Air Conditioning

Types of Air Conditioners

Air conditioners can be organized several ways, but the easiest is by type. All units can be divided into three distinct major types: single stage, two stage, and variable speed units.

Efficiency or SEER Rating

“SEER” is an abbreviation for “seasonal energy efficiency ratio.” The SEER (or efficiency) rating of an air conditioner refers to how much electricity the unit will use to keep you cool during a typical season. Higher numbers are better: the higher the SEER, the higher the efficiency is, and the less electricity the unit will consume.

Tonnage or Capacity

The “tonnage” of an air conditioner refers to the unit’s ability to remove heat from your home. The heat contained in buildings is measured in tons.

To give you an idea of what a ton of heat is, imagine a block of ice weighing one ton. One ton of heat is the amount of heat it would take to melt that block of ice in an hour. A ton of heat is also equivalent to 12,000 BTUs or 18,000 burning matches.

Residential air conditioners are made in sizes of 1.5 to 5 tons. They usually increase size in half-ton increments. The job of an air conditioning contractor is to determine what size (or tonnage) unit you need for your house. In this case, is it not a matter of “the more, the better.”

An oversized air conditioner will not remove the proper amount of moisture from the air. An undersized air conditioner will run constantly even at moderate temperatures and will not adequately condition the space. Since every home is unique, the best option is often to choose a two speed or variable unit. They work well even when slightly oversize.

Adding a variable speed furnace will help you remain dry as well as cool.

Single Speed Air Conditioners

Single speed air conditioners produce the same amount of heat removal all the time regardless of how hot and muggy it is outside. They are built to handle the hottest days of the year. While this is great in July, it means that they are larger than needed the rest of the time.

A good contractor will select a unit slightly smaller than what is needed for peak temperatures, since most of the time we do not see peak temperatures. Matching your unit to the temperatures you see most of the time will be more efficient and save you money.

Two Speed Air Conditioners

Two speed air conditioners have two distinct output capacities to better condition your home. These units can change the amount of cooling capacity they produce depending on how hot it is. Because they can slow down and run longer, they do a better job of removing moisture and providing enhanced comfort.

Variable Speed Air Conditioners

We recommend Variable Speed units for large homes. Instead of turning on and off all day to adjust the temperature, they run at a variable speed. They have 700 different outputs, which means they can accurately provide temperatures to within 1/10th of the degree you want. They provide exceptional comfort and moisture removal, with none of the hot and cold temperature swings typical to one and two speed units.