BLUF (Bottom Line Up Front): I want to see how many people are looking for controlling the A/C zones in their home with Home Assistant using schedules and presence combined, but not using someone else’s API or cloud service. This is something I want to build and see if other people would prefer it too.
See bottom of post for proposed solution
The current scenario:
I recently bought a mobile home and installed my nest thermostat. I have home assistant running and linked to google cloud, controlling the thermostat based on my wife’s location (she likes it set to 72°F when home, but has an odd schedule with work so a basic HVAC schedule does not work, and the Google presence sensing is not enough because she likes it cool when she gets home).
This works relatively well because I have multiple geo zones that set the thermostat to 78°F when she’s within 30 minutes of the house, 75°F when within 15 minutes, and 72°F when she enters the house (the HA app on her phone updates her location from GPS). The tiered structure is designed such due to her traveling job having one stop within 15 minutes of home (I work 11 minutes away and we also share one car). We get electricity savings because the system is not running full blast when we are not home, but the system is always ready for her when she does get home (side note, the A/C is not totally off when not home because we have pets that could overheat).
Another issue I have is that the thermostat is at the other end of the house from the master bedroom. She likes the temperature at 70°F during the night. The temperature at the thermostat stays ~70, but the master bedroom (right near the HVAC) gets either really cold or really hot (based on whether we have the vents adjusted or not). The hotter it gets outside, the colder it gets in our bedroom.
To start data logging on this and start solving the issue, I bought a Govee BLE thermometer/hygrometer for $12 on Amazon, put it in the bedroom and configured HomeAssistant to listen for it (since BLE is not paired but just sends out beacons with the data).
I found the bedroom temp got no lower than 65°F and as high as 73°F, sometimes multiple instances a night. When it gets this high, my wife can’t sleep and kicks off the covers, then the A/C kicks on and freezes the both of us out.
What I want:
- Master bedroom consistently cool at night (as close as possible)
- The rest of the house can get up to 78 after 10pm for all I care, and cool down a little around 6:30 am before work
How I want to solve it:
- Use Home Assistant to regulate the temperature in the various rooms
- Replace the Google Nest thermostat with something that works with HA without cloud requirement
Research on already-existing wheels:
- Flair Smart Vents /w Puck
- Keen Smart Vents
- Ecobee Thermostat /w remote sensors
Issues with above:
- Flair: This system seems to be the most complete, except the temperature sensors are at the vent, rather than in the room, causing the system to always read lower than what the room really is. It’s also the most expensive, and relies on the cloud.
- Keen: These seem to only control the vents, not the HVAC, and is expensive & relies on the cloud
- Ecobee: This is just a thermostat with remote sensors, and has no zone control but averages the house temp across all sensors. Also requires cloud access.
- Other systems don’t have the 4x10 vents needed for my home, nor do they have rectangular ducts
Build my own smart vents and thermostat:
- Using ESP32 (for each of the vents and replace the Nest)
- Hobby servo motors
- No batteries on the vents themselves (for my system, I’ll be running wires from each vent through the duct, as it’s all one level)
- Build a thermostat add-on or integration to manage this ecosystem
EDIT 2022-07-14T16:20:00Z: Updated formatting and added screenshot of bedroom temp, clarified not having batteries on vents specifically
I know it was / may have been a lot to read. Thoughts or feedback?