Choosing the ideal 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 crucial role in keeping its system working safely, efficiently and for a long time.
A clogged furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also restricts airflow, which can damage your furnace and shorten its life span.
Making certain your furnace uses a clean filter that is ideal for your needs is not merely about keeping your furnace running efficiently. It’s also about delivering healthy indoor air quality for your home.
Your health is important to the HVAC professionals at Hoekstra - Paniccia Heating & Air Conditioning. We've long been dedicated to improving indoor air quality in Michigan City. Here, we’ve answered common questions about HVAC filters, including that especially 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
It's important to replace dirty air filters in a furnace or air conditioner routinely. Dirty filters cause the system to worker harder than it should because it takes extra work to pull air through the plugged-up filter.
Officials recommend examining your furnace filter monthly and replacing it if it’s dirty. You’ll know if the filter needs to be changed because it will coated with dirt or dust. Homeowners who have pets will probably have to replace their furnace air filter more often, because a good air filter will trap pet hair circulating in a home.
Locating Your Furnace's Air Filter
In general, a furnace air filter is usually found in the return air duct or blower compartment before the return air goes back into the furnace. This ensures air entering the system is filtered before it moves through the furnace components and is heated.
Depending on the type of furnace, the filter may be found on the right, left, bottom or in some cases, within the furnace. It's generally housed in a slot, frame or cabinet for convenient access and replacement. Always refer to your furnace's owner manual for important information regarding filter location of your furnace.
Is My Furnace Filter Just a Type of Air Filter?
The simple answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are essentially the same thing. While people may call them different things based on the current season— hot or cold—they are all filters that clean the air in your home.
They each remove dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making sure the air circulating throughout your home is clean and safe.
What Is the MERV Rating System and What Rating Is Best for Me?
Once you locate your old furnace filter and figure out when it should be substituted for a clean one, it’s time to pick a replacement. That means determining the level of filtration that you need. One way to do that is by picking 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 molecules. The rating scale ranges from 1 to 20, with higher numbers indicating the power to filter smaller particles.
Experts say a filter with a MERV rating between 8 and 13 offers an ideal balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with certain health conditions could need to use a filter with a higher MERV rating.
How to Place the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner correctly is crucial for the efficient operation of the heating or cooling system. Air filters are supposed to face a particular direction, indicated by an arrow written on the side of the filter frame. The filter should be put in with this arrow pointing toward the furnace or air conditioning unit, which is the direction of the airflow. If you're not sure about the airflow direction, try to remember that air always moves from the return duct towards the heat or cooling source. Therefore, make certain the arrow points in the direction of the furnace or air conditioning unit.
Many people are confused by which direction to face an air filter. To help remember, consider taking a picture with your mobile 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 inquire about this is during a regular furnace maintenance visit.
How to Replace Your Furnace Air Filter
Switching out the filter on your furnace or AC is an easy process. Here is a step-by-step rundown of how to retreive a dirty air filter and swap it for a new one:
- Turn off your furnace: Make sure to switch off your furnace before starting up the process.
- Find the furnace filter: Typically, the filter is found inside 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 replacement filter to point similarly.
- Slide out the old filter: Be mindful not to knock out any dust or particles.
- Document the date: Write down the date of replacement on the new filter's frame. This will make it easier to keep track of when it's time for you to change it again.
- Put in new filter: Put in the new filter with the arrow pointing at the furnace, which is the direction of airflow and should be the same direction the arrow pointed on your last filter.
- Secure the filter: Make sure the new filter fits securely and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the replacement filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The short answer is, yes, a dirty air filter can cause a furnace to cease working or decrease its lifespan. Changing your furnace or AC filter is one of the best things you can do to keep your system operating correctly.