It’s a purchase you make perhaps once in ten years. You’re concerned about efficiency and comfort. But how do you know which brand and model to choose. Understanding the standard ratings applied to air conditioners can help.

Efficiency Ratings

In general, the more efficient the unit, the more it will cost initially. However, the more efficient, more expensive unit will actually save you money over time as it requires less fuel to cool your home. If you are concerned about efficiency, watch for the Energy Star Label. Cooling efficiency for air conditioners is indicated by a SEER (Seasonal Energy Efficency Rating). The SEER rating tells you how efficiently a unit uses electricity: the higher the number, the greater the efficiency. The typical SEER rating of units manufactured prior to 1992 is about 6.0. In 1992, the government established a minimum cooling efficiency standard for units installed in new homes at 10.0 SEER. High efficiency units have a rating of at least 12.0 SEER.

Sound Ratings

Depending on the location of your outdoor (condensing) unit and the floor plan of your home, a noisy unit may destroy the peace and quiet of your garden and may even be a sound nuisance when you’re indoors. The sound level of outdoor units is measured in bells (similar to decibels), on a scale from 0 (barely perceptible) to 13 (the loudest). Most air conditioners operate at 8 to 9 bells. The quietest units operate at 6.8 bells. This may not sound like a wide range, until you learn that a 9-bel unit is 10 times louder than an 8-bel unit. In other words, one 9-bel unit makes as much noise as 10 8-bel units put together.

Comfort Features

Some air conditioners come additional features that provide greater comfort. Two-speed units can run on low-speed (using about 50% of the energy) 80% of the time. Consequently, they use fewer on/off cycles and produce fewer drafts and much small temperature swings.

Select the Correct Size

In order to achieve comfortable cooling and dehumidification, the system must be correctly sized. The size of central air conditioning is measured in tons. (1 ton = 12,000 BTU/HR).

As a general rule of thumb, you need one ton of cooling for each 500 square feet of living space. This ratio assumes that the space you are cooling has standard 8 foot ceilings, that windows make up less than twenty percent of southern facing walls, that your windows have drapes or blinds and that you close them during the heat of the day, and that your walls and attic are insulated.

The chart below offers a general guideline for sizing residential systems in Travis and Williamson Counties.

Keep in mind that this is only a guideline and that skylights, type of insulation, the number and size of south facing windows, protective shade trees, etc. can significantly affect the size of system required. Ideally, the technician should perform a load calculation to determine what size unit would best suit the space to be cooled and heated.

Note that when it comes to air conditioning equipment, bigger is not always better. An oversize unit will lower the temperature too quickly and will shut off before it has an opportunity to properly dehumidify the air being conditioned. Excessive humidity can create an environment which facilitates the growth of mold.

Air Conditioning & Heating Repair Service: Shelton’s Pride A/C and Heating has highly-trained technician’s always available nights, weekends and holidays to repair any heating & cooling problem.

Air Conditioning & Heating Preventive Maintenance Programs: To prevent repair problems and extend HVAC equipment life, Shelton’s Pride A/C and Heating highly recommends seasonal inspections and tune-ups on all heating and air conditioning equipment. Whether you are interested in a one-time tune-up on a furnace or air conditioning unit, or a full-year Preventative Maintenance Program offering tune-ups, discounts on products and service, and priority service – It’s Shelton’s Pride A/C and Heating. Contact us to inquire about our comprehensive air-conditioning and furnace tune-ups.

Air Conditioning & Heating Replacement Add-On Equipment: Shelton’s Pride A/C and Heating offers a huge selection of HVAC equipment (furnaces, air conditioners, heat pumps and air handlers) to meet any home comfort need.