Which Way Does The Furnace Filter Go?

Do you also have trouble running your HVAC at home, especially the part where putting the furnace filter in goes? If the furnace filter is not properly fitted then the heating applications in the house can work in an inefficient manner, the fuel costs will go up and heating devices may malfunction and thus lead to issues. However, there is no need to worry any longer because this is a perfect place for you to look for the solution.

Would you like to learn how to install and maintain a furnace filter properly? If so, then the following guide will help you install and take care of the device while also answering other questions like how to install and why you should install it.

Let’s get down to the real question without wasting time. You might be wondering, ‘How do I install the furnace filter properly?’ 

Feel free to follow along with the succinct yet detailed instructions given below:

1.  Turn off the Furnace: The last thing we’d want is an injury, therefore it is critical that the furnace is turned off using the thermostat or circuit breaker.
2. Locate the Filter Mounting Sock: The immediate goal now would be to identify the filter housing which is usually located near the furnace or in the return air duct.
3. Remove the screws, latches or clips: Always clean the filter with water and mild soap. You would also have to unscrew the filter housing in some furnace models to gain access to the filter.
4. Properly throw the old filter: The old filter should be thrown out and it should be taken out properly.
5. The arrow that is on the filter should be pointing towards the furnace when the filter is being installed: When installing a new filter, always ensure that it is installed correctly.
6. Closing the filter housing: While closing the filter housing you are required to take out the screws, latches or clips and then replace them.
7. Finally, flip the circuit on the breaker or thermostat: Whenever the heater is required, this can be done by switching on the thermostat and the breaker.

There’s always a reason behind why a certain thing works a certain way and you need to know ‘why’ and ‘how’ because this is as pivotal as getting the furnace filter installed the proper way.

First of all, why is it important to install a correct furnace filter?

1.  Airflow: If the furnace filter is installed backwards then it may restrict airflow which will be detrimental as it hampers the furnaces function of trapping air particles. And restricted airflow causes high pressure on the furnace making it work over time which can reduce its lifespan.
2. Quality of Air In Buildings: The improper fitting of furnace filters can hinder the eliminations of airborne allergens and other contaminants which affect the indoor quality of air.
3. Operational Efficiency of the Furnace: Operational efficiency of the furnace is greatly influenced by the furnace filter and if not installed properly then one might encounter increased bills, low efficiency, or even a faulty furnace.
4. Filter Longevity: If your filter gets clogged too often and its efficiency is compromised, then the reason must be improper installation. This has a negative impact on the time duration between replacements increasing the frequency of replacements.

The next question is how do we go about installing it properly. Let’s look at the steps needed: 

1.  Filter Orientation: On the side of the filter there is a directional arrow that needs to be pointed to the furnace tip. This needs to be taken into account when installing as it determines airflow direction.
2. Installation Manual: For further assistance, ensure you look at the manual that comes with the packaging for particular information on how to mount.
3. Airflow of the Furnace: Ensure the filter’s installation direction is equal to the airflow direction, which in this case is from the return air duct to the furnace.

In case of any issues faced by you during the installation of the furnace filter, please refer to the following troubleshooting guide: 

1. Airflow direction: Refer to consult your Furnace’s manual or contact a professional HVAC technician if you are unsure about the airflow direction.
2. Filter Housing Issues: To ensure proper filter installation and airflow, check for the damaged or rusted filter housing.
3. Filter size issues: Wrong filter size can also get you into a lot of trouble, exchange it with the manufacturer for the correct size.

Choosing the right furnace filter for your HVAC system can be daunting. Here’s how to go about looking to pick out the right furnace filter for your HVAC system:

1. Type: Settle for the type of filter that best addresses your heater’s needs considering your high efficiency filter requirements and HVAC system insulations. The available options include the disposable fiberglass filter and pleated filter.
2. Size: Just like the rest of the HVAC system components and accessories, the size of the furnace filter housing is important too.
3. MERV Rating: Minimum Efficiency Reporting Value rating is something that quantifies the filter’s ability to capture particles of different sizes so always opt for a filter with appropriate MERV rating for it.

