Happy New Year!  I begin 2010 with a slightly failed experiment…  I have been doing a little research on the energy savings achieved by using the setback feature built into Energy Star thermostats.  While some studies show little to no benefit to lowering the temperature of the house at night, and while unoccupied, others have shown a savings of up to 30% by dropping the temperature set point by 10 degrees for 8 hours per day.  Last night, while waiting for the ball to drop in New York’s Times Square, I decided to try a little experiment of my own.  I turned the thermostat setback feature on and lowered the overnight minimum temperature to 60F (from 69F).

Our Honeywell thermostats have a feature called Adaptive Intelligent Recovery (AIR).  This feature allows the thermostat to determine how much heating time is required for the house to reach the set temperature at the specified time.  For instance, I set the thermostats to allow the house to cool (to a minimum of 60F) while we are sleeping at night, but come 6:00 AM, I want the house to be at a comfortable 69F – even if the temperature dropped all the way to 60F over night.  After a few days, the thermostat is able to calculate how long the heat needs to run in order to bring the house up to the set temperature.  It begins warming the house early enough to reach the set point at the specified time.  AIR is NOT a feature of all thermostats, however ALL Energy Star rated thermostats have the setback feature.

In any case, my first night of experimenting more or less failed because one of our heat pumps locked out.  Sand from the well clogged the filter.  It reduced the water flow so much that the heat pump could not function properly.  The unit locked out to prevent freeze damage.  I am not sure how this will affect the AIR feature, but I will let it work for a few days and see what happens.  The first interesting thing of note: the 1st floor temperature was 65F when I got up, and the 2nd floor was at its set point of 68F.  The second interesting thing of note: my wife got out of bed in the middle of the night and felt 65F was too cold.  Energy savings aside, this experiment may never get off the ground. :-)

On a slightly different note, I have been looking for a way to prove how energy efficient this house is.  Sure, I can say it is, but without hard data beyond our utility bills, I have no real proof.  Our energy bills have actually been low enough that our next door neighbor believes we live life with frigid indoor temperatures and no lights on!  While this could not be further from the truth, we have no proof.

I have been speaking with Onset Computers (http://www.onsetcomp.com/) regarding a partnership.  In order to be beneficial to both parties, the goals would be multi-fold.  The initial goal will be to prove how efficient this house is, and generate some publicity on this fact alone.  This will help Onset get its name out there, and further my goal of getting information out to others so they may build houses like this one.  Second, we will use the data obtained by the Onset instruments to improve energy efficiency in any way possible.  It is my sincere hope that we can save enough money over time to justify the cost of the instruments.  If we can accomplish this goal, and publicize the results, it will truly be a win-win for both parties.  We’ll personally enjoy even greater savings, and demonstrate that data collected by Onset’s instruments can help increase energy savings (of even the most energy efficient structures) beyond the cost of the instrumentation.

Wishing you all a happy, healthy New Year,
Ed