Installing and Maintaining Air Conditioners For Best Energy Efficiency
There are steps you should take to make sure your air conditioner, whether it's central air or a room model, runs at peak efficiency.
Central Air: the compressor of your central air conditioner should be located in a cool, shaded place outside. Your best bet is the north side of your house under the shade of trees or tall shrubs. But make sure it has an unimpeded air flow, so keep the Kudzu away from it. If the compressor has to go on the roof or on the east or west side of the building (usually a bad idea), make sure it is completely shielded from summer sun by plantings, an awning or a fence.
Have your central air contioning unit inspected, cleaned and tuned by a professional every two to three years to keep it going longer and using less electricity. If your refrigerant needs to be recharged, make sure it is done correctly. If it is overcharged, it will reduce operating efficiency and could damage the unit. Iif it is undercharged it will also use energy less efficiently.
While the technician is working on your central air conditioner, make sure s/he measures the airflow over the indoor coil. Average air flow rates tend to go down over time if there is poor maintenance. This could reduce your unit's efficiency by 5-10 percent.
Make sure your duct system is well sealed. This could save you 10-15 percent of the electricity you pour into your air conditioner.
Finally, turn off the power to the central air conditioning unit when the warm months are over. Otherwise, the heating elements in the unit (strange, but there are heating elements in an air conditioner) will eat electricity during the winter. If your unit has a separate switch, flip it. If there is no switch, flip the circuit breaker to turn it off. Remember to turn the power back on for at least 24 hours before you start the unit back up next year to prevent damage to the compressor.
Room Air Conditioners: I realize you are more limited when installing a room air conditioner since it has to go where the wall or window is. The best thing you can do is choose a north wall if possible. If not, go with a south wall. Avoid east or west walls because the direct sunlight will reduce the unit's efficiency.
For room air conditioners, be sure to clean their air filters every month. Dirt that impedes the air flow not only makes them use more energy, it could cause damage to the unit. Also, make sure the condenser is professionally cleaned every year if it's dusty where you live. Otherwise, have it cleaned every two years.
Steps to Take to Make Your Air Conditioner Work Less Hard
No matter what type of model you have, close doors and windows while running your air conditioning. Don't use a whole-house fan or window fan while your air conditioner is on.
On the other hand, do use your ceiling fan. It will allow you to set your thermostat at a higher temperature and still stay comfortable. You will be comfortable at about 78 degrees Fahrenheit without the ceiling fan. With each degree you raise the thermostat, you will save 3-5 percent on the portion of your electric bill going to air conditioning.
If you have central air conditioning, shut off registers to unoccupied rooms. Be sure not to shut off too many registers, though, or you may harm the compressor with the increased pressure.
Don't use your "outside air" option very often, if you have one. You will spend a lot more for the electricity to cool down the incoming outdoor air than you would just to recirculate the already cooled indoor air.
Keep down the humidity. Use the bathroom exhaust fan while showering. Make sure your dryer is venting outside. Dry things (clothes, firewood, etc.) outside.