Myth 1: Buying an efficient air conditioner will automatically reduce my energy bill.
Fact: This true to some extent, but you will not realize all the possible savings if the equipment is not sized or installed properly. Studies have shown that typical air conditioner installed with wrong ductwork design will consume up to 1/3 more energy than a properly designed system. New equipment needs to be designed and installed properly. The very first thing that must be done is a load calculation of your home based on the construction materials in your home, orientation to the sun, and number of occupants. Rule of thumb sizing and load calculations are the worst ways to calculate the size of equipment for your home. Have your contractor measure and draw your house in a software program designed to do load calculations. Then you can expect to see the savings with your new high efficiency equipment.
Myth 2: The higher my Seasonal Energy Efficiency Ratio (SEER) the more I will save on my electric bill.
Fact: If it is not designed correctly it will not make a difference. In fact a badly installed 21 SEER machine will deliver energy savings equal to a 10 SEER machine. As the outside conditions change the air conditioner designed to work at full load (95 degrees outside and 75 degrees inside) will start to lose capacity as the temperature outside reaches its design temperature. Poorly designed ductwork leaking will cause capacity to drop off dramatically. Here is a quick check measure the outlet leaving your air conditioner and measure it at the farthest supply grille. Then measure the return and subtract it from the supply. Here is an example return temperature 87 degrees supply 63 degrees = 24 degrees across the equipment. Supply grille 68 degrees (68-63 =7) 7 divided by 24 = .29 or 29% duct leakage.
