How energy efficiency in air conditioners is calculated:
Energy efficiency of an air conditioner is calculated as the amount of Btu (British thermal units) per hour drawn for every watt of power that the air conditioner uses. In the case of room air conditioners, this is calculated as an energy efficiency ratio (EER). Efficiency in central air conditioners is measured as a seasonal energy efficiency ratio (SEER). These ratings are available on all new air conditioners and can be seen in the energy guide that is provided with them. The energy guide provides valuable information such as the annual operating cost of the air conditioner. Manufacturers that adhere to energy star standards will voluntarily label their products. Appliances with higher EER and SEER ratings will often cost more. However, the amount of savings incurred when using these conditioners makes the investment worthwhile.
Average performance of an air conditioner:
The average EER rating of a room air conditioner is between 5,500 Btu per hour and 14,000 Btu per hour. New air conditioners usually have a minimum EER rating of 8. People living in a mild climate area should buy air conditioners with a rating of 8 EER. People living in more hot climates have more strenuous cooling needs and will require an EER rating of at least 10. Replacing older air conditioners with modern energy-efficient models can substantially reduce the amount spent on cooling the house.
Current energy efficiency requirements:
Under new national standards, central air conditioners require a SEER rating of 9.7 for a single packaged AC and 10 for a split system. Today, central air conditioners come with SEER ratings as high as 17. The SEER is calculated by dividing Btu by watt per hour. This is cooling output divided by power consumption. The higher the rating, the more efficient is the unit. Energy efficiency can be substantially improved by upgrading to an air conditioner with a higher SEER rating. For example, by switching from a SEER 9 to a SEER 13 appliance, one can reduce energy consumption by 30%.
