Example: Trane Thermostat

What's the most practical way to save money on electricity and gas with technology?   Focus on reducing your expenses related to the largest percentage expenditures on your utility bills- lighting and climate (heating and cooling).  What can you do around cutting the cost of heating and cooling your house?

We recommend doing non-technology related things as well to save money, such as, replacing drafty windows and doors, insulating where needed and using
Energy Star rated appliances.  Aside from these, a programmable thermostat is the best option.  Everyone should be using one.  It can save on average $180 per year (about 15%).  It does this by putting your HVAC system on a schedule that sets back the temperature when you're not home.  Simple. 

The trick to the savings is consistency.  You have to maintain the schedule of set backs.  When you don't, you save less.  The schedule is designed around a working/ school going family where there's no one home for a period of time each day.

The thermostat becomes a 'set and forget' device.  It does its thing on a schedule and saves you money.  You shouldn't be fiddling with the schedule much at all once set- there's no reason to and it will cut your savings.  So what's a communicating programmable thermostat?

As discussed, a programmable thermostat is the device that saves you the money.  Getting one that integrates with other devices in your home by communicating with them and can be monitored and accessed from outside your home via an iPhone, for instance, is a perk.  Necessary?  No.  Does it add comfort and convenience?  Yes.

So what's the benefit of communicating with the thermostat?  There are several benefits.  First, although the thermostat works best on a schedule, sometimes you need to make 'emergency' changes to it when you're not home (e.g. on vacation and forgot to turn the system off).  You can use a Web browser or smartphone to access your thermostat and make adjustments to it.  Second, integrating climate control with your security system makes incredible sense.  In the event of a fire, the security system can turn off the heating and cooling system.  It can also control the thermostat schedules when either Armed-Away or Armed-Stay.  Third, the thermostat can send you alerts when changes to the schedule are made or something out of the ordinary happens, like the temperature in your house is outside of a normal range.

Some helpful information from Energy Star :

Rules of Thumb for Proper Use:

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. 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
   to 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,
   including ENERGY STAR qualified units, begin to hear or cool at a set
   time, to reach setpoint temperatures sometime thereafter. Units with
   adaptive
   (smart/intelligent) recovery features are an exception to this rule —
   Adaptive recovery units are constantly calculating the amount of time
   required to heat or cool the house, so that it reaches that temperature
   when the homeowner programmed it. By “examining” the performance of the
   past few days the thermostat can keep track of the seasons. In this way,
   your house is always at the comfort levels when occupied, but saving
   the most energy when unoccupied.
5. 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. If your programmable thermostat runs on batteries, don't forget to
   change the batteries each year. Some units will indicate when batteries
   must be changed.