home energy efficiency Running costs. Once you have decided on the air conditioning system for your home you will probably be interested to know how much it will cost to run.Actual running costs depend on the size of the unit and how much time it is operating at full load and your local electricity cost.The examples below will give you an idea of the maximum cost per hour for heating and cooling.In the product information you have received there will be several numbers that will help you understand how much it will be to run the system for both heating and cooling..g.2 Running cost = 1.84 X 25 = 46 cents per hour. For the same unit the Cooling Capacity is 6.0 divided by EER of 3.26 = 1.84. 1.84 X 25* cents = 46 cents per hour. For heating use the heating capacity and the COP figures instead of cooling capacity and EER.