General Thermostat Operation
You can easily save energy in the winter by setting
the thermostat to 68?F (20?C) when you're at home
and awake, and lowering it when you're asleep or
strategy is effective and inexpensive if you are willing to adjust the thermostat
by hand and wake up in a chilly house. In the summer, you can follow the same
strategy with central air conditioning, too, by keeping your house warmer than
normal when you are away, and lowering the thermostat setting to 78?F (26?C)
only when you are at home and need cooling.
A common misconception associated
with thermostats is that a furnace works harder than normal to warm the space
back to a comfortable temperature after the thermostat has been set back, resulting
in little or no savings. This misconception has been dispelled by years of research
and numerous studies. The fuel required to reheat a building to a comfortable
temperature is roughly equal to the fuel saved as the building drops to the lower
temperature. You save fuel between the time that the temperature stabilizes at
the lower level and the next time heat is needed. So, the longer your house remains
at the lower temperature, the more energy you save.
Another misconception is that the higher you raise a thermostat, the more heat
the furnace will put out, or that the house will warm up faster if the thermostat
is raised higher. Furnaces put out the same amount of heat no matter how high
the thermostat is set--the variable is how long it must stay on to reach the
In the winter, significant savings can be obtained by manually or automatically
reducing your thermostat's temperature setting for as little as four hours per
day. These savings can be attributed to a building's heat loss in the winter,
which depends greatly on the difference between the inside and outside temperatures.
For example, if you set the temperature back on your thermostat for an entire
night, your energy savings will be substantial. By turning your thermostat back
10? to 15? for 8 hours, you can save about 5% to 15% a year on your heating bill--a
savings of as much as 1% for each degree if the setback period is eight hours
long. The percentage of savings from setback is greater for buildings in milder
climates than for those in more severe climates. In the summer, you can achieve
similar savings by keeping the indoor temperature a bit higher when you're away
than you do when you're at home.
But there is a certain amount of inconvenience that results from manually controlling
the temperature on your thermostat. This includes waking up in a cooler than
normal house in the winter and possibly forgetting to adjust the thermostat (during
any season) when you leave the house or go to bed.