Overspend Calculator

When replacing your heating or cooling system, the ability to compare annual costs between your current system and all possibilities can assist in the decision making. By comparing your current unit to the unit being considered, using these formulas it is easy to figure out the amount you will be saving annually. If you have any issues, please email Kim for assistance.

**When finding BTU for an Air Conditioner or a Heat Pump, simply multiply the tons of the unit by 12,000.

Air Conditioner:

Cost of Operation = (718) * (AC BTU/SEER) * (Cost per KW/1000)

Example
15 SEER 2.5 Ton AC @ .06/KW
Cost =718*(30000/15)*(.06/1000)
=718*2000*.00006
=86.16

So a 15 SEER 2.5 Ton AC would cost $86.16 to run annually.

Air Source Heat Pump:

Cost of Operation= ((BTU/SEER) * (Cost per KW/1000) / .85)*2500

Example
18 Seer 5 Ton Heat Pump @.06KW
Cost =((60000/18)*(.06/1000)/.85)*2500
=((3333.33)*(.00006)/.85)*2500
=588.23

A 18 Seer 5 Ton Heat Pump would cost $588.23 annually to run.

Gas Furnace:

Cost of Operation=(Energy Cost/Energy Content) * ((BTU/1000) /Efficiency) * 100000

*Use 37.5 as energy content, as it is the closest available number.

Example
95% Efficient 80000 BTU Furnace
Cost =(.4168/37.5)*(80/95)*100000
=.0111146*.8421052*100000
=935.96

A 80,000 BTU with 95% Efficiency would cost $935.96 to run annually. This uses Energy Content as listed on nrcan.gc.ca for Toronto.

Water Heater:

Electric: Cost=365*(12.03/EF)*Cost/KWH

*this will give you the operational cost for a family of four. Divide in half for family of two. Multiply by 1.5 for family of six.

Example
Standard Electric water heater (85% Efficiency)
Cost =365*(12.03/ef)*cost/kwh
=365*(12.03/.85)*.075
=365*14.1529*.075
=387.44

A family of four with a standard electric water heater would spend approximately $387.44 a year on heating costs.

Natural Gas: Cost=365*(.4105/EF)*BTU fuel cost

*this will give you the operational cost for a family of four. Divide in half for family of two. Multiply by 1.5 for family of six.

Example
Family of 8 using a Hi-Eff NG water heater (65%EF)
Cost =(365*(.4105/.65)*.000015075)*2
=(365*.6315384*000015075)*2
=(347.45)*2
=694.90

A Family of eight would spend approximately $694.90 a year on water heating costs with a Hi-Efficiency Gas Water Heater