The number one reason you don't want the fan to run continuously is that your air conditioner is probably oversized. Since your AC is responsible for doing two jobs, cooling and dehumidifying, moisture from the air condenses on the cold evaporator coil when it runs.
Your AC might shut off when its coils have frosted over. Evaporator coils are located inside the unit's air handler. Clogged air filters and other airflow issues can cause frost to build up over time, which can lead to short cycling.
Faulty thermostat. If your thermostat is not working correctly, the unit doesn't know to turn off even when the temperature is reached. If enough cool air escapes, the temperature in your space never reaches the set point and the system will keep running. Dirty or blocked condenser.
When it is set on “auto”, the fan turns on ONLY when your system is running. When the thermostat reaches your temperature setting, the system, including the blower fan, shuts off. When the thermostat switch is set to “on”, the fan is CONSTANTLY blowing, even when your system isn't working to heat or cool the air.
The most common reason that your Air Conditioner fan won't turn off is because a stuck relay keeping the circuit closed. Set the desired temperature above the current room temperature so the air conditioner unit turns off (set the thermostat below room temperature in the winter to check your furnace).
Pros to Keeping Fan Continuously Running:
Less frequent starts and stops of the fan can reduce the stress from startup, and potentially help extend its lifespan. Leaving the fan on 24/7 ensures cleaner air, as the air is pulled through the filtration or UV light system (assuming you have one of these features).The fan mode shows that the air conditioning system is in ventilation mode. It is one of the most energy-efficient modes to use in both cooling and warming modes. While in this state, the air conditioning is only using the fans to maintain the ambient temperature of the room.
Malfunctioning Thermostat – A faulty thermostat can cause your AC fan to run constantly by not knowing when the desired temperature has been reached. If the actual room temperature is below what your thermostat is set for, there's a good chance you're due for a repair or replacement.
A typical AC fan motor uses about 500 watts when it's running. Therefore, the fan uses about 360 kWh per month in the ON mode. The average kWh in the US costs about $0.12 so it costs about $43 per month, or about $520 per year, to run a fan continuously.
The most common reason that your Air Conditioner fan won't turn off is because a stuck relay keeping the circuit closed. Set the desired temperature above the current room temperature so the air conditioner unit turns off (set the thermostat below room temperature in the winter to check your furnace).
The main reason is AC cools the room faster than a ceiling fan. AC in fan mode consumes less power and gives less air flow. If you sit near the AC you will feel cool yourself, but remains of the room would be still warm.
Cool Mode:
This is the default mode on which the air conditioner runs to cool the room. You can adjust the fan speed and temperature. To save electricity while using this mode – it's best to set the temperature at 25 degree centigrade.Keeping your fan on AUTO is the most energy-efficient option. The fan only runs when the system is on and not continuously. There is better dehumidification in your home during the summer months. When your fan is set to AUTO, moisture from cold cooling coils can drip and be drained outside.
Don't Leave your HVAC Fan On. If you are turning on your AC, you may have been advised to put the fan in the 'on' position in order to distribute the cooler air around the house. Moisture from the air will condense on the evaporator coil when the AC is running because the evaporator is so much cooler.
Cause #2: Dirty evaporator and/or condenser coil
If your inside unit's evaporator coil is dirty it makes it tough for refrigerant (or “Freon”) to absorb heat from your air. Basically, both issues will cause your system to run constantly since it's struggling to remove heat from your home.11 easy ways to lower your air conditioning bill this summer
- Upgrade your windows. If your home has old windows, they might not be energy efficient.
- Seal your windows.
- Install a programmable thermostat.
- Use ceiling fans.
- Replace your HVAC air filters.
- Avoid cooking indoors.
- Reduce the sunlight.
- Insulate your walls and attics.
If there's something wrong with your AC that makes it shut off after just 15 minutes, it's usually one of these issues: Unit is overheating. This often means there is simply a buildup of grime inside the compressor unit, but it could also mean there's a refrigerant leak or have other causes. Faulty thermostat.
Setting Your HVAC Fan to “ON”
When you set your fan to “ON,” you're telling it to keep running 24 hours a day, 7 days a week, regardless of the heating or cooling setting. Less frequent starts and stops of the fan can reduce the stress from startup, and potentially help extend it's lifespan.Fans are cheaper to run than air conditioners, and can be used in place of air conditioners or along with them to save money. You can actually raise the thermostat on your air conditioning unit by 4 degrees without lessening the cooling effect if you turn on the ceiling fan.
Setting Your HVAC Fan to “ON”
When you set your fan to “ON,” you're telling it to keep running 24 hours a day, 7 days a week, regardless of the heating or cooling setting.
