I believe the most practical thing that could be added to the nest thermostat is the ability to turn Eco mode on and off by the use of a schedule.
It’s currently -30 Celsius outside, if my house goes into eco mode while I’m at work, and I come home, it’s going to take at least an hour for the house to heat up, if not longer. So the home and away feature, can’t preheat my house in time, or even close to it. The best solution I’ve heard is the only set your eco mode at 5 degrees Fahrenheit below your room temperature. That’s really not much of an energy savings… My other option is just to turn the Eco mode off and run it off a schedule. If that’s the case what was the point of this expensive thermostat, when the one I had before did that at a fraction of the price.
I’m not bitter about it but I won’t be recommending this product to anyone unless I see this feature added, it simply doesn’t make a lot of sense in this climate, without the ability to schedule the Eco mode (or some other feature that serves the same purpose).
I know, what I am talking about works because I’ve implemented this in my office building. The building turns into occupied mode when the building alarm is turned off. But if I walked in there Monday morning and turn the alarm off, it’s going to be cold in there. so there’s a schedule that turns on every day of the week for a couple of hours, before people are expected to arrive, that allows the building to preheat. If no one shows up, say because of a freak snowstorm, the building will coast back down to it’s unnoccupied set point, after the schedule is over.
I am not a a programmer, I am an build automation technician. So I can’t reasonably implement this change myself.