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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 Effiency 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. If you are looking for a highly
efficient unit, consider the Amana RCE
Prestige Ultra.
SOUND RATINGS
- Depending on the location of your outdoor (condensing) unit and the floorplan 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 bels (similar to decibels), on a scale from 0 (barely perceptible) to 13 (the loudest). Most air conditioners operate at 8 to 9 bels. The quietest units operate at 6.8 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. If you are looking for a relatively quiet unit, consider the Amana Prestige Ultra RCE with its sound blanket and its quiet low (850) RPM Condenser Fan or a Lennox Elite 13 or Lennox Merit 12. These Lennox units use scroll compressors instead of traditional piston-driven compressors. The scroll compressors and these units' precision balanced direct drive fan allow them to operate without producing so much noise.
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.
**Note
that when it comes to air conditioning equipment, bigger is
not always better. An over size 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. |