If you’re done with the systems installation then there is the maintenance part that you need to handle as well.

Keeping a furnace filter clean should be a regular practice and here’s how it’s done: 

1. Replace: In accordance with the manufacturer’s recommendations, change the filter after 1-3 months alongside keeping your indoor air quality and your filter usage in mind.
2. Clean: Maintaining the filter housing should be a priority to curb debris and dust build-up inside it.
3. Monitor: Inspect the furnace and filter for possible restrictions or blockages to assess the airflow.

That is all that there is to it when it comes to properly reinstalling your furnace filter, and if you take the proper steps, it is quite a straightforward job. There are several helpful guidelines to remember at all times, make sure to read and follow the instructions provided by the manufacturers. By following these simple steps, you’ll help your HVAC system run smoothly and efficiently.

Correct Orientation for Different Filters

When installing furnace filters, it is important to ensure they work effectively. The correct orientation for a furnace filter depends on the type of filter you have.

1. Disposable Fiberglass or Pleated Filters

These are the most common types of furnace filters. They typically have a cardboard frame and are made of fiberglass or pleated fabric. The airflow direction usually matters for these filters. Look for arrows or markings on the filter frame; these arrows indicate the direction of airflow. You should install the filter with the arrow pointing in the direction of the airflow, which is usually toward the furnace or air handler. In most cases, this means the arrow should point toward the blower motor.

2. Washable or Reusable Filters

If you have a washable or reusable filter made of materials like aluminum or foam, they often don’t have specific airflow direction markings. In this case, you can install them either way, but it’s a good practice to install them in the same orientation as the old filter if you’re replacing one.

3. Electrostatic Filters

Electrostatic filters may have specific installation instructions provided by the manufacturer. Follow their guidelines, which could include an airflow direction indicator.

4. HEPA Filters

High-efficiency particulate air (HEPA) filters are very effective, but they can be restrictive to airflow. They often have a specified airflow direction to ensure they function correctly. Check for manufacturer instructions, and if there are no arrows, the air typically flows through the side with the metal or wire mesh.

Always refer to the manufacturer’s instructions if you’re unsure about the correct installation for your specific filter. Installing the filter in the wrong direction can reduce its effectiveness and strain your HVAC system, so it’s important to get it right. Regularly changing or cleaning your filter as recommended by the manufacturer is also essential for maintaining good indoor air quality and the efficiency of your heating and cooling system.

Furnace filter direction tips for different furnace types

Three types of furnaces are typically available in the Canadian market. Depending on the furnace type, the accurate location for the filter varies. But in most cases, the furnace filter is usually installed and positioned near the intake air blower fan to let air flows via the filter.

1. Upflow Furnace

An upright position is the most suitable location for most upflow furnaces. Placing them this way forces air from the bottom or side of the unit, then into the heat exchanger, and then it is forced upward into your building’s ductwork. Upflow furnaces are units placed in basements. In an up-flow furnace, the filter should be located in the blower chamber near the bottom of the unit, right next to the cold air return. With this furnace, the filter arrow should be placed facing upward.

2. Downflow furnace

With downflow furnaces, the air is taken in at the top, then heated inside, and then it’s taken out into your ductwork. Since it has downward-flowing air, make sure the filter is positioned at the top of the blower’s upper chamber. Downflow or attic furnace arrows should point down. In some downflow furnaces, a V-shaped filter system is installed, which requires two filters to be installed at the same angle in the chamber.

3. Horizontal furnace

In a horizontal furnace, air comes in from one direction, then extracts heat from it to cool it, and throws the air into a vent in the opposite direction. These furnaces usually come with a slide-in filter located on the side that draws cool air. The arrow point should be in the direction the wind is blowing.

How to install a furnace air filter in the right direction?

