Is It Recommended to Run a Furnace Fan Continuously in Winter?

A furnace is the most common heating system in Canada, especially in colder regions like Ontario and Alberta. Over 50% of Canadian homes use furnaces because they are efficient even in freezing weather. Compared to other systems, such as electric baseboards, heat pumps, and boilers, furnaces win as they quickly distribute heat in extreme temperatures.

However, there’s an ongoing debate: should you run your furnace fan all the time? Some homeowners believe that a continuously working fan keeps indoor temperatures balanced and improves air circulation. But others question the cost of running a furnace fan continuously. Let’s review both scenarios and find the golden mean.

How does a furnace fan function?

The main task of a furnace fan is to circulate heated air throughout the house. Located inside the furnace unit, it pushes warm air generated by the furnace through ductwork and evenly distributes it to different rooms. When the furnace heats the air, the fan kicks in to deliver that warmth efficiently and maintain a consistent indoor temperature. The fan is responsible for heating and not only that. It can also work independently of the furnace to circulate air, which can help improve air quality and maintain even temperatures across the house.

What are the working modes of a furnace fan?

Furnace fans typically operate on two main settings: auto and continuous. In the auto setting, the fan turns on only when the furnace is actively heating. When the thermostat reaches the desired temperature, the fan stops until heating is needed again. This setting conserves energy, as the fan only runs periodically. In the continuous setting, the fan operates non-stop, regardless of whether the furnace starts heating. This continuous mode can lead to a slight increase in energy usage, but it has its advantages, as you can avoid temperature fluctuations, balance humidity, and keep air cleaner with regular filtration. So, is it better to have a furnace fan on auto or on? The best setting often depends on a homeowner’s comfort needs and energy efficiency goals.

Benefits of running the furnace fan continuously

Running furnace fan continuously in winter can be beneficial in a few ways:

• Even temperature throughout the home
  When the fan is on, you will enjoy a balanced temperature in all rooms. You will not have hot or cold spots – the fan circulates warm air more evenly and keeps all areas comfortable. This is an important advantage for large or multi-story homes.
• Cleaner, healthier air
  When the fan is always running, it pulls air through the furnace filter more often. So, the filter captures dust, allergens, and other particles. This additional filtration can improve air quality, which is especially helpful for those with allergies or asthma.
• Potential for energy savings
  Modern HVAC systems often have energy-efficient fans that can run continuously on low power. This can reduce system load and may lead to lower energy bills. Is it ok to leave furnace fan on all the time? If your furnace has this type of fan, then you can keep it switched in to keep your home comfortable and not worry about killing utility bills.

Drawbacks of continuous furnace fan operation

Running your furnace fan non-stop does have a few downsides you should know about:

• Higher energy costs
  Does running a furnace fan use much electricity? If you have an older furnace, a continuously working fan can increase your energy consumption. Older fan motors are not energy-efficient and use more power in this mode. Without an efficient motor, it is better to avoid this working setting.
• Extra load on the system
  A fan that runs around the clock will wear out faster than one that only turns on as needed. Continuous operation can overload the motor and cause malfunctions. You will face unwanted repairs or part replacements. You may even need an earlier system replacement.

If you want to run your fan continuously, check whether your furnace can handle it without driving up costs. If you have an older system, it may be necessary to upgrade to a model with higher energy efficiency.

When is it fine to run the furnace fan continuously?

Sometimes, running your furnace fan all the time can be helpful, but you should think about your specific needs and climate. Here are some situations when it is a good idea:

• Poor airflow in your home. If your home has a layout that makes it hard for air to flow naturally, a fan running all the time can spread warm air evenly, helping to eliminate cold spots.
• Bad indoor air quality. If someone in your home has allergies or breathing problems, running furnace fan continuously in summer and winter will help filter out allergens and make the air cleaner.
• High humidity levels. If you have damp areas in your home, like basements or bathrooms, a running fan can reduce humidity levels.

Tips for effective furnace fan operation

Follow these simple rules to make the most of your furnace:

• Do not ignore maintenance. Have your HVAC system checked regularly. Change the air filter in the furnace every 1-3 months to keep the airflow clear. A clean filter helps improve air quality and lets the furnace work better.
• Use a programmable thermostat. If possible, get a programmable thermostat. This lets you set times for when you want the fan to run so it works when you need it and saves energy when you don’t.
• Seal and insulate ducts. Make sure your ductwork is sealed and insulated properly. This prevents air leaks and lets warm air reach all rooms effectively.
• Consider a whole-house fan. You may consider installing a whole-house fan for increased ventilation and improved air quality. It is especially helpful in warmer months.

Wrapping up

Should you run your furnace fan continuously in cold and warm seasons? There is no correct answer to this question. It all depends on your specific preferences and situation. Running the fan all the time helps distribute heat more evenly, improve air quality, and lower humidity levels in your home. However, it can also lead to higher energy costs and additional wear on your heating system, especially if you have an old one.

Consider the benefits and drawbacks to see what’s best for your home. For example, if you have a multi-level home or are dealing with allergies, keeping the fan on might be a good idea. Regular maintenance of your HVAC system and a programmable thermostat can keep your furnace more efficient. Do not hesitate to test two modes, measure energy consumption and choose the variant that suits you best.