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Buying an Air Conditioner

Repair versus Replace

When your cooling system breaks down, you may be faced with the choice of repairing your existing unit or purchasing a new air conditioner. ACU Air focuses on educating its customers so that they themselves can make an informed decision regarding the replacement or the repair of existing equipment. Repairs may be the least expensive immediate option, but may cost the consumer more in the long run. An older system that breaks down once is likely to break down again and it will consume more energy than a newer system. In fact, installing a new, energy efficient system can pay for itself over time. However, many times simple repairs can prolong the life of an air conditioner and replacing the equipment may not be the most sensible option.

Selecting a Unit

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

R22 versus R410A Based Equipment

Beginning in 2010, The United States prohibited the production and import of R22 (Freon) charged air conditioning equipment. For a while this meant that all consumers purchasing a new condenser had to purchase R410A (Puron) based equipment. If their existing evaporator coil was not compatible with the new refrigerant, it had to be replaced as well. Since then, importers and manufacturers have found a legal way around this restriction. They "dry ship" R22-compatible condensers, meaning they ship the units without any refrigerant in them. Once the contractor has installed the unit, he charges it with R22. The ability to purchase an R22 compatible air conditioner mainly benefits homeowners whose existing evaporator coils cannot be converted to use R410A refrigerant, as both the condenser and evaporator coil must use the same type of refrigerant in order to operate. For the past several years, evaporator coils have been designed in such a way that they can be converted from one type of refrigerant to another by changing out the thermal expansion valve. If your evaporator coil can be converted to R410A refrigerant and you have to replace your condenser, we recommend upgrading your equipment to R410A. Likewise, if you are replacing both your evaporator coil and your condenser at the same time, it's advisable to upgrade to R410A. The reason for this recommendation is that, over time, R22 is expected to become increasingly more expensive and it may, at some point, become more difficult to obtain.

Efficiency Ratings

In general, the more efficient the unit, the more it will cost initially. However, more efficient equipment will actually save you money over time as it requires less power to cool your home. Cooling efficiency for air conditioners is indicated by a SEER Rating (Seasonal Energy Effiency Rating): the higher the number, the greater the efficiency. If you plan to be in your home for several more years, you can save money, in the long run, by purchasing equipment which has a SEER rating that is 1 or 2 SEER above the current minimum standard. However, do not get carried away and purchase equipment that has the highest available SEER rating. If you do so, the extra money you spend up front to purchase the equipment may far exceed the total savings you will experience in electricity costs over the lifetime of the unit.

Sound Rating Numbers (SRN)

Depending on its location, a noisy condensing 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 bels, on a scale from 0 (barely perceptible) to 13 (the loudest). Most air conditioners operate at 8 to 9 bels. 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 with additional features that provide greater comfort. Two-speed units run on low-speed (using about 50% of the energy) 80% of the time. They use fewer on/off cycles and produce fewer drafts and much smaller temperature swings.


In order to achieve comfortable cooling and dehumidification, the air conditioning system must be correctly sized. Traditionally, central air conditioning units have been sized in tons, with one ton cooling 12,000 BTUs per hour. As a general rule of thumb, you need 12,000 BTUs or 1 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. In the past, you could divide the square footage of your living space by 500 to determine the number of tons you need. However, manufacturers have re-engineered their equipment and some of the new equipment now cools fewer than 12,000 BTUs per advertised ton. Consequently, if you need to replace your existing equipment, you may have to buy a larger unit (more tons) than your present unit, in order to get the same amount of cooling. To insure that you purchase the right equipment, you will need an experienced air conditioning technician to visit your residence or business and identify the size and model of equipment which will best meet your needs.

Note that when it comes to air conditioning equipment, bigger is not always better. An over size unit will lower the temperature of the living space too quickly and will shut off before it has adequately dehumidified the air. Excessive humidity facilitates the growth of mold and mildew.

Selecting a Contractor

Improperly installed equipment may not work correctly, may create environmental or safety hazards, and may waste your time as you wait for repair calls. Make sure that the company you use is fully licensed and insured and that it warranties its work. Below is a checklist for selecting the right contractor.