How Smart is Your Thermostat?

How Do Smart Thermostats Work?

Regular thermostats let users adjust temperature targets and then wait for the heating or cooling system to achieve the desired temperature. Programmable thermostats let you set different temperature targets for different times of the day; some even let you set different temperatures on different days of the week.

But programmable thermostats have horrible user interfaces. A study published in the July 2015 issue of the journal, “Energy Research and Social Science,” found that 40% of programmable thermostat owners don’t use the available programming features; 14% of them couldn’t even find the programmable settings! Consequently, many programmable thermostats are left in “permanent hold” mode, effectively making them just regular thermostats. Smart thermostats eliminate much of the pain and error of programmables.

The best smart thermostats learn from the behaviors of a home’s residents when to adjust temperature automatically, and they also allow users to control heating or cooling remotely. Motion sensors in the thermostat detect movement to inform the thermostat that the home is occupied. (The sensors are generally aimed high, so they don’t pick up stay-at-home pets.)

Over the course of a few days, a smart thermostat learns what time you get up in the morning, how long it will take the heating system to achieve your desired temperature, and programs itself to start heating at the proper time. If you sleep later on weekends, the thermostat will take that habit into consideration, too.

When no one is in the home, the thermostat targets an energy-conserving temperature, e. g., 60 degrees in winter or 85 degrees in summer. If the thermostat expects people to come home around a certain time, it starts heating or cooling early enough to achieve the desired “occupancy” temperature by that time.

Basically, all you have to do is set target temperatures for when you’re sleeping, away, and actively at home. The thermostat will figure out how and when to strive for each target temperature.

If you plan to come home early, you can override the “away” temperature setting using an app on your smartphone. Likewise, you don’t have to get out of bed until the home is warm enough for you.

The Nest Learning Thermostat http://amzn.to/1Mjh1tx (about $224 on Amazon) is one of the pioneers and current leaders in the smart thermostat market. The latest Nest thermostat can sense when someone’s home, when the relative humidity changes, or when an oven is turned on, and adjust heating/cooling accordingly. Apps for Android, iOS, and Windows provide remote control and detailed information about energy use patterns.

In early 2014 Google paid $3.2 billion to acquire Nest (which was originally developed by former Apple employees) as part of the search giant’s foray into home automation. Already, Nest can serve as the intelligent controller for a number of other “smart” appliances, from lightbulbs to clothes dryers.

Honeywell’s Wi-Fi Smart Thermostat http://amzn.to/1k4QwkO (about $175 on Amazon) claims to learn your habits faster than “other brands.” It also sports a color-changing LCD screen that displays indoor/outdoor temperature, indoor humidity, date and time, and other info. It connects to the Internet via WiFi to enable remote control through an Android or iOS device. Currently, it does not integrate with other smart appliances.

The ecobee http://amzn.to/1OaRaeJ thermostat (about $240 on Amazon) is “for homes with more than one room.” In fact, it supports up to 32 remote, wireless sensors that can detect when you are in the bedroom, living room, kitchen, bathroom, etc., and adjust the temperature accordingly. It also learns your habits and can be controlled remotely. Depending on your heating/cooling system’s wiring, the ecobee and its remote sensors may require professional installation.

Some public utilities are offering subsidies of up to $200 to customers who install smart thermostats. Check with your utility to see which model(s) qualify for subsidies; in some cases, any WiFi-capable smart thermostat will qualify. Utilities are keen to help customers use less electricity and natural gas, because conservation postpones utilities’ need to invest in more power generation infrastructure.

Do you use a programmable or smart thermostat? Tell me about your experience with it. Post your comment or question below...