If you look at your thermostat, you’ll see a fan option on the switch or touchscreen. We often hear, “Is it OK to run the fan without the AC?” The short answer is: Yes. You can run the fan with the AC off. Learn some practical reasons to do so and considerations if you plan to do it often.

Why Would I Run the Fan and Not the AC?

Even with the AC off, running the fan helps circulate air. You might not need cooling, yet your house feels stuffy. Running the blower can increase ventilation without turning on the AC and consuming more electricity. That’s if you don’t keep the blower running for too long. Usually, an hour will suffice, and you don’t have to risk contaminating your home with particulates and allergens by opening the windows.

A few reasons to run the fan alone include:

• More consistent temperatures
• Cleaner, fresher air
• Relief from allergies
• Less wear on the AC
• Increased AC lifespan

Can Running the Blower Fan Cause Problems?

There are caveats to letting the blower fan run all the time. These are important to consider as your HVAC system relies on the fan to blow air through the coils; this is the process that provides cooling. But if you keep the blower running, possible issues can include:

• Increased Energy Consumption: If the blower fan runs constantly, it will use more energy. While running it without the AC for a time uses less electricity, turning your air conditioner on and off will use more energy than if it runs constantly. Running the AC at low output requires less work to maintain indoor temperatures.

• Increased Wear: If you often shut down and start up your AC, it can increase wear and tear. Therefore, the risk of a breakdown increases. The unit may need more frequent repairs, so consider your comfort level before deciding to run the fan without the AC. If your home stays at a reasonable temperature with the AC off, then you can benefit by running the fan for a while.

• Warmer Air: On a hot day, running the AC blower fan alone can bring more warm air indoors. It can also increase humidity. Another consideration is whether your attic ducts are bringing in warmer air; running the fan without the AC can pull this air into your home.

• Clogged Air Filter: With air constantly running through the filter, it can clog up more quickly. You may need to change it more frequently to avoid airflow issues. Otherwise, a clogged filter will reduce airflow and force your system to work harder, consume more energy, and eventually break down.

• Indoor Air Quality: If dust, pollen, pet hair, mold spores, and other contaminants are present, the blower fan can re-circulate these in your home. Consider how your air quality is before deciding to let the fan run continuously.

Considerations If You Often Rely on the AC Fan

However, if you find you’re more comfortable, allergy symptoms go away or lessen, or there’s no change in your utility bills, it is OK to run the fan without the AC. But if you do it frequently, be sure to schedule professional AC inspections to find any problems that can occur. Also, consider features that let you program the blower fan to run automatically for specific amounts of time so you don’t have to remember to turn it on or off. 

Contact Sky Heating & Air Conditioning

A leading heating and cooling services company in the Portland area, we’re ready to address all your air conditioning needs. Our licensed technicians can fix any AC, furnace, or fan issue. With our Sky Signature Protection Plan, affordable inspections and tune-ups are available. For more details on our HVAC and other home services and to request help, schedule an appointment online or call (503) 694-4580 today.