What is Time-to-Temperature?
With Time-to-Temperature, the Nest Learning Thermostat displays how long it will take for your home to reach the temperature you choose, so you won’t be tempted to set it too far.
Use Time-to-Temperature to help you save energy. Cranking the heat up to 90ºF/32ºC won’t make your home heat up any faster, but could waste energy if you don’t remember to turn it down. The longer you are heating or cooling your home, the more energy you’re using. Just choose a comfortable target temperature and the Nest Learning Thermostat will tell you how long it will take to get there.
When you first install your Nest Thermostat, the words “heating” or “cooling” will be displayed when you change the temperature. After the Nest Thermostat has had a week or so to learn, it will instead display an estimate of the time it will take to heat or cool your home to the selected target temperature.
The Nest Learning Thermostat will only display the estimated Time-to-Temperature for manually set temperatures, not scheduled temperatures. Once the target temperature is reached, the Time-to-Temperature display will disappear.
The Nest Learning Thermostat estimates Time-to-Temperature in increments of five minutes. If it’s less than ten minutes until the temperature you’ve selected is reached, the display will read, “less than ten minutes.” If it’s more than two hours, the Nest Thermostat will read “in 2+ HR.”
The Nest Thermostat's Time-to-Temperature estimate will get more accurate as your Nest Thermostat continues to learn and as the current temperature gets closer to the target temperature. It’s like taking a long road trip with a GPS Navigation Assistant: when you start driving from San Francisco to LA, you might not be sure how many minutes it will take to get there—you just know it will take anywhere from five to eight hours, depending on whether you get lucky with traffic on the freeway. By the time you’re on the outskirts of LA, your GPS is pretty sure that it will take between fifteen and twenty minutes to reach your destination.
This is also why the Nest Thermostat won’t display an estimate if continuous heating or cooling is needed to maintain the temperature that you have selected or if the temperature fluctuates unexpectedly. For example, if an extreme heat wave means your AC can barely keep the temperature down even when it’s constantly cycling, the display will simply read, “COOLING.”
When the seasons change and you switch your Nest Learning Thermostat between heating and cooling for the first time, the Nest Thermostat will need to learn to estimate Time-to-Temperature for a new system. Next time there’s a change of seasons, the Nest Thermostat will remember what it has already learned.