Thermostats and Control Systems
Your thermostat can be the key to energy savings all year long. Annual savings of approximately ten percent can be achieved on your heating and cooling costs by adjusting your thermostat by ten to fifteen degrees for eight hour time stretches. This is easy to do without sacrificing comfort – just turn back your thermostat while sleeping or while you are out of the house for the day. A programmable thermostat or automatic setback thermostat can make the process of adjusting temperatures easy, requiring almost no effort on your part.
A programmable thermostat offers a lot of flexibility and allows you to adjust the times your heating and air conditioning systems operate, according to a pre-defined schedule. This saves money by not operating the equipment as much when you are sleeping or the house is unoccupied. Programmable thermostats can store multiple temperature settings according to a daily or weekly schedule. The programs allow you to set the day and time, to choose multiple temperature settings for different parts of the day and to specify how long to hold the temperature at a particular setting. The programs can also be manually overridden if you want to change the temperature for a specific length of time without affecting the remaining program parameters.
Thermostats and Control Systems
In the winter, you can save as much as one percent for each degree that you turn your thermostat down for a period of eight hours. The same strategy works in the summer with central air conditioning. The percentage of savings is greater when you live in a milder climate than when climate changes are more severe. By using a programmable thermostat instead of a manual one, it is easier to make the temperature changes on a regular basis. You can also avoid the discomfort of the increase or decrease in temperature when you're away or sleeping by setting the thermostat to restore your home to a more comfortable temperature right before you return home or awake. It may require a little trial and error to figure out the best timeframes for raising and lowering temperatures in order to maintain comfort while still conserving energy, but once you figure out what works for your home and your schedule you can easily conserve energy and save money with little to no discomfort or effort.
There has long been a misconception that by setting back your thermostat, you don't really benefit from much in energy savings because the furnace or air conditioning system has to work harder to warm or cool your home and restore it to a comfortable temperature. Through years of research it has been shown that this isn't true. The fuel needed to reheat a building to its original temperature is generally equal to the fuel that is saved as the temperature drops. The savings comes between the time that the temperature stabilizes at the lower temperature and the time until it needs to be reheated again. This means that the longer the time that the temperature is set back, the more energy you will save. This works for air conditioning as well.
Programmable thermostats are not recommended for use with certain types of heating systems. These limitations relate to heat pumps, electric resistance heating systems, and steam heating and radiant floor heating systems.
Maintaining a moderate setting is usually the most cost effective method of operating heat pumps. When they are in cooling mode, they operate like an air conditioner and turning up the thermostat will save energy and therefore money. But, when a heat pump is in heating mode, setting back the temperature can cause the system to operate inefficiently, which cancels any potential energy or money savings. There are, however, some companies that now offer specially designed programmable thermostats specifically for use with heat pumps that can result in energy and cost efficiency by setting back the thermostat.
Electric Resistance Heating Systems
These systems, such as electric baseboard heating, require thermostats that are capable of directly controlling 120-volt or 240-volt circuits. Only a few companies manufacture line-voltage programmable thermostats that can be used with these types of systems.
Steam Heating and Radiant Floor Heating Systems
Both of these systems typically have a low response time, so it is usually suggested that setting back temperatures not be done because it takes too long to restore a comfortable temperature. There are some manufacturers that now offer thermostats for these systems that track the performance of the system to determine how long in advance a temperature needs to begin to be restored in order to achieve a comfortable temperature at a specified time, so this overcomes some of the obstacles of using programmable thermostats with these types of systems.
There are a few different options available when choosing a programmable thermostat. Most programmable thermostats are either digital or electromechanical and some can be a mixture of both. Digital thermostats offer the most features, such as multiple temperature settings, overrides and even adjustments for daylight savings time, but are sometimes a bit difficult to program. Electromechanical systems are usually easier to program, using pegs or sliding bars, but do not offer as many options. Be sure to look for the ENERGY STAR® label when shopping for a programmable thermostat.
When programming a thermostat it is best to consider the schedules of everyone in the house. Determine sleep and wake times and the times that the house is unoccupied for long stretches of time. Then determine how long before you sleep or wake, or before you leave the house or arrive, you can adjust the temperature while still maintaining comfort. You may be able to adjust the temperature while you are still at home or awake without noticing a big difference in temperature. You can always override settings when you need to change the temperature because your schedule changes.
Another thing to think about when installing a programmable thermostat is that the location of the thermostat can affect its performance and efficiency. It is best to place thermostats away from direct sunlight, drafts, doorways, windows and skylights. You should read the manufacturer's instructions carefully to avoid ghost readings or unnecessary system cycling. It is also important to locate your thermostat in a place that is easily accessible and convenient for when you need to program the unit or override a programmed setting.
Using programmable thermostats can be an easy way to conserve energy and money all year long. With just a little bit of effort, you can reduce heating and cooling costs by about ten percent a year, simply by not wasting valuable heating and cooling energy while the residents of your home are sleeping or while the house is unoccupied.