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Setback Payback Featured on Jan 02, 2009

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Challenge Details

There was a time when saying the word “program” in reference to a home appliance sent shivers of terror through helpless consumers. “Programmable” was something people said about VCRs and we all know how that worked. In our houses, unless we intervened, the VCR was constantly blinking 12:00 and was never used to record anything if it involved interacting with the menu. One time, my father missed taping a college basketball game and he literally cried. It was the VCR’s fault, he thought. You can’t trust anything “programmable” because the darned devices have their own agendas. Luckily, decades pass and our paranoia eases somewhat. Today, my father can program a DVR, a universal remote, and his new programmable thermostat. Civilization advances.

This Featured Challenge is based on suggestions made by karens and melaniestair. To date, their suggestions have received 20 positive votes each in our Challenge Workshop. Karens has taken 54 Challenges so far and is a member of the Beyond Green team. Melaniestair has taken a whopping 150 Challenges so far and is a member of OTEP’s Green Team, still in first place in the All Teams and General League categories on our 30-Day Leaderboard.

The Carbon Connection
Keeping your home warm requires a lot of energy. Furnaces and boilers either burn natural gas or fuel oil to heat the air or water used to heat your home. Turning your thermostat down means your furnace or boiler runs less and burns less fuel. The less fuel oil or natural gas you burn, the fewer pounds of carbon dioxide get released into the air. A programmable thermostat is an electronic device that turns your thermostat down for you. It “sets back” the temperature in your home when you aren’t at home during the day and at night when you’re asleep. It does the job automatically, without you having to think about it. Used correctly, this saves the environment hundreds of extra pounds of carbon dioxide.

Using a programmable thermostat can also save you cold, hard cash. According to US Department of Energy’s Energy Information Administration (EIA), the average U.S. household will spend $1,137 to stay warm this winter. That is a 15% increase over last winter’s $986 average total heating bill. The largest increases will be in households using heating oil and natural gas. The EIA says you can lower your home heating costs by about 5 percent for every 1 degree lower you set the thermostat. Proper use of a programmable thermostat can lower your home heating costs by 30% a month, which is about $40 a month at current energy prices. Not bad for something you can set and forget.

Getting It Done
Here are a few suggestions about installing and using a programmable thermostat to lower the costs and lower carbon emissions from home heating:

• This Challenge was written for those of you who have furnaces burning either natural gas or fuel oil. If you use steam heat, you cannot use a programmable thermostat. If you use electric baseboard heating, radiant floor heating, or if you have a heat pump, you may be able to use programmable thermostats, but not the kind typically found on hardware store shelves. You will need to consult a heating professional. If you do have a furnace that burns either fuel oil or natural gas, read on.
• The first thing you need to do is choose the right programmable thermostat to meet your needs. There are many models and manufacturers to choose from. Most of them will control both your heating and cooling systems. In general, programmable thermostats come in three basic types. Some thermostats (the 5 + 2 type) allow you to have one program for the weekdays and then a second program that applies to both days of the weekends. Others (the 5 + 1+ 1 type) allow you to have different programs for Saturday and Sunday. And then there are 7 day thermostats that allow you to have a different setting for every day of the week. Choose the type of thermostat depending on how regular your schedule happens to be.
• After you’ve chosen the basic type of programmable thermostat, then you can start looking at some of the specific extra features found on different models. Some thermostats have touch screens or backlit display panels. Some have sensors that monitor your air filters. Some try to learn how quickly your house heats up or cools off and then adjusts when it turns the furnace on. Depending on the feature set, a programmable thermostat should cost you between $25 and $90.
• Next, you need to install the programmable thermostat. Usually, this involves replacing an already-existing manual thermostat. For good advice on how to install your new thermostat yourself, see the how-to videos at This Old House and Lowes. If, after you’ve watched those videos, you feel this project may be too much for you, rest assured that a heating professional or an electrician will be glad to help you out. Don’t worry. The money you save by using less energy will not only pay for the thermostat itself, but pay for the installation as well.
• Now that your thermostat is installed, it’s time to program it to work with your schedule. Programmable thermostats typically come with 4 time setting periods per day. Two of these are “normal” temperature settings. One normal setting is for when you wake up in the morning before you go to work or school; the other normal setting is for when you come home from work or school in the late afternoon or early evening. The other two time settings are “setback” settings — time periods when the temperature is set back or turned down 8 degrees. One setback period is for the time when you are away from home, such as the time you are at home or work during a weekday. The other setback period is when you are in bed at night, tucked away under warm blankets. When you program your thermostat, you will need to adjust the time when these 4 time periods begin and end so that it matches your own schedule, both for weekdays and weekends.
• Finally, don’t get in the thermostat’s way. Let it do its job. Don’t shorten the setback periods. Try to keep those weekdays such that the temperature in your house is set back 16 out of 24 hours. (You’re either not there or you’re asleep. It isn’t as much time as it sounds like!) And no using the Hold button to override the programming all the time. You won’t be saving money or carbon if you keep the temperature at the higher temperature for longer periods of time.

