subject: Energy Ratings for a Portable Air Conditioner [print this page] Energy Ratings for a Portable Air Conditioner
There are two primary numbers to consider when evaluating the energy efficiency of air conditioners are the BTU rating and Wattage. The Energy Efficiency Ratio, or EER, is a calculated number found by dividing the BTU rating by the Wattage used. Air conditioner manufacturers are required to include the EER with each unit, but the number isn't always advertised! It is best to use the spec sheet numbers to calculate EER, because the BTU rating there will be a true number, not rounded up for advertising. The BTU rating tells how much heat the unit can remove from the air in one hour under standard conditions, basically indicating how well it cools air. The Wattage is how much electricity it requires to remove that heat. These numbers are always included in the specifications of a portable air conditioner. The higher the EER, the more efficient the air conditioner. (One will also hear of the Seasonal EER, or SEER, which is used for central air conditioners but not portable units).
The portable air conditioner industry does not yet have standards like other types of air conditioner. The last time the government established such standards was before most people had even heard of a portable air conditioner. There are also no established Energy Star Rating criteria in portable ac's, but manufacturers often comply with the 10-17 EER required for other types. Since the compressor (a heat producer itself) is located inside instead of outside, and because the unit must pump exhaust air through a 5 inch duct (which has resistance and increases the work load), a portable air conditioner will generally operate less efficiently than a comparably powered window or split air conditioner , .
The EER is not the primary concern when selecting an air conditioner. Buyers should first make sure they get adequate cooling capacity for the intended use. As stated in other articles, it's a good idea to get a portable air conditioner that is a rated for a room larger than the one for which it is intended. Once a buyer figures out which units best fits their needs, EER should be used as a comparison tool to find which unit will adequately cool most efficiently.
