14 Things You Should Know About Air Conditioning

1. My home summer air conditioning bill is bigger per month than the winter heating bill per month. Traditional air conditioning is less efficient than heating and natural gas is less expensive than electricity.

2. Air conditioners have two motors that use electrical power. The compressor is the machine that makes the refrigerant cool the air. The other motor drives the fan that moves the air. Motors are energy hogs.

3. Every degree that you set your thermostat below 78 increases your air conditioning cost by 3 to 4%.

4. While your AC is working normally, you should feel the amount of airflow from your window unit or register for central units. You need to know what is normal to be able to trouble shoot problems.

5. Use a thermometer to check the room temperature and the temperature of the air that the AC is putting out. The air coming out of the AC should be about 20 degrees F cooler than the room temperature. Make a note what the difference is. This is good trouble shooting data for future use.

6. Air conditioning reduces the water vapor in the air turning it into liquid water. This makes us more comfortable by lowering the humidity in the home. The condensed water will flow down hill.

7. The water is supposed to drain outdoors from the back of a window unit, or to a basement floor drain for central air conditioning. There is a drip pan at the bottom of the window unit. There is a drip pan located under the cooling coil, inside the ductwork above your furnace for central air conditioning. The drip pan is there to catch the water and direct it the proper drain location. Seeing a lot of water going to the right place is very good news. It indicates that your AC is working as designed.

8. If water is draining to the wrong place, it can make an unpleasant mess. Window units should be tilted so the outdoor end is a little lower than the indoor end. If it is tilted, too much the wrong way water will drain into the house and make a mess.

9. Water from a central AC draining down inside of the furnace, will rust the furnace and destroy it before it wears out.

10. If the water is not draining, it will make ice and stop your AC from working. When the drip pan fills with water ice will start forming on the cold coil. The ice “grows upward” starting at the bottom of the cold coil. As the ice builds up it blocks the air flowing through the cold coil. You are likely to be unaware if the problem until the temperature in the house goes up. Given enough time a mixture of dust and dirt from the air, will plug the drain. Cleaning the drip pan and drain needs to be part of the pre-season maintenance.

11. How do you know when the coil inside the ductwork is iced up when you cannot see in there? If the fan is running but the airflow is reduced or stopped, it is iced up. See number 4 above.

12. If you do not take corrective action, the AC will continue to run wasting expensive electricity. The ice will continue to build up and the house will continue to get warmer. Action plan: Turn the AC off. Let the ice melt. Fix the drain problem. Turn the AC back on.

13. If the AC stops cooling but the air is flowing normally, the problem is not ice. If there is good airflow but the AC is putting out air that is not 20 degrees cooler than room temperature the problem may be due to low refrigerant level in the AC. See number 5 above. When the refrigerant leaks out the AC will continue to run wasting electricity. With low refrigerant, the AC will cool poorly and waste power.

14. What to do if your AC puts out a normal amount of air that is 20 degrees cooler than room temperature but the house does not cool down? The AC may be too small for the job. It needs your help. Action plan: Reduce the amount of outdoor hot air that is sneaking into the house. Shut off heat producing appliances and old style light bulbs. Close the storm windows and doors. Add more insulation to the attic. Spray water on the outdoor part of the central AC. Spray water on the house. Make shade for the house. Make shade for the AC. Buy another window unit. Pack up and move North.