Good questions, cabinhost!
- Windows are definitely a problem that can rack up your energy bill. Your question has a few parts and there are different solutions so I’ll try to lay them out well.
To start, you can definitely have your window sensors activate your thermostat after 5 minutes. There’s no out-of-box solution for this so you would need something like a Homeseer ZWave Pi (ask me specific questions about the system if you’d like). Then you can set up a trigger along the lines of "if a window goes from closed to open, start a countdown. if it’s open for 5 minutes, turn off the thermostat.
Another simple solution would again use the window sensors and an interface such as Vera, SmartThings, or Homeseer (and lots of others) then just check on your phone to see if any windows are open when a guest leaves.
- Your second question is pretty simple. You are probably thinking of the Ecobee thermostat with room sensors. Those can detect if someone is sleeping vs. not in the room but must be pointed at them. This then adjusts the set temperature to the room they’re in (example if they set it to 21 degrees, it’ll make sure the room they’re in is 21 instead of the room the thermostat is in).
If you want the system to shut off or go into eco mode when no one is home, again you need a Zwave hub (homeseer, smartthings, etc) and your own motion sensors. Those would need to be in pretty much all rooms people might hang out in, and then you can set them so if none of them detect motion, the thermostat goes into eco mode.