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. At this point, it should be pretty obvious that AUTO costs less than ON but let's math it out to its logical conclusion.
It could cost you hundreds of dollars a year. The average unit has a 500 watt fan, which uses almost as much energy over the course of the year as a refrigerator, resulting in a $50/month bill.
Running it continuously may lead to more frequent maintenance and repair needs. However, the added comfort and air quality benefits often outweigh these concerns. Noise: If you're sensitive to background noise, you might find the constant hum of the furnace fan bothersome.
A typical furnace fan uses 300 to 500 watts of electricity. Running the fan 24/7 can add $15 to $50 per month to your energy bill, depending on your local electricity rates.
Running the fan constantly uses a bit more energy, as you might expect, and this can increase your utility bill.
Using the “Auto” Setting
Increased energy efficiency by running the fan only when needed. Extended filter life as the fan operates less frequently. Lower energy bills due to reduced electricity usage.
Running your furnace fan continuously in winter has its pros and cons. It can improve air circulation and quality but may also lead to higher energy bills and increased wear on your system.
Keeping your fan on during the spring and summer can help reduce symptoms with constant circulation. That's because homes with circulating air tend to have better air quality and better dispersed allergens.
But first, here's the simple answer: 'roughly $0.19 a day — that's if you're running a 50-watt fan for 24 hours and the price of your electricity is $0.16/kWh, which was the average cost of residential electricity in Indiana in May 2023', according to energybot.com.
Air conditioners may use more electricity, especially in hotter months. Depending on local energy rates, running a few fans when needed can prove substantially cheaper in the long run.
If this is the case, then you'll need to find the fan limit switch and move it back into automatic mode. This will ensure that your furnace fan runs only when necessary and not continuously. The fan limit switch is typically located near the blower motor or in the control box.
Your blower motor circulates air through the furnace and can provide uniform temperatures. Many people leave their HVAC fan on all day, while others opt for two to three cycles per hour, ranging from ten to 25 minutes, depending on how close to heating or cooling temperatures they are.
Replacing a furnace blower motor costs $560, on average. Depending on the size and type of motor, most people pay $300 to $900. The average blower motor replacement cost is $560, but the final price depends on labor fees, as well as the cost of the parts.
When a furnace runs constantly, it probably means that something is dirty or clogged.
Running the HVAC fan by itself usually does not bring in outside air. The fan's job is to move air around your home. When you set your HVAC to “fan” mode, it circulates the air that's already inside your house. However, some systems have a fresh air intake that can bring in outside air when the fan is running.
"Most electrical fans are designed to be able to run continuously for several hours at a time, for example overnight or during the day, but you'll also need to keep in mind doing that continuously for long periods can cause wear and tear on the motor and other components, shortening its lifespan," continues David.
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. At this point, it should be pretty obvious that AUTO costs less than ON but let's math it out to its logical conclusion.
In conclusion, running your furnace fan 24/7 can offer several benefits, including improved air circulation, enhanced indoor air quality, humidity control, noise reduction, and even temperature distribution.
The switch that allows you to do this is commonly known as a summer switch. A summer switch is a small toggle switch attached to the furnace, which, when set to the 'on' position, will allow the furnace fan to run continuously. Another common place to find a summer switch setting is on your thermostat.
Leaving the fan running reduces wear and tear on the motor since it's not starting and stopping repeatedly. It's also beneficial to boost filtration, but leaving it on this setting has more drawbacks than benefits. When it runs nonstop, the fan consumes more energy, and the air filter needs frequent replacement.
The blower motor is particularly sensitive to dust and dirt; when it gets too dirty, it can't ventilate itself and may overheat.
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.
One of the most common complaints among homeowners who possess a furnace is that their unit runs continuously. Unless you also have a heat pump (which can cause your unit to run frequently to maintain a set temperature during extremely cold weather), your furnace should cycle on and off at regular intervals.
Although it is perfectly safe to run HVAC continuously, there are a few times you should shut it down. First, if your home is experiencing high summer temperatures and you have ductwork in the attic. It is difficult for even the best-insulated systems to fight off extreme temperatures.