Thermostats can be very simple. They are at their core On-Off switches for heating and cooling equipment, designed to respond to temperature changes…
But modern programmable models can also be quite sophisticated, with multiple features. Many of these features can be important for ease of use or convenience, though irrelevant for energy savings.
Features that Can Be important for Energy Savings
A simple manual thermostat can provide reasonable energy savings, if you are willing to actively manage it. But in many cases a programmable thermostat is a better choice. Automatic adjustment of the settings is more than just a mere convenience.
When buying, select a programmable thermostat with at least two programs: one for weekends and one for weekdays.
Seven-day thermostats allow you to set different programs for each day of the week, and if they fit with your lifestyle and schedules go head. The difference in price when compared to other simpler programmable thermostats is not significant, and they are not necessarily harder to program…
Also prefer a thermostat with at least four temperature settings, to program the periods while you are at home, away from home, asleep…
Also prefer a thermostat with a "hold"/override function; most modern digital thermostats allow users to temporary override the current setpoint temperature for a certain period of time; they also include a function to "hold" the current temperature, which will be maintained until you cancel the hold or another programmed event occurs and the normal program is resumed.
Finally, prefer thermostats with precise temperature control (+/-1ºF/0,5ºC); new digital thermostats provide higher levels of accuracy than typical mechanical units.
Other special features
Other features vary among models and manufacturers. They may not be important for energy savings, but may be helpful. Here is a small list:
- Screen Controls and Backlit Display Panel: digital thermostats can have large backlit displays to make reading easier in low-light environments. Touch-sensitive controls may also be helpful… Modern models are moving to touch-screen menus instead of buttons and knobs.
- Indicator Lights, to signal malfunction of the heating and cooling equipment, or to let you know when the battery is low or when to replace a filter….
- Remote Controls, to setback and recover thermostat control from anywhere in the home.
- Keyboard Lock: to prevent children or other people from altering the settings.
- Vacation Mode: to temporarily override the settings, or to introduce new settings for energy savings…
- Full memory save: to restore the settings.
- Adjustable cycle and auto changeover switch: to prevent on-off cycling of the heating and cooling equipment, and to allow the equipment to automatically switch between the heating and the cooling mode - a handy feature in areas with great thermal amplitudes (hot days, cool nights).
- Phone and voice programming.
Heat pumps require special programmable thermostats; and though they are now relatively common, and using sophisticated algorithms to optimize results, they may not be effective enough in the heat pump heating mode.
Steam heating and radiant floor heating systems, like electric baseboard heating systems and electric resistance systems in general, also require special thermostats, and only a few manufacturers produce them...
Check for compatibility first, and be cautious: the slow response time of radiant and steam heating systems can make thermostats very ineffective.