The SEER rating of an AC unit is the measure of the efficiency which the unit operates. Short for Seasonal Energy Efficiency Ratio, a SEER rating reveals the amount of cooling in BTU divided by the amount of electricity it uses in watts.
The higher the SEER rating the more efficient the unit is. Units with a higher SEER rating use less energy to cool a house and therefore cost less to operate according to Energy Star.
Since a home air conditioner has a lifespan of approximately 12-20 years it makes the most sense to get as high of a SEER rating as you can afford. In 10 or 15 years that previously high SEER rating will be considered low by the current technological standards and will cost significantly more to operate.
In most states the minimum AC SEER rating you can find is 13 and the highest is around 25. Energy standards continue to creep forward and the industry is looking to mandate a minimum rating of 15 SEER for new units soon.
For every increase of SEER point you gain about 7% in efficiency over the previous unit. For example a 14 SEER unit will save you around 7% on the cooling portion of your energy bill compared to a 13 SEER unit. A 15 SEER unit will save you around 14% over that same 13 SEER unit.
If you live in a hot climate where you run your air conditioner a considerable portion of the year, then upgrading to a higher SEER is an easy decision.
For folks in colder climates the decision is not as easy, but any upgrade will yield considerable savings over the course of the next decade or two that the unit is installed.
When purchasing a new AC unit consider that this unit will generate the lion’s share of your summer utility bills. Keep in mind that while you gain around 7% with each increase in rating, that 7% is of a smaller total number so there is a lessening of total savings with each increased rating.
In my experience as a general contractor I would stay in the range of a 16-20 SEER unit. The value from the very top and very bottom of the market are not worth it in the end and you’ll find success in the middle of the pack in this case.
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