Help to set up a HA automation based on temp difference.

Forums › Gadgets, robotics, home automation, electronics (including wearables) › Help to set up a HA automation based on temp difference.

peejayw

1913 posts

Uber Geek
+1 received by user: 123

#295512 3-Apr-2022 11:03

I tried this a while ago but got hopelessly bogged down.

I have two temperature sensors, one at ceiling height and one at floor. I want to turn on a ceiling fan when the difference between the 2 sensors exceeds say 5deg.

Any suggestion?

Thanks.

I'm supposed to respect my elders, but it's getting harder and harder for me to find one now.

mattenz

195 posts

Master Geek
+1 received by user: 48

#2896264 3-Apr-2022 16:38

Would you perhaps start by making a template sensor?

This looks like one approach: https://community.home-assistant.io/t/relative-temp-difference/202449

peejayw

1913 posts

Uber Geek
+1 received by user: 123

#2896274 3-Apr-2022 17:11

Thanks Matt, that looks like an avenue to follow.

I'm supposed to respect my elders, but it's getting harder and harder for me to find one now.

mattenz

195 posts

Master Geek
+1 received by user: 48

#2896276 3-Apr-2022 17:12

All good, could then maybe attach it to a thermostat card, got me thinking haha.

davidcole

6099 posts

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Trusted

#2896293 3-Apr-2022 17:54

Having just moved a bunch of my heating rules from openHAB to home assistant I’ve been playing with things like.
Getting temperature from 1 hour ago.
Comparing temp from 1 hour ago with now to get a trend.
Lessening the the min temperature for a thermostat, or the offset from standard value to standard value - trend. Which essentially turns on the heater early.

Also implemented a customer thermostat that uses profiles. Mainly for a boost profile which will manually turn on the heating system.

Doing this was my first challenge for moving off openhab. Then I can port over other things. I still currently use both. But my heating and lighting are driven from home assistant. I like the much lower memory use and being able to write automations (rules in openHAB speak) via phone

Previously known as psycik

Home Assistant: Gigabyte AMD A8 Brix, Home Assistant with Aeotech ZWave Controller, Raspberry PI, Wemos D1 Mini, Zwave, Shelly Humidity and Temperature sensors
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SpookyAwol

638 posts

Ultimate Geek
+1 received by user: 54

#2896824 4-Apr-2022 15:26

If you want to totally overthink it like I do, use node red ;)
Standard HA automation's are fairly flexible, but node red is next level (and Im not even scraping the surface)

The link above looks like it will do the trick.
Look at expanding on the conditions that are available for logical comparisons
https://www.home-assistant.io/docs/scripts/conditions/

peejayw

1913 posts

Uber Geek
+1 received by user: 123

#2896869 4-Apr-2022 16:57

ITS ALIVE!! ITS ALIVE!! 😁

Thanks for all your help, I have got it running and only destroyed a few more brain cells in the process but have learnt a bit more in the process.

I'm supposed to respect my elders, but it's getting harder and harder for me to find one now.