Cooperative Extension Energy Saving ProgramHome Energy Savings
  
 
 
Thermostats

Lowering your thermostat really does save energy - a LOT of energy.  It is less expensive to reheat a cooler house than it is to keep the heat at a higher temperature 24 hours a day. The basic rule of thumb is for each degree you lower your thermostat for a 24 hour period you will save 3% of your total energy usage during that 24 hours. So if you permanently set your thermostat back one degree (for the entire winter) you will save 3% on your heating energy bill. Set it back 5 degrees and you will save 15%.  In Central NY that's like saving $225!

If you find it too cold to set your thermostat back 5 or 10 degrees when you are awake in your house you can still save a lot by setting it back while you sleep, or setting it back while you are out of your home. For each 8 hour period you reduce the temperature you will save one percent. So if you reduce your thermostat setting every night by 5 degrees while you are sleeping you will save 5% over the course of the heating season. 

The "3% rule of thumb" doesn't hold when the thermostat is set very low. As the temperature of the house gets closer to the outside temperature the savings from lowering the thermostat one more degree gets less and less. So you can't expect to save 3% for each degree of reduction when your thermostat is already set at 60 or lower. There will be savings but the percentage savings will be lower.

Caution: You can save more by lowering the thermostat below 60 degrees but be careful. Rooms that are farthest from the thermostat and have outside walls may be considerably colder than the room in which the thermostat is located and water pipes in those rooms could be at risk of freezing if you set your thermostat too low. And drywall has a tendency to crack if rooms are too cold so check with knowledgeable people before setting your thermostat below 60 degrees.

What you can do:

  1. Lower the thermostat: For each one degree of reduction for an 8-hour period you will save 1% of your fuel use for that day. Keep that 1 degree reduction during that 8 hour period every day and you will save 1% on your annual fuel bill. If you lower the thermostat by 15 degrees for an 8-hour period you will reduce fuel consumption by 15%.
  2. Install a programmable thermostat: Raising and lowering the thermostat manually every day is a very low-cost way of saving a LOT of money. But you may forget to lower the temperature before heading off to work and then you’ve lost that opportunity to save that day. Or you may get tired of waking up to a very cold house or returning from work to a cold house. A programmable thermostat is a low-cost alternative that automatically sets back the thermostat, or raises the temperature setting on the thermostat when YOU program it to do so. So you can wake up in the morning to a warm house, and you can leave for work without worrying about setting the thermostat back.

Savings:

For each degree of setback for an 8 hour period you can save 1% of the fuel usage during the 24 hour period. If you set it back every day you would save 1% of your entire fuel bill that winter. One percent is about 15 dollars. Set it back 10 degrees for an 8 hour period every day of the heating season and save 150 dollars!

Installation of Programmable Thermostats
For starters, install your programmable thermostat unit on an interior wall, away from heating or cooling vents and other sources of heat or drafts (doorways, windows, skylights, direct sunlight or bright lamps)

Remember: Read all instructions and proceed carefully! Programmable thermostats are a low voltage wiring installation and involve anywhere from 2–10 wires, depending on your type of heating and cooling system. However, you should shut down your electricity during any replacement. The previous attachment points will reconnect your new unit.

If the job requires more than just a replacement, call your certified HVAC professional to ensure proper installation, as well as operation of your heating and cooling system. It's a good idea to upgrade an old manual thermostat to a programmable unit if you're replacing a CAC or heating system, given that programmable thermostats are far more accurate and will maximize the efficiency of your new system. Heat pumps may require a special unit to maximize energy savings year-round. Talk to your retailer or HVAC contractor before selecting the thermostat.

Also, if you're replacing a manual thermostat that has a mercury switch, be careful not to break the tube that holds this toxic substance. Contact your local recycling/hazardous materials center, or the manufacturer of your new thermostat, for advice on proper disposal.


 

How-To Guides

Videos:


How to replace a thermostat
(2:57 minutes, WMV video, 2.87 MB)


How to set your thermostat

(2:50 minutes, WMV video, 6.64 MB)


Estimating savings from setting back your thermostat

(45 seconds, WMV video, 4.67 MB)


Estimating savings 2

(45 seconds, WMV video, 4.28 MB)


Choosing the right thermostat
(2:30 minutes, WMV video, 6 MB)