Ventbot HVAC Booster

HVAC – heating, ventilation, and air conditioning – is a wonder of our modern world. Unlike our ancestors that had to make do with localized fires to keep warm, or human-powered fans to attempt to keep cool, modern homes and buildings can simply set a value on a little box to keep the temperature approximately at the same level.

Central air conditioning does have one problem; however, in that vents far from the HVAC unit may not blow as effectively as those that are closer to it. To compensate, booster fans can be used to increase the airflow at these far-off locations. If you’d like to make your own booster device, with the ability to integrate with a home automation setup, then the Ventbot by Bill Carpenter may be just the solution.

The device uses a bank of PC-style fans to accelerate air at a fan duct, held in place via 3D-printed mounting brackets. Fans are controlled via a custom PCB, which mounts an ESP32 module and uses an external BMP280 sensor to turn the fans on based on a low or high-temperature trigger. PWM control is implemented to allow the fans to ramp up and spin at less than 100% as needed.

The system employs ESPHome as its software framework, which integrates nicely with Home Assistant, allowing it to fit into your overall home automation system. The writeup gives a very thorough explanation about how to construct one of these, and the build files are up on GitLab. You can also see a quick demo of the system running fans outside of a vent in the video below.