Picking out the right furnace filter and changing it when it is 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 working safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, allowing 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 appropriate for your needs is not only about keeping your furnace operating efficiently. It’s also about delivering healthy indoor air quality for your home.
The health of your family is important to the heating pros at Alpine Summit Heating & Cooling. We've long worked with an eye on bettering indoor air quality in Athol. Here, we’ve answered frequent questions about HVAC filters, including that particularly tricky question of what direction do you point a filter in your furnace or air conditioner?
When to Replace the Air Filter in Your Furnace
It is vital to replace dirty air filters in a furnace or air conditioner regularly. Dirty filters cause the system to worker harder than it should because it takes more energy 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 filled with dirt or dust. People who have dogs and cats will probably have to replace their furnace air filter more often, because an effective air filter will trap pet hair circulating in a home.
Where Is the Air Filter in My Furnace?
In general, a furnace air filter is commonly installed in the return air duct or blower compartment before the return air reaches the furnace. This ensures air flowing into the system is filtered before it goes 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 usually housed inside of a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for information regarding filter location of your particular brand and model of furnace.
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 basically the same. While they might be called different things based on the current season— hot or cold—they are all filters that clean the air in your residence.
They each eliminate dust, allergens, bacteria and other airborne debris 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 the MERV Rating System and What Rating Is Best for Me?
Once you track down your old furnace filter and decide when it should be substituted for a clean one, it’s time to select a replacement. That means picking the level of filtration that you need. One approach to this is by choosing an appropriate MERV rating for your needs.
MERV is an abbreviation for Minimum Efficiency Reporting Values. The MERV rating calculates the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with greater numbers indicating a greater ability 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 overly restricting airflow. However, people with some health conditions could need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Positioning an air filter in a furnace or air conditioner properly is necessary for the efficient operation of the unit. Air filters are supposed to face a particular direction, indicated by an arrow printed on the side of the filter frame. The filter should be placed in the unit 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, remember that air always moves from the return duct towards the heat or cooling source. Therefore, be sure that the arrow points in the direction of the furnace or air conditioning unit.
Many people struggle with which direction to point an air filter. To help remember, consider snapping a quick photo with your cell phone after the filter has been correctly 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 go. A great time to inquire about this is during a routine furnace maintenance appointment.
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 exchange it for a new one:
- Turn off your furnace: Make sure to switch 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 replacement filter to point in the same direction.
- Slide out the old filter: Be mindful not to knock out any dust or dirt.
- 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.
- Slide 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 the old filter you are replacing.
- Secure the filter: Make sure the new filter fits nicely and close any latches or clips that lock it in place.
- Turn on your furnace: Once the new filter is completely in place, 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 shorten its lifespan. Changing your furnace or air conditioning filter is one of the easiest things you can do to keep your system operating correctly.
