AC efficiency

Okay, so summer is fast approaching! It is time to brush up on the terminology of summer, air conditioning and recent efficiency measurements.

The Federal government has introduced standards for air conditioning and heating because these units require some form of fuel and/or refrigerant. In the past the most common type of refrigerant (that which makes air conditioners pump out cool air) was very harmful to the ozone layer. To combat this and encourage the use of more environmentally friendly refrigerants, the rating system of SEER came about.

SEER stands for Seasonal Energy Efficiency Ratio - which is "based on four tests developed by the US Department of Energy. It is measured in Btu's of total annual cooling divided by the energy usage in watt hours."

SEER is usually the number that you will hear referred to most often. The higher the SEER, the more you will save on your energy bills. The lower the SEER, the more energy the unit will use with less cooling output. A lesser known, but equally important number for efficiency ratings is EER.

EER stands for Energy Efficiency Ratio. This number is "based on a single test at 95 degree farenheight outdoor temperature. It is the ratio of cooling capacity in Btu's per hour divided by the electrical energy input in watts."

Besides making life more complicated...WHY are there two measurements for efficiency?

Well, SEER complies with Department of Energy requirments and at a certain level, units recieve certification which homeowners can then use to determine their savings. The EER rating is often utilized by energy/electricity companies because the higher the EER, the higher the savings of actual energy watts.

Today, if you are looking at rebate materials from your local energy company, or if you are looking to get a healthy tax break for next year, the requriements are always listed in SEER and EER. Understanding these terms can save you money - especially if you are currently looking for a new unit. The higher the number - the better!

Source: MSI HVAC "Air Conditioner Efficiency Measurements" February, 27, 2009.