How to Install a Furnace Air Filter in the Right Direction

Now that you have determined the correct direction for your furnace filter let’s go through the step-by-step process of installing it properly:

• Locate the Filter: Find the filter’s location, which is typically where the ductwork meets the furnace. It will be closest to the unit and may be adjacent to the furnace.
• Remove the Old Filter: Remove the old filter from the filter air box on top of the furnace. Discard the old filter appropriately.
• Identify the Airflow Direction: Examine the new filter for an arrow indicating the proper airflow direction. The arrow should face toward the furnace and away from the return duct that draws the air in need of heating or cooling. To help you remember the airflow direction, you can use a permanent marker to draw an arrow on the furnace or ductwork.
• Install the New Filter: Slide the new filter into the filter air box with the arrow pointing towards the furnace. Ensure that the filter fits securely and is properly aligned.
• Regularly Monitor and Replace Filters: To maintain optimal performance, regularly monitor your furnace filter and replace it according to the recommended schedule. Keep track of the date when changing the filter to help you determine the duration between each alteration.

Safety tip: If the filter is placed inappropriately or in the wrong direction, the unit won’t adequately filter the air, causing damage to the HVAC unit. Also, it will reduce airflow via the furnace, making it use more power and work harder.
Bottom line

Hopefully, you understand that the arrow pointing to the filter is always positioned in the direction that air flows through the unit. If you know that the arrow should point toward the furnace’s heating chamber, you don’t need to rethink which way the filter goes or which side to install the filter on.

Final Thoughts

Proper installation of your furnace filter is crucial for maintaining the efficiency and longevity of your HVAC system. By following the guidelines outlined in this guide, you can ensure that your furnace filter is installed in the correct direction. Regularly monitoring and replacing your filters will help maintain optimal indoor air quality, energy efficiency, and the overall performance of your HVAC system. Remember, when it comes to furnace filters, “just go with the flow” to enjoy clean and comfortable air in your home.

Additional Information

It is important to choose the right-sized filter for your furnace to ensure a proper fit and optimal performance.

Some filters may have a filter rating or MERV (Minimum Efficiency Reporting Value) rating, indicating their efficiency in capturing particles of different sizes. Higher MERV ratings correspond to better filtration but may reduce airflow if not compatible with your furnace.

Consider consulting an HVAC professional for expert advice on furnace filter selection and installation. They can provide personalized recommendations based on your specific HVAC system and indoor air quality needs.

FAQ

Which way do you put the air filter in a furnace?

Furnace filters should be installed with the airflow direction in mind. Look for arrows on the filter; these arrows indicate the direction of airflow. The arrow should typically point towards the furnace or air handler, showing where the air is pulled in.

How do I know which way my air filter goes?

To determine the correct orientation, look for arrows or markings on the filter frame. The arrow will indicate the direction of airflow. If there are no arrows, consider the materials and construction of the filter (air often flows through the side with metal or wire mesh).

In which direction does air flow?

Air flows into the furnace or air handler through the return duct. So, the arrow on the filter should point in the direction of the return duct, which is typically towards the furnace.

How do I know if my furnace filter is backward?

If the filter is installed backward, the arrow or markings on the filter will point in the opposite direction of the airflow. You might also notice reduced airflow and decreased filter efficiency.

What happens if the furnace filter is backward?

If the filter is installed backward, it won't be effective at trapping dust, allergens, and particles in the air. Additionally, it can reduce airflow, making your heating and cooling system work harder and consume more energy.

What if my air filter has no arrow?

If your filter lacks arrows or clear markings, consider the filter's materials and construction. Air typically flows through the side with metal or wire mesh. If you're unsure, consult the manufacturer's instructions.

Where does the filter go on a downflow furnace?

In a downflow furnace, the filter is typically located in the return air duct, often near the furnace or air handler. The arrow on the filter should still point in the direction of the return air duct.

What happens if the air filter is installed wrong?

If the air filter is installed incorrectly, it can lead to reduced air quality, decreased filter efficiency, and increased energy consumption. It's important to install the filter correctly to maintain good indoor air quality and keep your HVAC system running efficiently. Remember that following the manufacturer's instructions, when available, is always a good practice to ensure your furnace filter is installed correctly and functions effectively.