Article Summary:
Early-On is a Nest Learning Thermostat feature that turns heating or cooling on early to get you to the temperature you want at the time it’s on the Nest Thermostat's schedule.
Early-On is a comfort feature that the Nest Thermostat makes available for forced air systems that blow air through vents in your home (including furnaces, air conditioning and heat pumps.) It calculates exactly when to turn on heating or cooling so your home will reach the target temperature you’ve set in your thermostat schedule, right on time. To do this, it takes into account the weather, and what your thermostat has learned about your home.
Early-On works a lot like pre-heating the oven when you’re making cookies. You typically start heating your oven a few minutes ahead of time so that it’s the right temperature when you’re ready to put your batch of cookies in to bake. Now imagine that your oven knew you’d be done mixing the dough at 5pm and would automatically turn on early to be 350°F/177°C right at 5pm.
Your Nest Thermostat takes just a few days to learn how quickly your home heats and cools and what temperatures you like. However, Early-On will continue to adjust when it starts heating or cooling even after your thermostat’s initial learning period.
With our improved learning algorithms, the Nest Thermostat can more precisely control your system depending on the current weather, what the forecast is for the next few hours, and how warm it is in your home. With this improved data, Early-On can begin heating up to 5 hours before a scheduled temperature (it used to be limited to 2 hours). For instance, if your home is slow to heat up, this helps your thermostat meet your scheduled temperature on time, maximizes energy savings, and maintains the temperature you set.
What does Early-On do?
When you first set up your Nest Learning Thermostat, Early-On will be off. This means that the Nest Thermostat will not begin heating or cooling before a scheduled temperature. For example, if your schedule has a target temperature of 72ºF/22ºC at 6pm, your Nest Thermostat will start heating at 6pm. So your home may not reach 72ºF/22ºC until much later, depending on how long your system will need to run to reach the target temperature.
With Early-On, the Nest Thermostat will use what it's learned about your home and will turn the heating or cooling on before the scheduled time. In the example above, the Nest Thermostat might start heating at 5:30pm to get your home to 72ºF/22ºC at 6:00pm.
Early-On will continually adapt to the weather forecast and how fast your home heats up or cools down so it can improve its Time-To-Temperature estimates and keep you comfortable while saving energy. For example, on a cold day, the Nest Thermostat might need to start heating at 5am to reach your target temperature by 7am. But on a mild day, the Nest Thermostat may only need to start heating at 6:50am. With Early-On, the Nest Thermostat will calculate how early it should turn on to get to your target temperature on time without wasting energy. See the diagram below to compare the Nest Thermostat's behavior with and without Early-On.
How does Early-On work?
The Nest Learning Thermostat knows how early it needs to turn on because it continually calculates the Time-To-Temperature (the time it takes your home to get from the current temperature to the temperature you want). So it knows when to turn on the heat or the AC in order to reach the temperature you want on time.
When Early-On starts your system varies based on factors like the weather and how long it's taken to heat or cool your home in the past. However, Early-On won't pre-heat or pre-cool for more than five hours. This helps ensure that it won't waste energy and that your home will reach all of the temperatures in your schedule on time. So if your house is 50ºF/10ºC in the afternoon while you're at work and you want it to be 72ºF/22ºC when you come home at 7pm, Early-On may start heating as early as 2pm. Because the Nest Thermostat can tell your system to start heating (or cooling) up to 5 hours ahead of a scheduled temperature, it would be very rare that your home wouldn't reach your desired temperature on time. However, it could happen because of things like extreme hot or cold weather conditions, if you have a poorly insulated home, or if there's an issue with your system.
So, why wouldn't I want Early-On?
There are a couple reasons why Early-On may not make sense for your home:
- Your system is noisy: In some homes, heating (or air conditioning) is loud enough to wake you up. With Early-On, the heat will come on at a slightly different time each morning. This might be a nuisance, and you may want to turn Early-On off.
- Early-On may use more energy: Turning the heating or AC on at an earlier time will necessarily mean you're running it longer, but energy use will vary in every home. We suggest trying out Early-On for a few days and looking at your Energy History in the Nest app. Do you see a lot more energy use? Is it due to the weather or another cause?
How to read the Nest Energy History with the Nest app >
Why should I use Early-On instead of simply adjusting my schedule?
You probably tweak your schedule so you're comfortable on a typical day. So if you usually wake up at 7am, you may set your schedule to start heating at 6am each morning to ensure that it gets there on time. But then the weather gets mild. With Early-On, the Nest Thermostat will calculate the Time-to-Temperature each day and start accordingly. On a mild day, it might only need to start heating at 6:50.
Early-On is great if you've been guessing and setting your own “Early-On” temperature in your schedule. Now you can set your schedule for the temperature you want when you want it, and Early-On will take care of the rest.
What kinds of systems does Early-On work with?
Early-On is only available if you have a forced air heating system or if you have an air conditioner. Because Early-On is automatically incorporated into Heat Pump Balance and True Radiant, it won't appear as a stand-alone feature if you have a radiant system or heat pump with auxiliary heat. If you have a heat pump with auxiliary heat, Early-On will only be used for cooling, not heating.