Myth: Turning the thermostat way down will cool the home faster.
On standard air conditioning systems turning the thermostat far below the current temperature will not affect the rate of cooling at all. They are single speed cooling so when they are on they are on at full blast 100% of time. On multiple stage air conditioning systems setting the thermostat more than a few degrees below the current temperature will ensure that your air conditioning turns on to its highest stage. Chances are very good though, that if your air conditioner is running for more than 10 minutes that it is already in its primarily and largest cooling stage. For optimum efficiency and cooling you should set and forget the thermostat when you are home. Fiddling with the thermostat just won’t do the trick.
Myth: To save energy you should have the thermostat off when you are not home such as at work during the day.
Yes, this will save you energy, but you defeat the purpose of the air conditioning system when you do this. The first purpose of the air conditioning system is to remove moisture from the air. Once the moisture from the air is being decreased the comfort level and temperature of the air will be increased. It is far more efficient and comfortable to have a secondary set point on your thermostat for your “away” periods. So if you are comfortable at 75 degrees you should turn your thermostat to 80 degrees (about) when you are at work and not at home. This will enable your air conditioner to not cycle on and off as often and still remove moisture from the air when you are away at work. This allows your home to reach a comfortable temperature and moisture level once you arrive at home more quickly. Having a setback thermostat is very helpful here as you can set the air conditioner to come on 30 minutes or more before you arrive home to get you home to an optimum temperature. If your home gains as little as 24,000 BTUs an hour (2 Tons) and you are gone for 8 hours this means you could have a total heat gain of 192,000 BTUs (16 Tons). This would take a 4 Ton air conditioner approximately 4 hours of continuous operation to remove. Allowing your home to heat up during the day to well past your comfortable point will only mean that you will be uncomfortable for hours as the air conditioner removes the excessive heat buildup.
Myth: Purchasing an energy efficient air conditioner will save on electricity bills.
This is a long standing myth perpetuated by the manufacturers and then in turn by the utilities and the EPA. The secret is out and has been for several years. Installing high efficiency equipment by itself does not automatically reduce your electric bills and may actually increase them. Installing new equipment can significantly reduce your heating and air conditioning bills provided that the systems are installed correctly, correctly matched, correctly sized and sealed. Most air conditioning duct systems leak profusely. Sealing these ducts will enable your bills to see dramatic reductions that new equipment just cannot match. Most heating and air conditioning contractors oversize new air conditioning systems to avoid having the “not enough” cooling complaints. A properly sized and installed air conditioning system, not just the box outside, will increase comfort and savings.
Myth: The air conditioning system should cool the home in about 20 minutes.
This is a common misconception. A properly sized air conditioning system should be able to keep up with the heating load during the average summer day. The internal temperature in the home should increase during hotter than normal days and the air conditioning system should run continuously. On cooler than normal days the air conditioner should cycle on and off more quickly. While running your air conditioner for 20 minutes will make you feel cooler, especially if you are sitting below a supply register, but the furniture, the walls and the every solid object in the home will not be cool. Once the oversized air conditioner shuts off, the air temperature quickly exceeds the set point on the thermostat and the air conditioner turns back on. This constant on-off cycling is detrimental to the life of the air conditioner and will increase utility bills.
Myth: Home air conditioners last only 10 to 12 years.
While it is common for air conditioning systems in homes to fail somewhere in or near to the 10 – 12 year mark, it should not happen. Nearly all failures related to heating and air conditioning system are the result of a lack of maintenance and improper installation. Lack of maintenance is paramount in extending the life and usability of your air conditioner as well as keeping your utility bills as low as possible. When the filter is dirty, the blower wheel is dirty and the evaporator coil is dirty the airflow through an air conditioning system is reduced. This opens up the chance for the Freon to return to the outdoor unit in a liquid form. If this happens the compressor will fail. The compressors simply cannot compress a liquid. The Freon pressures indicating low on Freon and lack of airflow are virtually the same. The temperatures are different, but many service technicians charge Freon by pressure rather than by pressure and temperature. This situation leads to overcharging the air conditioner with Freon which makes it work harder and eventually causes it to prematurely fail. When checking the Freon charge in any residential air conditioner it is critical to measure the airflow and verify that at least 350 cubic feet of air is being moved per Ton of air conditioning.