What does it cost to run Central Air Conditioning ?

By far the most common question we get from customers who are considering installing Central Air Conditioning is what it will cost to operate it in the Edmonton Area.

The formula for calculating the exact cost can be fairly intimidating but the following Laymans rule of thumb will provide you a budgetary amount that will only be slightly higher or slightly lower once the bills start coming in.


Determine the Amperage of your unit.  For a 13 SEER unit which is the most common in Edmonton  a 2 ton unit is typically 17 amps, a 3 ton unit 19 amps and a 4 ton unit 21 amps


Calculate the wattage used by your unit. All Central Air Units are wired to run on 240 volts so to calculate your wattage multiply the amps by 240.  Eg; for a two ton unit it would be 17 x 240 = 4080 watts


Electricity is billed by KWh, to determine the KWh for the size of your unit divide the wattage used by 1000. In this case  4080 / 1000 = 4.08 KWH


Multiply your cost per KWH, approximately 12.7 cents in the Edmonton area by your KWH. In the case of this 2 ton unit  12.7 x 4.08 =  51.81 cents per hour would be your approximate cost of operation.


If your unit ran for 24 hours a day the cost to operate it would be $12.43 per day or 375.00 per month.


A properly sized air conditioner does not run 24 hours a day, not even in 40 degree heat without any drop in temperature at night. As a general rule and assuming you set your thermostat to Cool to 21 degrees Celsius you can determine how many hours your unit will run during the day by using the following factors:


Outside temperature                     Multiplier

40 degrees                                          .8

36 degrees                                          .4

32 degrees                                          .3

26 degrees                                          .25

24 degrees                                          .20


Multiply your 24 hours cost per month by the above factors to determine your approximate monthly cost based on weather patterns in Edmonton. In this case, the two ton unit operating with average outdoor temperatures of 26 degrees would  be $375.00 x .25 = $93.75 per month.

Click on Return to news at the bottom of page and see our post  "save on your AC utility  bills" from June of 2014 for suggestions on how to reduce your monthly AC bill while still keeping your home comfortably cool

Posted Jun 11, 2015

Leave A Comment

char said on August 9, 2015

Thank you very much for such a complete breakdown... Very well done!