Energy Saving Ideas

Boost Energy Efficiency with A New Air Conditioner

Keeping an air conditioner (AC) in good condition can dramatically increase savings by reducing the load on the air conditioner. If the AC unit is more than 15 years old, has compressor problems or if the cost of repairs approaches the cost of a new unit, replacing the air conditioner may be the best option.

Shopping for a replacement air conditioner can be a daunting task and the cost can be as much as $5,000. As with any major purchase, it is important to choose wisely. Some simple tips on selecting the correct size and energy efficiency rating for a home can make the job of buying a new AC easier.

Efficient Models Save Money
Overall energy efficiency is an important consideration when shopping for a new AC unit. Inefficient models may come with a cheaper initial investment, but high operating bills will easily end up costing more. Although energy efficient models typically cost more in the store, the amount of energy saved can actually pay back the initial cost of a new system within a few years depending on the usage, the cost of electricity and the summer temperatures.

Get SEERious About Efficiency
The first step in selecting an energy efficient unit is to look for the yellow EnergyGuideâ label on all new AC units. EnergyGuidesâ are useful for general comparison; however, the stated energy costs may not accurately represent your specific energy costs due to different lifestyles, comfort zones, air conditioner usage and utility rates.

Seasonal Energy Efficiency Rating, or SEER, measures the performance of an AC based on the amount of cool air divided by the electricity consumed over an entire cooling season. A minimum SEER of 10 for central air conditioners is required by the National Appliance Efficiency Standards, however, a wide selection of units are available with SEERs up to 17. Any AC unit with a SEER of 12 or higher is a very efficient system and will show an Energy Star® label.

The efficiency of a window air conditioner is measured by an Energy Efficiency Ratio, or EER. Although the national appliance standards require room or window air conditioners built after 1990 to have an EER of 8 or greater, in warm climates like Iowa a window air conditioner with an EER of over 10 is recommended. When comparing two units choose the one with the higher EER.

Don't Oversize
Oversized units cost more to buy and can decrease the unit's overall efficiency. Since air conditioners are designed to cool a fixed amount of space efficiently, oversizing an air conditioner will cause an increase in energy consumption. Along with consuming more energy, oversized units are less effective at removing humidity from the home. According to the Energy Star® website, a larger unit is not necessarily better and may not cool an area uniformly. A smaller unit running for an extended period will be more efficient and is more effective at dehumidifying than a large unit that turns on and off too often.

Over all, the best way to reduce the required amount of cooling capacity, the size and cost of the air conditioner unit is to reduce the number of air leaks in a home by caulking, weatherstripping and insulating.

More Information and Additional Resources
Some of this information was adapted from the American Council on an Energy Efficient Economy's publication, Consumer Guide to Home Energy Savings, 7th Edition, the Energy Efficiency and Renewable Energy Network as well as Homemade Money by Richard Heede and staff of the Rocky Mountain Institute.

Additional information on home energy savings can be found in the Home Series: Home Cooling booklet available on the Iowa Energy Center’s Web site, www.energy.iastate.edu or by calling (515) 294-8819.

The Iowa Energy Center is a nonprofit organization dedicated to increasing Iowa’s energy efficiency and the use of renewable fuels.

Contact: Amy Swenson, Iowa Energy Center, (515) 294-4391 swenson@energy.iastate.edu

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