How Do I Increase the Airflow in My Furnace?

Millions of furnaces are currently in use in America, yet many issues creep up regularly, causing them to operate inefficiently.

One of the most annoying problems that come with a furnace is low airflow. There are several ways that you can increase the airflow in your furnace. 

Try the below methods to increase the airflow in your furnace: 

  • Clean the furnace air filter. 
  • Replace the furnace filter.
  • Clean or replace the air return filters. 
  • Remove obstructions from vents. 
  • Clean the return grill. 
  • Seal leaking air ducts. 

The above methods may seem difficult, but we assure you that they are doable.

In this article, we will give you step by step instructions for how to increase the airflow in your furnace. If you’re interested in learning more, then keep on reading!

5 Ways to Increase the Airflow in Your Furnace

It’s extremely frustrating when your furnace isn’t blowing out enough air.

To remedy the problem, you may think that you need to call in a professional. While this may ultimately be necessary, you should try to fix the problem first using the following 5 methods. 

Clean Your Furnace Air Filter

While the majority of furnaces were designed to use disposable filters, some of them use washable filters.

If you have a furnace that uses washable filters, and you haven’t cleaned it in a while, now is the time to clean it. A clean filter will allow for greater airflow from your furnace.  

If you’ve never cleaned your furnace filter, you should do so immediately. A furnace filter cannot allow enough air to pass through if it’s already clogged up with debris, pet hair, and other particles.

You should clean your furnace filter once every three months. However, your actual filter cleaning frequency depends on how often you use the furnace.

If you use the furnace more in the wintertime, as most people do, then you need to clean your filter more often than every 90 days.

Furnace before and after cleaning

How to Clean Washable Furnace Filters

Cleaning a furnace filter is relatively easy. In the following list, we will take you through all the cleaning steps:

  • Remove the dirty filter from the furnace and place it on the floor. Be careful not to swing it because this could dislodge dirt and debris.
  • Vacuum the filter with a hose attachment. Try to suck up as much debris as possible.
  • Rinse the filter. Since filters are large, you will need to use a bathtub or oversized sink to rinse the filter. Use warm water for best results. As you rinse the filter, you should use a brush or your hand to loosen up the debris and wash it away. 
  • Let the filter air dry. 

After your clean filter is placed back in the furnace, you may notice that the airflow is greatly increased.

Replace Your Furnace Filter

If you have a furnace that uses disposable filters, cleaning the filter is not an option. To help increase the airflow in your furnace, you will need to replace your disposable furnace filter every so often.

Some begin to have problems after not changing their filter for a month, while others are able to go up to 90 days between filter changes.

Disposable filters can get grimy and clogged, just like washable ones can. Over time, dust particles and grime accumulate in the filter and block air from getting through.

The process for replacing a furnace filter is relatively easy. The following list will tell you exactly how to go about it:

  • Locate the filter door on your furnace. On many furnaces, the filter door will be labeled.
  • Open the filter door. Depending on your furnace make and model, you may need to use a screwdriver to loosen screws.
  • Remove the filter. Pull it up, out, or to the side to remove it.
  • Replace it with the new filter. When replacing the filter, ensure that the filter is facing the right direction. For instance, if the air flows up, the arrow should be facing upwards.
  • Replace the filter door.

Clean or Replace the Air Return Filters

You may think the furnace is to blame for low airflow. But it could be that your air return filters are clogged and need to be replaced or cleaned. 

Many people forget about their air return filters in the grand scheme of things, which is understandable. However, this is a very common culprit behind decreased airflow from the furnace.

HVAC Return Air Wall Register Vent

Furnace filters require regular maintenance, and so do air return filters. You should clean or replace your air return filters to remove hair, dirt, and other debris. A good rule of thumb to follow is to clean your filters every month or so.

You can easily clean your sir return filters with a vacuum, a soft bristle brush, and a thorough rinse.

Remove Obstructions from Vents

Without even noticing it, most of us cover up our vents with curtains, furniture, and other objects.

This has the unfortunate effect of blocking airflow from the furnace. Of all of the ways to increase airflow, removing items from in front of your vent is the easiest.

Rearrange the furniture in your rooms to minimize obstruction. If you have curtains over the air vents, secure them with an elastic band to keep them out of the way.

Clean the Air Return Grill

No matter how clean your air return filters are, if the air return grill is grimy and dusty, the air will not be able to get through it efficiently.

To maximize the airflow from your furnace, take your air return grills off and clean them thoroughly. You may be surprised by the amount of debris you’ll find when you take the grill off.

After your grills are totally clean, you may notice a notable difference in the amount of warm air that is circulated through your home.

Seal Leaking Air Ducts

The ducts that come from your furnace can develop leaks over time. If your system is old and none of the previous recommendations work, consider whether there is a duct leak.

To test for a duct leak, turn on your furnace and run your hand across any accessible air duct connections. If you feel any air escaping, this is a clear indication that there’s a duct leak.

Take your time as you feel around for a leak. This will increase the chances that you’ll locate any existing leaks.

HVAC Return Air Duct Repairing

How to Fix a Duct Leak

Fixing a duct leak is not a very complicated task.

You can use duct sealing tape to seal the leak. However, you may find that duct sealing tape does not hold up for long.

Also, if your ducts happen to get oily, the duct tape may not adhere properly. If you have your mind set on using tape to stop a duct leak, just make sure that you use actual duct sealing tape.

Duct sealant is another option that you can try to fix leaky ducts.

You can get a paintbrush and some sealant at your neighborhood home improvement store and brush the sealant onto the affected area. You can also use sealant with duct sealing tape to make the fix last a bit longer.

Note: Duct leaks can happen in areas of your home that you can’t reach. For this reason, we recommend that you consult an HVAC technician to do a professional inspection and repair of your ducts. Going the professional route for duct leaks can end up saving you headaches and money on energy costs.

Tips to Keep Your Furnace’s Airflow Strong

Now that you know how to troubleshoot and fix a furnace airflow problem, you could benefit from knowing how to keep your airflow in your furnace strong.

The following list will give you all the tips you need!

  • Figure out how often you should change your filter. There will often be a recommendation on the packaging of your filters to tell you how often to change them. However, your specific household type and habits may require you to change your filters at a different frequency. For instance, if you have pets and you live in a cold climate, you may need to change your filter more often.
  • Choose the right filter for your household. Not all filters are created equally. Filters are classified based on a range, from MERV 1- MERV 20. MERV 20 filters out the most particles and is the most efficient. On the other hand, a Merv 1 filter will not do much filtering at all but will decrease visible dust. 
  • Don’t be afraid to call an HVAC Technician. In an effort to save money, most of us shy away from calling professionals. However, DIY repairs are often inefficient and could cost you more money than you would have if you’d called a professional in the first place. 

Final Thoughts

Now you know of several ways to increase the airflow from your furnace, and you’ve gathered some useful tips. We hope that this article serves as a guide to help you with your furnace issues.