Programmable Thermostats

Programmable thermostats allow you to set household temperature for specific periods throughout the day and night.  As a general rule, you can save two per cent on the space-heating portion of your bill for every 1°C you consistently turn down the thermostat over the heating period.

For example, if you use 100 gigajoules (GJ) of natural gas each year for home heating and lower the temperature setting from 21°C to 17°C for approximately eight hours, then you will save you about eight GJ a year.

Many people share the common misconception that a furnace has to work harder than normal to warm the space back to a comfortable temperature after it’s been set back, resulting in little or no savings. Years of research and numerous studies have dispelled this myth. The fuel required to reheat a home to a comfortable temperature is roughly equal to the fuel saved when the thermostat is set back to the lower temperature.  Fuel savings occur between the time the temperature stabilizes at the lower level and the next time heat is required. The longer your house remains at the lower temperature, the more energy you save. 

Installing a programmable thermostat has numerous benefits, many of which perform one or more of the following energy-control functions:

• store and repeat multiple daily settings, which can be manually overridden without affecting the rest of the daily or weekly program
  
  
• store six or more temperature settings a day
  
  
• adjust heating turn-on times as the outside temperature changes

Programmable thermostats can be found at most home improvement stores and outlets that sell heating equipment.

Types available:

• Electromechanical (EM) - typically the easiest to operate, having manual controls such as movable tabs which set a rotary timer, as well as sliding levers for night and day temperature settings
  
  
• Digital - identified by their LED or LCD digital readout and data-entry pads or buttons
  
  
• Hybrid - combined technology of digital controls with manual slides and knobs, simplifying use and maintaining flexibility
  
  
• Occupancy - maintain the setback temperature until someone presses a button to call for heat, and this type does not rely on the time of day
  
  
• Light Sensing - rely on light-levels set by the owner to activate the heating system.

When lighting is reduced, a photocell inside the thermostat senses unoccupied conditions and allows temperatures to fall below the occupied temperature setting.

Here are some questions to ask before buying a thermostat.

• Does the thermostat have an Energy Star rating? These products meet strict energy efficiency guidelines.
  
  
• Is the thermostat compatible with the electrical wiring in your current thermostat?
  
  
• Are the programming instructions easy to understand and remember? Will you have to consult the instruction manual every time you want to change the setback times?
  
  
• Are you able to install the thermostat yourself or should you hire a contractor?
  
  
• Does the unit’s clock draw its power from the heating system’s low voltage electrical control circuit instead of a battery? If so, is the clock disrupted when the furnace cycles on and off?
  
  
• How precise is the thermostat?

 When installing any thermostat, be sure to place or position the device where it won’t be affected by heat and draft sources such as direct sunlight, hot-air ducts, appliances, stairwells and exterior doors.