How to Use Air Conditioning Efficiently

We love air conditioning. Good ol' A/C. Keeps us cool and comfortable. Until we get the electric bill. Then we get "hot" about the cost. Fact is most people do not use their air conditioning effectively or efficiently. Now you're not going to save bundles of money by being more conscious of the way you use A/C, but it can make the pain a little more tolerable.

Whether you have a central A/C system or room units, you can save by following a few simple rules.

Maintenance: Just like any mechanical system, your air conditioner needs regular maintenance to operate at peak performance. Clean or replace your filters once a month! This is true for a room unit or central system. There seems to be an idea that high efficiency filters last longer. Leave them in for 3, 6, 12 months. Not true, they are finer and therefore filter smaller particles. This means they generally get dirty quicker. Often these filters can be detrimental to your systems efficiency by restricting air flow. You should check with your HVAC technician before using high efficiency filters such as HEPA types. In extreme cases they can cause the indoor cooling coils to freeze, which may result in damage.

The indoor cooling coils in the air handler should be cleaned once a year. Dirty coils are less efficient. The fan blades in the air handler should also be cleaned. Clean blades move more air.
Clean condensate lines and check and clean the pump if your system is equipped with one. Be sure system shutdown switches are working. Look over the catch pan under the air handler if unit has one. Be sure there are no holes or cracks.

The outdoor compressor is the heart of a central A/C system. Keep the area around the unit clear and free of debris. Restricting the air flow from the unit will impede its' ability to dissipate heat causing it to work harder. Have the cooling fins cleaned once a year. The same is true for room units. Don't blow lawn clippings into the unit! Or if your clothes dryer is venting lint into the fins, find a way to correct this.

Clean your ducts! This is a greatly overlooked area of forced air maintenance. Dirty ducts are first and foremost unhealthy. You should consider cleaning your ducts every 3-5 years.

Using your system efficiently: The best way to use a central air conditioning system is to not open your windows when the temperature cools down for one or two days. The job of the A/C system is to; one: cool the air and two: dehumidify the air. By opening windows you re-humidify the air in the home and when you restart the system, it will have work to once again dehumidify the air.

A very important consideration is where you set your thermostat. 78 degrees is the optimal temperature for central A/C systems. 78 is not uncomfortable especially if the air is dry. Contemplate this fact, for every degree you deviate from 78 it will cost you about three percent more per degree to run you A/C. Using ceiling fans will also allow you to more comfortably raise the temperature and use the unit less.

Automatic or setback thermostats can save you money by raising the temperature setting while you are away from home and lowering it before you come back. Raising the temperature for a period of about eight hours is recommended in order to realize any savings. Shorter periods may not save you any money or may even cost you. Be aware and experiment with setting these devices around your schedule.

All ducts should be insulated and sealed. Duct leaks can be responsible for up to a 30% loss in efficiency. The same is true for insulating ducts, especially in unconditioned spaces such as an attic.

Some other points to remember are close your shades and blinds during the day. Insulated shades are a good way to keep the heat out of your home. Avoid using your oven, cook on the stove top or better yet the microwave or barbecue outdoors. If you have a ventilating hood run it to spot remove the heat to the exterior, but don't over do it, this will draw some hot outdoor air into the home.

Size matters: Bigger is not better with air conditioning. If your system is too large, either central or room units, it will not effectively dehumidify the air. This will make the home very uncomfortable. It will be cool, but feel damp or "clammy".

Whirlpool has a cooling capacity calculator that you can use to choose the correct size room air conditioner for your application. With central air the system is sized by an HVAC technician using heat load calculations.

When choosing any air conditioner the higher the efficiency the lower the operating cost. Central units are rated in SEER (Seasonal Energy Efficiency Ratio). The minimum federally mandated rating since January 23, 2006 is 13. SEER 13 is 30% more efficient than the previous minimum SEER of 10.

Room air conditioners are rated by the energy efficiency ratio (EER). The higher the EER rating, the more efficient the air conditioner. National appliance standards require room air conditioners built after January 1, 1990, to have an energy efficiency ratio (EER) of 8.0 or greater.

When buying a room air conditioner, look for units with an EER of 10.0 or above. Check the Energy Guide label for the unit, and also look for room units with the ENERGY STAR label.
A little consideration should be give to where you install your air conditioner. If possible, install the unit in a shaded spot on your home's north or east side. Direct sunshine on the unit's outdoor heat exchanger decreases efficiency by as much as 10%.

By following these tips you will save money and be more comfortable. And you may find the painful cost of comfort might just be a little more bearable

James Quarello
JRV Home Inspection Services, LLC