[drsim]

My Velux roof windows do this automatically for me every day. Works great as they won't open if it is raining or too cold. Sucks that the radiators don't turn off at the same time, so some wasted energy there.

[Empact]

Another automatic option for achieving these air quality goals is to use an HRV/ERV for continuous fresh air in the house, as they do in Passive House construction. Doing heat exchange between the outgoing and incoming air makes it a very energy efficient system. https://en.wikipedia.org/wiki/Heat_recovery_ventilation https://www.zehnderamerica.com/heat-recovery-ventilator/

[karolist]

Do you have any control of the radiators? I have Velux GGU windows too and plan on doing Home Assistant integration for precisely the reasons you mention plus some automatic shading based on sun position or light sensors. For this I understand you need a KLF200 interface [1] and of course HA integration [2], then the integration possibilities are pretty much endless.

1. https://www.baubay.de/home-interface-velux-klf-200.html

2. https://community.home-assistant.io/t/velux-kfl200-ha-config...

[drsim]

I have Tado TRVs and do have a HA instance. I’m stuck though, as I like the functionality from Tado like home/away, and VELUX like the automations. I’m not sure I could get as good a result by coding that all up in HA.