Auto vs Fan position on thermostat?
auto vs fan
auto vs fan on your thermostat is a commonly debated question. This decision plays an important role in your monthly electricity bill totals. Who knew this switch was so important?
This is a commonly asked question. And this discussion specifically is based on warm, humid climates like Florida. This decision plays an important role in your monthly electricity bill totals and energy consumption. Who knew this switch was so important?
The On/Auto fan switch on your AC thermostat has one function. The fan circulates the air throughout your home. Like any fan in your home, running it continuously costs money. By turning the fan in the On position, it will run continuously to circulate the air in your home. The On position will also require more frequent maintenance and air filter change out.
Turning the fan to the Auto position, will only circulate the air until the desired temperature is reached (the temperature you have set on your thermostat). A major factor affecting the Auto setting in your air conditioning, especially in Florida, is dehumidification. Setting the fan to Auto helps the dehumidification process. Your AC system sweats and having breaks in between when the AC fan is running allows your system to get rid of that moisture through the condensation pan and lines. If your fan constantly runs, that moisture cycles back into your air making it more humid.
The fan in the On position does not usually work to well in humid climates because once a normal conditioning cycle is complete, there is still water and moisture on the evaporator coil and in the drain pan. If the fan continues to blow, it will inadvertently blow that moisture into the duct system and the home creating higher humidity levels and in some cases, mildew growth on supply registers and air ducts.
As far as costs are concerned with the auto vs fan debate, the fan in the On position costs more money because it is running continuously. And running your air conditioning fan all of the time also runs down your equipment faster.
However, there is nothing to say that you can’t use both settings, On and Auto, depending on your needs and habits. One suggestion to get the best of both worlds is to use On while you are home and Auto while you are away. However, in Florida, Sunset Air professionals recommend you not use the AC Fan in the On position because of our high humidity.
There is another option, though! If you’re interested in breathing clean air and in the comfort that the On setting can provide but you are concerned about higher electricity consumption, you may want to consider installing a two-stage or variable speed system. These equipment options are great for optimizing dehumidification in your home or office. The variable speed air handler is just one part of the equation. You must also have variable speed compressors. These compressors act as the brains of the system and do what your environment is requesting. This means you are conditioning the air all the time. This type of system runs nearly all the time so it circulates the air more often. However, since it has multiple speeds and the amount it runs depends on air flow, it tends to use less energy than your average air handler.
So, having your AC fan in the Auto position saves you money in the short-term with your electricity bills and in the long-term by helping equipment to last longer. There are also options to use both of the settings depending on your desires and an options for different equipment. Now you know the on vs auto debate and how you can put it to work for you!