Fancy new thermostat

[glatt]

Another update to the Nest thread. We're just coming off a winter of heating, and I can report on how the Nest did. We used less fuel than we did last winter. And this winter was colder on average than last winter was. The Nest saved energy compared to the previous programmable thermostat we had.

I was confused by this, because I thought we had the previous thermostat set up just right. I didn't understand how the Nest was saving us fuel. It turns out that the Nest was able to learn how long it took for our radiators to heat the house and how long they continued to heat the house after the thermostat shut the heat off. Previously, we would call for a certain temperature, and the old thermostat would run the boiler until that temperature was satisfied. Then it would shut the boiler off. The hot water would continue to circulate through the radiators, and the house would get hotter than the temperature we asked for. If we had programmed the heat to turn off when we left the house in the morning, the house would still be toasty for a hour or so after we left.

With the Nest, it learns how long it takes to heat the place up, and how long the radiators will coast, still heating the house, and it runs the heat for a shorter amount of time to just give us what we ask for.

I don't notice any less comfort. In fact, I felt like it was warmer in the house. So the Nest is giving us the heat we want, when we want it. And isn't heating an empty house.

You probably want numbers, but I don't have the bills in front of me. But we easily used fewer therms this winter than we did last winter.