Hot weather affects our comfortHigh air conditioning costs will result from the very hot weather we are having in Indianapolis and all of central Indiana. How high will the AC bill be? Expect double or triple the cost to cool your home. Here’s why the hot weather will have such an impact on your cooling costs.

You normally cool your home a very “easy” 10 to 15 degrees difference from the outside temperature. For example if it’s 75 in your air conditioned home and 88 degrees outside, you have cooled your home 13 degrees. (A normal “hot” summer day in Indiana would be about 88 degrees.) So, when it’s 100 degrees outside, you have nearly doubled the air conditioning load! But wait, it get’s worse for some people.

As a result of (very helpful) conservation efforts by several sources within our community, we actually use less air conditioning than we did in the past during normal summer conditions. Some of us cool our homes to a higher temperature (ex., 77 instead of 75) and others simply reserve air conditioner use for the hottest days only. What does extremely hot weather do to the air conditioning portion of our electric bill? Maybe triple! Since our “new normal” air conditioning habits have reduced our electric bill to a new low, it is not uncommon for the extreme heat to be three times cost of the normal weather, conservative AC cost.

Here is more information about the extreme heat and air conditioning:

  1. Air conditioners are less efficient in very hot weather. Think about it. The outside AC unit is trying to get rid of the heat from your home by cooling the air fins on your outside unit. It is very difficult to cool this appliance when it is sitting in 100 degree heat. Is it also on the west side of your home? OUCH! This can further decrease the efficiency of your system.
  2. Humidity loads are higher in times of very hot weather. This is a complicated topic and deserves more explanation than this, but for now, know that the extremely hot air can hold much more humidity than normal summer air. So if it can, it frequently does! Without complicating this information too much, know that 100 degree air at 40 percent relative humidity has about three times the moisture load than 88 degree air at 40 percent relative humidity. Why is humidity a load on your air conditioner? Your AC removes moisture first and cools the home second with whatever cooling it has left. If you have lots of outside humid air leaking into your home, you’re going to see this in your cooling costs. Seal up your home and limit door openings in the extreme heat.
  3. Do you have ducts in your attic? Have you been in your attic when the weather person says it’s 100 degrees outside? Extreme heat and sunny conditions can heat your attic to over 130 degrees. (Sounds like I am exagerating but this one is an easy one for you to experience for yourself. Let me know…) Those ducts in the attic should be very well insulated from the attic air. Also, experiment with your AC fan setting. Some homes with ducts in the attic will be better off without circulating the fan continuously. When the AC is off, why circulate your 75 degree indoor air into a duct system that is in a 130 degree space?

Finally, what should you do if your air conditioning bills get too high? Call us. Yes we are extremely busy with all the hot weather but it has to break some day. We can look over your system and see what adjustments are needed to increase your air conditioning efficiency and reduce your AC costs.