Already installed a programmable thermostat? What brand do you use? How well does it work? Share your thoughts, stories, and suggestions with your fellow Rallyers in the Challenge forum section below.

Rules of the Challenge
This Challenge asks that you do two things: 1) install a programmable thermostat if you don’t already have one; and 2) use the programmable thermostat correctly so that you set back the temperature in your home at night when you’re asleep and during the weekdays when you are at work or at school. By using a programmable thermostat to control your home heating for the next month, you will save 248.7 lbs of CO2. This Challenge is repeatable. You should repeat the Challenge each month that you use heating after you start using your programmable thermostat.

Learn More
Energy Star: Programmable Thermostats
This Old House: How to Install a Programmable Thermostat
US Dept. of Energy: Your Home, Thermostats and Control Systems

See the Math
Rather than start from scratch this time, we’ve used the Programmable Thermostat Savings Calculator provided by Energy Star. Here are the numbers or assumptions we’ve plugged in or changed to get our Challenge payoff:

• The amount of energy you need to keep your home warm and toasty depends a lot on where you live and how many days a year you need to turn on the furnace. For example, a home in Connecticut needs to use its furnace 6 times as many days per year as a home in Georgia. For the purposes of our calculations, we’ve chosen St. Louis, Missouri as our average American-heating-consumer city. Some of you live in regions where you need to use your furnace more; some of you live where you need to use your furnace less.
• Energy Star certified programmable thermostats come preprogrammed with a 70 degree normal temperature setting and a 62 degree setback temperature. The calculator assumes that you will set back your daytime temperatures on the weekend as well as the weekdays. We kept the temperatures the same, but took out the weekend daytime setbacks.
• We also changed the fuel costs to match current national averages. We used $2.98 per gallon of fuel oil and $20 per thousand cubic feet of natural gas. (That’s equal to about $2 per therm.)
• Setting the calculator with the above settings, we see that the average dollar savings from using the programmable thermostat to set back temperatures is close to $200 for the heating season. (Actual numbers range from $190 for a gas furnace to $212 for an oil-burning boiler.) The heating season is assumed to be 5 months long. So your savings works out to $40 per month average for the season.
• The amount of carbon dioxide released when you burn fuel oil is different than the amount released when your burn natural gas. The calculator uses the following EPA conversions: 161.27 lbs CO2 per million BTUs (MBTU) from burning fuel oil and 116.97 lbs CO2 per MBTU from burning natural gas.
• Again with the above settings, the calculator shows that you will reduce your energy expenditure by 10 MBTUs per heating season. That number does not depend on whether you are burning natural gas or fuel oil.
• Multiply 10 MBTU by each conversion factor to find the amount of CO2 not released per heating season by homes using the two different fuels. That gives us 1612.7 lbs CO2 for homes burning fuel oil and 1169.7 for homes burning natural gas.
• Remember that we are calling our average heating season 5 months long. Divide each number by 5 to get CO2 savings per month: 322.5 lbs CO2 saved per month for fuel oil homes and 233.9 lbs CO2 saved per month for natural gas homes.
• There are 5 times as many homes using natural gas for their heating as there are homes using fuel oil. To get our final carbon savings, we did a weighted average of the CO2 savings for homes using fuel oil and homes using natural gas. That gives us 248.7 lbs CO2 saved per month by using a programmable thermostat.
• Finally, we see that the Energy Star calculator assumes that you are starting from having your home at a constant temperature of 70 degrees for the entire heating season. And very few of you probably do that. So for many of you, this Challenge is to improve your home heating consciousness. To allow for that and to allow for other variations in heating behavior (e.g., working from home one day a week and not wanting to freeze, etc.), we are taking 20% off the results for the Challenge. That gives us a final result of 200 lbs CO2 and $32 saved per month by using a programmable thermostat.

Think of it this way. If no one is home on weekday mornings and afternoons, there’s no reason to heat the house as if someone is there. Set back the heat! The plants won’t mind and the cats have fur. And at night, throw an extra quilt on the bed and bundle up. Set back the heat; save yourself some money; and save a lot of carbon this heating season. Keep toasty, Rallyers!

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