Room Air Conditioner Cost Estimator
Compares the energy and economics of high efficiency and standard efficiency air conditioners.
From the Pacific Northwest National Laboratory
These cost estimators are screening tools that estimates a product's lifetime energy cost savings at various efficiency levels. The tools provide energy and cost estimates, suitable for comparison purposes only. They are not designed to replace building load simulating software for cooling systems design. Actual performance and costs will vary depending on specific operating conditions. American Air Conditioning LLC Hawaii is not responsible for any adverse outcome associated with results generated by the cost estimators.
Let's say that you have a choice between two 10,000-BTU units. One has an EER of 8.3 and consumes 1,200 watts, and the other has an EER of 10 and consumes 1,000 watts. Let's also say that the price difference is $100. To understand what the payback period is on the more expensive unit, you need to know:
Let's say that you plan to use the air conditioner in the summer (four months a year) and it will be operating about six hours a day. Let's also imagine that the cost in your area is $0.10/kWh. The difference in energy consumption between the two units is 200 watts, which means that every five hours the less expensive unit will consume 1 additional kWh (and therefore $0.10 more) than the more expensive unit.
- Approximately how many hours per year you will be operating the unit
- How much a kilowatt-hour (kWh) costs in your area
Assuming that there are 30 days in a month, you find that during the summer you are operating the air conditioner:
4 mo. x 30 days/mo. x 6 hr/day = 720 hours
[(720 hrs x 200 watts) / (1000 watts/kW)] x $0.10/kWh = $14.40
Since the more expensive unit costs $100 more, that means that it will take about seven years for the more expensive unit to break even.
See this page for a great explanation of seasonal energy efficiency rating (SEER).