ACU	Air

Heating and Air Conditioning

Repair versus Replace

Selecting a Unit

R22 versus R410A Based Equipment

If you have not replaced your air conditioning system recently, your condenser and evaporator coil probably use R22 to cool your home or place of business. The problem with R22 is that when it escapes into the atmosphere and breaks down, it emits chlorine atoms which damage the ozone. Consequently, the United States has prohibited the production and import of R22 based air conditioning equipment effective January 1, 2010. If you replace your equipment after that date, you will have to purchase R410 based equipment. Commonly referred to by the brand name Puron, R410A does not damage the ozone. If you need to replace your air conditioning equipment before the ban takes effect, you have the choice of purchasing R22 based or R410A based equipment. Note that both your condenser and your evaporator coil must use the same refrigerant, so if your R22 condenser or evaporator coil fails and you choose to replace it with R410A equipment, you will have to replace your other unit at the same time. Bear in mind that if you replace only the failed unit with new R22 equipment and the other unit fails after January 1, 2010, you will have to replace both units with R410A equipment. Consequently, it may be cheaper, in the long run, to replace both your condenser and your evaporator coil, at the same time, with R410A based equipment, if one unit fails before 2010 than it will be to replace the failed unit twice (once with R22 based-equipment and later with R410A-based equipment) should the second unit fail after January 1, 2010.

Generally speaking, R410A units are slightly more efficient than R22 units. Furthermore, R410A based compressors run cooler than R22 based compressors and, consequently, are less likely to overheat and burn out. Another benefit of R410A air conditioning systems is that they use new, synthetic lubricants that are more soluble than the mineral oil traditionally used to lubricate R22 systems. The synthetic lubricants circulate more efficiently thereby reducing wear and tear on the unit's moving parts. Furthermore, because R410A operates under much higher pressure than R22, R410A based condensers are constructed with stronger, thicker shells, which reduces the noise and vibrations created by the compressor and, subsequently, puts less of a strain on the piping connections, reducing the incidence of refrigerant leaks.

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 fuel to cool your home. Cooling efficiency for air conditioners is indicated by a SEER (Seasonal Energy Effiency Rating): the higher the number, the greater the efficiency. In 1992, 10 SEER was the minimum rating for units installed in new homes. The Department of Energy has since set a new minimum standard of 13 SEER for air conditioners manufactured on or after January 23, 2006. 13 SEER equipment is approximately thirty-percent more efficient to operate than 10 SEER equipment. For even greater energy savings, consider 14 SEER, 15 SEER, or higher equipment. The most efficient air conditioning equipment we offer at this time is Carrier's state-of-the-art Infinity Series with an exceptional efficiency rating of up to 21.0 SEER. The Infinity's two-stage compressor operates at low speed eighty percent of the time, using minimal electricity while providing optimal comfort.

Sound Rating Numbers (SRN)

Depending on its location, a noisy condensing unit may destroy the peace and quiet of your garden or may 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. As a general rule, R410A based condensers are quieter than R22 based units. Because R410A operates under far higher pressure than R22, the R410A units are constructed with a stronger, thicker shell, which reduces the noise and vibrations created by the compressor. One of the quietest units currently on the market is Carrier's Performance Series condenser, registering 6.7 to 6.9 bels, thanks to its patented Silencer System II. The Performance Series exceeds industry standards by employing a specialized motor mount, a compressor sound blanket, forward swept fan blades, a laminated sound elimination compressor mounting plate, and a silencer airflow baffle.

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 small temperature swings.

Size

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 most new 13 SEER 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, run a heat load, 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

		The contractor possesses a valid air conditioning license issued by the State of Texas. Manufacturers may not warranty equipment that is purchased and/or installed by someone other than a licensed contractor (or an employee working under a licensed contractor). The contractor's license number should be displayed on all company vehicles, advertisements, business cards, and invoices.
		The contractor carries liability insurance.
		All employees who handle refrigerant are EPA certified. Refrigerant (often referred to by the brand name Freon) is a controlled substance. Any time a unit containing refrigerant is to be moved or disposed of, an EPA certified technician must first use a recovery unit to remove the refrigerant.
		The contractor runs a criminal background check on all field service technicians and installers.
		The contractor pulls all required permits. If you live inside an incorporated area, such as Shenandoah, Oak Ridge, or Conroe, a permit may be required for new installations.
		The contractor includes a one year labor warranty on newly installed equipment. Some contractors limit warranty work to weekdays only; others will perform emergency warranty work in the evenings and on weekends, if the equipment fails after hours. Ask before you buy!
		The contractor provides a written estimate before performing the work. The written estimate should include disposal of the old equipment, installation of the new equipment, the refrigerant required to charge the system, any required permits, and sales tax.

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