A thermostat controls the temperature of the home (or a section of the home) by turning on the furnace or boiler when the temperature falls below a pre-set level or by turning on a central air conditioner when the temperature rises above a pre-set level. Thermostats can also control other mechanical systems, such as humidifiers and air exchangers.
Types of Thermostats
There are three types of thermostats: manual, programmable, and smart models.
- Manual Thermostats
The traditional dial type of thermostat has worked for many years to control the heating and cooling of homes. It holds the set temperature and the home stays at that temperature until someone changes it. Often the settings are left at levels that are comfortable for people—even at night or when nobody is home—thus wasting energy. Manual thermostats may work best with electric resistance heat, radiant in-floor heat, heat pumps, and steam heat.
- Communicating Programmable (Smart) Thermostat
Communicating programmable thermostat thermostats allow users to change the temperature of the home based on the time of day and whether they are home or asleep. A digital programmable thermostat allows the settings to be changed or set at the thermostat itself, usually through a touch screen interface. Depending on the model, there may be up to four different modes available for each day: morning, day, evening, and night. The desired times for these modes can be selected, along with the desired temperature. Additionally, some models allow you to have different settings for weekdays and weekends. All programmable thermostats allow for overriding the programmed setting, to provide extra heating or cooling, for example, and most have a special setting for vacations. Additionally, most models can also control air exchangers, humidifiers, heat pumps, and other devices.
- Smart Thermostats
Smart thermostats operate essentially the same as programmable models, with one significant difference: they “learn” the preferences of occupants and adjust temperatures according to whether or not anyone is actually at home. Additionally, they are Wi-Fi enabled, allowing users to control settings through a smart phone app or computer. Monthly e-mail reports on usage and suggestions for energy savings are also included in most models. Finally, some are also linked with home security systems, providing remote monitoring and operation of many home functions.
Most programmable and smart thermostats are not complicated to install. Manuals and online videos can assist homeowners through the process, and usually the only tools required are screwdrivers. Sometimes, however, programmable or smart thermostats may require wiring that is different from manual thermostat wiring. Especially if you plan to control additional devices, the wires may not be in place to do so. If you need additional wiring for a new thermostat, contact an HVAC contractor or an electrician to run the wires.
Proper Thermostat Location
The location of your thermostat can affect its performance and efficiency. To operate properly, a thermostat must be on an interior wall away from direct sunlight, drafts, doorways, skylights, and windows. It should be located where natural room air currents—warm air rising, cool air sinking—occur. Furniture will block natural air movement, so do not place pieces in front of or below your thermostat. Also make sure your thermostat is conveniently located for programming.
Programming Your Thermostat
When programming your thermostat or providing initial settings for your smart thermostat, consider the schedules of everyone in the household, including work/school schedules and sleep times. Consistent times when no one is home or when people are sleeping are good opportunities to lower the settings in the winter and raise it in the summer. In order to save the most energy, start with settings that are lower in winter and higher in summer than what you are used to (66°-68° in winter and 74°-76° in summer). After a few days, evaluate your comfort, and adjust either the temperatures or the times when the temperatures change. Eventually, you should be able to balance comfort with maximum energy savings.
Why Upgrade Your Thermostat?
Many people are reluctant to invest in newer thermostats, primarily because of concerns about initial purchase costs. The cost of a programmable thermostat is between $20-$150, depending on features; a smart model may be more. But—if used properly—these models can actually save enough energy to offset their cost, sometimes in a year or so. But the key to their success is proper installation and use. A programmable thermostat that is not programmed (which some research shows may be up to 70% of households) will save no more energy than a manual thermostat. In those situations, a smart thermostat may actually save more energy, as it requires less attention to operate efficiently. Minnesota Power offers a $20 rebate on Communicating Thermostats that give customers access to set points and schedule from anywhere using a smart device (phone, tablet or computer).