Common Air Conditioning Terms

Air Conditioner repairman explaining cost of repairs to homeowners.

If you are in the market for a new AC system this summer, you might hear the terms SEER Rating and tonnage. But what do they mean and how do they affect which system you choose?

SEER Rating

SEER stands for “Seasonal Energy Efficiency Ratio” and is assigned based on standards developed by the Air Conditioning, Heating and Refrigeration Institute.

The ratings range from 13 to 25 and are assigned based on the amount of energy an air conditioner uses over the course of a year. The higher the rating, the more energy efficient the unit will be.

When comparing air conditioning systems for your home, keep in mind your seasonal usage. More efficient systems with higher SEER ratings will cost more up front, but provide long-term savings in lower utility bills.


Tonnage measures the amount of heat the system can remove from an area over an hour. This comes into play when considering the size of your new system. A system that is too small won’t cool properly.

A system that is too big will not remove humidity before cooling your home, thus creating an uncomfortable “cold swamp” atmosphere. In addition to the size of your home, factors such as floor plan, air flow, insulation, number of windows, and ceiling height can effect required tonnage.

Contact Us for a Quote

If you are considering a new AC system this summer, Haldeman Mechanical can help you determine the most appropriate model to meet you specific needs. Contact us today!