Should You Turn Down Your AC While at Work?

As the summer approaches, our technicians are out on daily annual maintenance appointments and repairs.  If you were to ask any one of them a highlight of their day, they would probably answer something to the tune of helping our customers understand their air conditioners.  Some typical questions asked are, “Is my air conditioner energy efficient?” or “Why is one room cooler than the next?” But  most commonly, the technicians are asked, “Should I turn down my air conditioner while at work?” Of course, there are a few different schools of thought regarding air conditioner usage with a vacant house and they range from breaking the basic laws of physics to simply saving money on your energy bill.  But, for the sake of this blog, I am going to give a quick and simple answer to the question of, “Should you turn down your AC while at work?”

Air conditioner usage is a two-way street between the unit itself and the homeowners it belongs to.  It is completely unrealistic to think that your air conditioner unit will be energy efficient, save you money and keep your house cool if you don’t apply good reasoning to its use.   For example, if your house is too hot and you set the temperature excessively low to cool the house faster, you are wrong.  In fact, the air conditioner cools at the same rate as if you had set it at a normal temperature.  The difference is, the excessively low-temperature setting forces the air conditioner unit to work non-stop and I can guarantee you cost you more in the long run.

Let’s discuss AC use while at work.  Should you turn it off?  Should you turn it down?  What’s the answer?   The reality of an eight hour work day is this:  allowing your air conditioner to constantly run in an empty house is both expensive and inefficient.  On the flip side, turning your air conditioner completely off is not an efficient trade-off either.  Especially if the temperature of your home rises to 80+ degrees while you are away.  So, should you turn your AC down while at work?  Yes!  You should.  The bottom line, if you do not have a programmable thermostat, you can manually increase the temperature by 5 degrees when you leave and decrease it to your desired temperature when you return.  This change will only take your air conditioner around 30 minutes to adjust and will ensure that your unit does not run throughout the entire work day.   If you have a programmable thermostat, program the temperature setting to reflect when the house is occupied vs empty.

Here are a few extra ways to save both energy and money this summer:

  • Purchase or learn how to use your programmable thermostat.  When used correctly, it has been estimated by Energy Star that it will save you approximately $180 every year in energy costs (energystar.gov.)  Besides money and energy savings, programmable thermostats will ensure that your home is always comfortable.
  • Use a ceiling fan. Ceiling fans are not meant to cool rooms, instead, they help circulate and distribute air, cooling the people in the room.  During summer months, turn blades to run counter-clockwise to push cool air down.
  •  Keep the heat out. Heat will attempt to let itself into your home via open doors, windows, and subtle leaks.  Consider applying a window film to act as a solar heat barrier, keep blinds and doors closed if possible and apply an outdoor rated caulk to window and door seals as needed.
  • Insulation. This one is not a quick fix and will need to be budgeted for, but increasing insulation in your attic etc. will help keep heat out in the summer and heat in the winter.

There is a lot of extra reading here for the simple question of, “Should you turn down your air conditioner while at work,” and remember that the simple answer is, yes.  By increasing the temperature by 1-5 degrees while the house is empty, you save both money and energy.