HVAC / Smart Vent Zoning control through HomeAssistant, no internet required (but recommended)

[nuetron (Nathan Spin)]

Lots of good feedback!

@stevemann

I don’t think that a hobby servo motor would have the torque needed to move a typical duct vane, but maybe one of the 25kg might.

Very true. I just bought a 3D printer (for this and other projects, arrives on Saturday) so was hoping to build it into the frame of the vent itself, rather than duct vanes.

@stevemann

Use 18/4 thermostat wire. I never thought of running wires through existing ducts. Thermostat wire is rated for -20ºC to +105ºC, so be aware of the output temperature of the furnace. In fact, fire it up and measure the temperature at a few locations where an ESP would be. Mine puts out 110°F at the vents closest to the furnace. You wouldn’t want to spend all summer perfecting the system only for it to literally fry in the winter.

Why 4-conductor? 2 for the servo power and 2 for the ESP. The servo motor can draw quite a bit of current so you want to power it separately from the ESP, otherwise moving the servo could reboot the ESP.

Good idea. I really don’t want the wire melting… I was thinking about running the wires through the vent using a remote controlled car, because of the level surfaces.
Also, you gave me an idea. Why not build a control board into the AC unit and have one ESP32 in there that controls all zones, and the unit as well? The wires would still run to each vent, with one servo at each vent. I might also want an airflow sensor and possibly a temperature sensor at the vent, just to make sure if the vent should be open and I don’t have airflow, throw an error. Especially, all vents are closed, turn off the system to protect itself. I don’t want the HVAC/furnace frying or causing a fire.

@stevemann

This sounds like a perfect project for ESPHome. I know you don’t like batteries, but for the temperature sensor you could use Zigbee devices and change the batteries when you change the smoke detector batteries.

Well… I should have clarified. I didn’t want batteries powering the vents, because of the system possibly failing to work and getting damaged. I think the Govee BLE room temp sensor is totally fine, especially since I can monitor its battery power too via HA.

@stevemann

My go-to board is the Wemos D1 Mini. I buy clones from AliExpress 5 at a time because they are only $5. I’ve only had one casualty, and I’m not sure it wasn’t something I did. Even an ESP-01 ($1 each) would be sufficient.

Definitely will investigate.

@stevemann

One step at a time.

Thank you! I do have a habit of building elaborate designs in my head and then they don’t work out on paper. Step by step is something I am fighting for. Thanks for the encouragement!

@stevemann

Don’t even think about presence detection yet because there’s a lot of solutions.

I think I was using the term loosely (e.g. “X phone is detected at home”), but yes, that is something I do want to be able employ in the future (possibly PIR modules).

Again, thank you for the feedback. I typically try to do things on my own and not get input from other people, so this is requiring me to step out a little.