Goal: vent the attic when outdoor air holds less moisture (g/m3).
Have: 4 aqara temp- & humidity sensors (2 in attic, 2 outdoor), 2 fans powered through a (single) zigbee smart plug.
Want:
- from RH & temp measurements (plural, 2 sensors in both locations) calculate absolute humidity (g/m3) outdoors, and in the attic
- if AH outdoor is < AH in attic, switch plug on to start fans.
- Would be great if (hourly?) AH is logged “forever” for further analysis in the future.
- Stretch goal: graph the changes in (outdoor & attic) AH when venting, so I can evaluate the frequency and effects of venting.
- Strech goal 2: a card to visualize both outdoor sensors’ RH, temp & calculated AH, as well as both attic sensors’ RH, temp & AH
I can sort out the math myself so feel free to use a placeholder expression. I mostly need help with how to write and structure the automation to make it robust and maintenable. How do I best average the sensor readings (avoiding bugs if one goes offline)? How do I log hourly values?
Grateful for any help and advice!