Your furnace filter will last longer.
Forced air heating fan on or auto.
The primary advantage of the auto setting is that it uses less energy.
To be safe unless you have a specific reason to keep the fan running constantly just place your central air or furnace fan setting on auto.
Would that just suck out all the cool air.
The auto setting turns the fan on only when the air conditioning or furnace is actively running.
Also i have a huge air register in the middle of the living room floor.
If you set your furnace fan to auto the fan will only run when the system tells it to in order to keep your home as warm as you want it based on your thermostat settings.
On means that the fan is constantly on and blowing air when your hvac system is not heating or cooling air.
What are the pros and cons of the fan on or auto settings.
This means that at times it will circulate cold air.
The fan s auto setting works with your heating cooling system so your fan is running the least amount of time needed at the slowest speed.
Auto means that the fan turns on automatically only when your system is heating or cooling air.
Auto helps distribute air in the beginning of the cooling or heating cycle and then cuts off when the set temperature is reached.
Once the thermostat reaches the desired temperature the entire system shuts off until the next cycle.
When your system reaches the temperature you ve set for it the fan will shut off until the next cycle.
The auto setting means less energy usage because it keeps the fan running the least amount of time at the slowest speed needed for heating and cooling.
The auto setting can cut some of that cost.
If your fan is running constantly the heat exchanger never gets a chance to cool down either which can cause serious issues.
The fan will start about 40 seconds after the burners light and go off about one minute after the temperature is satisfied.
If your fan runs constantly your monthly heating bills will be higher.
My forced air gas furnace is in the crawl space.
Because the fan only runs when your home is in a heating or cooling cycle there are times when the fan is completely off and doesn t.
This means it s consuming less energy than when it runs non stop which means lower furnace bills.
Running your fan on auto or on is a personal preference.
On cooling the fan will run only when the air conditioner is running.
There are two settings on your thermostat to control the fan auto or on.
If you have your furnace again or air conditioning fan set to auto your system s fan will run during the furnace s heating cycle only.
Leaving the fan set to auto if you set your thermostat to on you will most likely pay more month to month on your energy bills.
Don t run the fan in the heat of the summer.