Programmable Thermostats

When it comes to reducing your energy costs one of the simplest and most cost effective things most home owners can do is to replace their old thermostat with a new programmable thermostat.  The digital era has brought a host of new capabilities to thermostats which allow you much tighter control over how energy is used in your home. Programmable thermostats automatically adjust your home's temperature settings, allowing you to save energy while you're away or sleeping.

The new generation of thermostats have a number of specific advantages:

1. They are more convenient and accurate than manual thermostats and improve your home’s comfort
2. Contain no mercury
3. Save energy and save money on utility bills — when used properly, about $150/year
4.  Are better for the environment, since using less energy helps reduce greenhouse gas emissions associated with energy production

Choosing the Right Model

Costs for programmable thermostats can vary from around $40 to as high as $375 depending upon their features.  That is why it is important to understand what features you need before you shop.  The primary differentiator between most models is the number of programmable periods they provide.  The number of heating periods you may need depends upon the nature of your weekly schedule relative to energy consumption.

1. Seven day models are best if your daily schedule tends to change, say, if children are at home earlier on some days. They give you the most flexibility, and let you set different programs for different days – usually with four possible temperature periods per day.
2. Five plus Two day models use the same schedule every weekday, and another for weekends.
3. 5-1-1 models are best if you tend to keep one schedule Monday through Friday, and another schedule on Saturdays and Sundays.

There is still a lot of variability in thermostat prices so if you can get a seven day model for the same price as the others go with the seven day model because this will give you the most flexibility in the long run. A family's energy usage pattern can change a lot over time and these thermostats should last a long time. 

Features

Modern digital thermostats come with far more features then the old mercury switch thermostats most of us grew up with.  Most will include four default program periods per day, allowing you to save money by turning the thermostat down while you are away or sleeping.  The new thermostats are also more accurate than the older ones.  Most will be accurate +/- 2 degrees and so  keep the temperature at an even level, keeping you comfortable.

Programmable thermostats typically come with the following functions:

1. Digital, backlit displays
2. Touch pad screen programming
3. Voice and/or phone programming
4. Hold/Vacation features
5. Indicators which tell you when its time to change air filters
6. Indicators that signal malfunctioning of heating/cooling systems
7. Adaptive Recovery/ Smart Recovery features - control features that senses the amount of time it will take to reach the next set-point temperature, and reach desired temperatures by the set time

Programmable thermostats are becoming increasingly sophisticated.  One of the more interesting areas in which they have evolved has been the addition of wireless sensor capability.  By using wireless technology temperature sensors can be located in more locations both inside and outside your home to help optimize the sensitivity of your heating and cooling system. In addition, thermostats can be combined with wireless motion sensors to sense when people are in the home or building.  This type of technology has been used in advanced building control systems for years but is starting to become available for residential systems as well.  Sensor based systems are especially useful if your schedule is too erratic for a day of the week type of system.  Using sensors the heating or cooling system can turn on automatically only when someone is in the home regardless of the schedule. More advanced units may also provide these additional features:

1. Set Fahrenheit or Celsius metric
2. Program retention should there be a loss of power
3. Programmable blower control (separate from the furnace itself)
4. Air conditioning compressor delay
5. Built-in thermostat diagnostics
6. Display outdoor air temperature
7. Support for heat pumps
8. Lighted keypad

Getting the Most Savings Out of Your Thermostat

Like any appliance, how much energy and therefore money you can save depends upon how you use it.  Here are a few simple rules for getting the most out of yours:

1. Keep the temperature set at its energy savings set-points for long periods of time (at least eight hours), for example, during the day, when no one is at home, and through the night, after bedtime.
2. All thermostats let you temporarily make an area warmer or cooler, without erasing the pre-set programming. This override is cancelled automatically at the next program period. These features are nice but the trick is not to overuse them. You use more energy (and end up paying more on energy bills) if you consistently “hold” or over-ride the pre-programmed settings.
3. Units typically have 2 types of hold features: (a) hold/permanent/vacation; (b) temporary. Avoid using the hold/permanent/vacation feature to manage day to day temperature settings. “Hold” or “vacation” features are best when you're planning be away for an extended period. Set this feature at a constant, efficient temperature (i.e. several degrees warmer temperature in summer, several degrees cooler during winter), when going away for the weekend or on vacation. You'll waste energy and money if you leave the “hold” feature at the comfort setting while you're away.
4. Cranking your unit up to 90 degrees or down to 40 degrees, for example, will not heat or cool your house any faster. Most thermostats begin to heat or cool at a programmed time, to reach set-point temperatures sometime thereafter. Units with adaptive, “smart,” or “intelligent” recovery features are an exception to this rule — they reach desired temperatures by the set time, since they use formulas that are based on your historical use.
5. Install your 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). Many homes use just one thermostat to control the whole house. If your home has multiple heating or cooling zones, you'll need a programmed setback thermostat for each zone to maximize comfort, convenience and energy savings throughout the house.
6. Don't forget to change the batteries each year. Some units indicate when batteries must be changed.

Energy Star Ratings

Programmable thermostats are now rated as part of the Energy Star program.  Programmable thermostats earn the energy star rating by meeting strict energy efficiency guidelines set by the government. These units save energy by offering 4 convenient, pre-programmed temperature settings — settings that try to anticipate when it's convenient for you to scale back on heating or cooling. If you are like many homeowners and work outside the home during the day and have a different schedule on the weekend, a programmable thermostat can offer many benefits, and the return on your investment is usually within 1 year.  The table below contains the current ratings:

Energy Star Ratings for Programmable Thermostats