What is it? How does it work?
The programmable thermostat is a device that controls the
heating/cooling system of your home. The programmable thermostat may
also be commonly known as a set back thermostat.
Automated Thermostat (Programmable Thermostat)
A thermostat
uses a feedback loop (indicated by the red arrows) to control a
room's temperature. The thermostat compares the desired room
temperature against the actual room temperature, then sends the
appropriate instructions to the furnace (in this case, the thermostat
instructs the furnace to turn on). By continually cycling through
this feedback loop, the actual temperature will eventually reach, and
then be maintained at, the desired temperature.
Microsoft
Illustration (excerpt from Microsoft)
A programmable thermostat operates on the same concept of a
conventional thermostat. It senses the temperature and turns the
heating/cooling system on and off to maintain a set temperature. It
also takes this process one step farther. More or less it has a small
computer inside it. In a way it is kind of like an alarm clock. You
set the clock on the unit so it knows what time of day it is. Then
you set the temperature(s) for a specific time frame. The furnace
will run to keep a certain temperature when you want it to. The
furnace will also not run or run less at periods when heating is not
necessary.
Custom programming features allow you to tailor your system to
meet your needs. For example, say you work from 9am. to 5pm. during
the week. You are home from only 6pm. to 8am.. With a congenital
thermostat you would have to set a certain temperature to keep 24
hours a day (unless you manually set back the thermostat). A
programmable thermostat can lower the temperature in the home when
you are not there (say from 9am. to 5pm.). You can also tell it to
start warming up the home before you get there. By the time you come
home the house is warm and you didn't heat it unnecessarily. The
beneficial factor here is the cost savings.
