Picking out the correct furnace filter and changing it when it becomes dirty is as important to your HVAC system as changing the oil is to your car. Each plays a vital part in keeping its system running safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, enabling potentially harmful particles to flow through your home. It also slows airflow, which can damage your furnace and decrease its life span.
Making sure your furnace uses a clean filter that is ideal for your needs is not just about keeping your furnace working efficiently. It’s also about creating excellent indoor air quality for your household.
Your health is important to the heating and cooling pros at Haselhoff Air Solutions. We've long focused on enhancing indoor air quality in Ames. Here, we’ve answered frequent questions about HVAC filters, including that very tricky question of what direction do you point a filter in your furnace or air conditioner?
How Often to Replace the Air Filter in a Furnace
Experts stress it's vital to replace dirty air filters in a furnace or air conditioner regularly. Dirt-clogged filters cause the system to worker harder than it should because it takes extra effort to force air through the plugged-up filter.
Officials recommend checking your furnace filter every 30 days and replacing it if it’s dirty. You’ll know if your filter needs changing because it will coated with dirt or dust. Those who have pets that shed will very likely want to replace their furnace air filter more often, because a quality air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is normally located in the return air duct or blower compartment before the return air gets to the furnace. This is so air being pulled into the system is filtered before it passes through the furnace components and is heated.
Depending on the furnace model, the filter may be found on the right, left, bottom or in some cases, inside the furnace. It's typically housed inside of a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for facts concerning filter location of the furnace in your home.
Are Air Filters and Furnace Filters the Same Thing?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are effectively identical. While people may call them different things based on the current season— warm or chilly months—they are all filters that clean the air in your home.
They each get rid of dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, making certain the air circulating throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Should I Have?
Once you find your old furnace filter and figure out when it should be changed, it’s time to choose a replacement. That means determining the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV is short for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating the power to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having good indoor air quality without unnecessarily restricting airflow. However, people with certain health conditions may need to purchase a filters with a higher MERV rating.
Where to Insert the Air Filter in a Furnace or Air Conditioner
Installing an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the system. Air filters are supposed to face a specific direction, indicated by an arrow printed on the side of the filter frame. The filter should be installed with this arrow pointing toward the furnace or air conditioner, which is the direction of the airflow. If you're unsure about the airflow direction, it may be helpful to remember that air always moves from the return duct towards the heat or cooling source. Therefore, make sure the arrow points at the furnace or air conditioner.
Many people struggle with which direction to install an air filter. To help remember, consider taking a quick picture with your cellular phone after the filter has been accurately installed by a professional. Or, you also could ask a technician to use a marker to write on the outside of your furnace which direction the filter should point. A perfect time to ask about this is during a regular furnace maintenance visit.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or AC is a simple process. Here is a step-by-step list of how to retreive a dirty air filter and exchange it for a new one:
- Turn off your furnace: Be sure to turn off your furnace before starting up the process.
- Look for the furnace filter: Typically, the filter is found within the furnace or in the air return vent. Take note of which direction the arrow points on the filter, because you’ll want the arrow on the clean filter to point similarly.
- Remove the old filter: Be diligent not to knock out any dust or debris.
- Document the date: Write down the date of replacement on the new filter's frame. This will help your family keep track of when it's time for you to change it again.
- Insert new filter: Put in the new filter with the arrow pointing in the direction of the furnace, which is the direction of airflow and should be the same direction the arrow pointed on the dirty filter you just removed.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that secure it in the compartment.
- Turn on your furnace: Once the new filter is properly in place, you can turn your furnace back on.
Can a Dirty Air Filter Damage My Furnace?
The simple answer is, yes, a dirty air filter can cause a furnace to stop working or shorten its lifespan. Changing your furnace or AC filter is one of the best things you can do to keep your system running effectively.