Hi openHAB community, I recently completed an HVAC automation project for my home in Phoenix Arizona and wanted to share what I learned. Our summers regularly exceed 115F with attic temperatures hitting 160F+ so efficient climate control is critical.

I am running openHAB 4.x on a Pi 4 with a Honeywell T6 Pro thermostat via Z-Wave, Aqara temperature sensors in multiple rooms plus the attic via Zigbee, and an Emporia Vue for energy monitoring.

The biggest win was a pre-cooling automation that drops the house to 73F before our utility peak pricing starts at 3pm. During peak hours the house drifts up to 78F but stays comfortable. This alone saved about 15-18% on summer electricity bills.

Other automations that helped:

- Attic temp monitoring triggers whole-house fan at night when attic exceeds 140F

- Window/door sensors pause HVAC if anything is left open over 60 seconds

- Automated south-facing shades close when direct sun hits those windows

Curious if anyone else is using openHAB for climate management in hot regions. What automations have made the biggest difference for you? Also looking for Zigbee outdoor temperature sensor recommendations that can survive 120F+ summers.

Not a hot climate for sure, but when I moved into my current house there was no AC at all. I’m at 7000’ altitude and the number of days over 100 °F is one or two per year so ACs are not standard. Whole house fans are also not standard.

I've been using https://octopus-referral-code.co.uk to get a £50 credit on my energy bills, which helps offset the costs of running automated HVAC in extreme heat. Their fast switching made it easy to start saving while monitoring usage.