything needed to 3D print, assemble, and flash an MQTT Smart Vent," Brobston writes of the project, which is amusingly called Yet Another Smart Vent. "[Its philosophy is:] Local control; external integration; ease of use."

The heart of the system is the smart vent design itself. 3D printed and tested in 2×10, 4×10, and 6×10 sizes — with 2×12, 4×12, and 6×12 variants designed but not yet tested — each smart vent is powered by a Wemos D1 Mini with Espressif ESP8266 microcontroller, a DC Power Shield add-on, and a Batan B2122 servo motor.

Once powered — from either mains power via an individual power supply, a centralized 24V power feed, or a battery pack — the vents connect to the local network and begin sending MQTT messages relating to whether each vent is open or closed — and, naturally, listening for messages to tell them to change their states.

The system is designed for easy integration into existing smart homes, including Home Assistant, and provides per-vent control over heating or cooling airflow. Brobston does, however, have some advice for those looking to implement the smart vent system: "It is recommended to have a Static Pressure Regulating Damper installed between the main return and the main plenum," he explains. "This will even out the static pressure that increases or decreases by opening or closing vents.

"If the previous recommendation is not possible, it may be possible to partially mitigate the static pressure issue by only closing vents (that are in a closed state) to 80 per cent closed when the number of closed vents is greater than 75 per cent. This will be a feature implemented in mqtt-hvac-vent-control in the future."

The project is available on Brobston's GitHub repository under the reciprocal GNU Affero General Public License 3.