Choosing the proper furnace filter and changing it when it gets dirty is as important to your HVAC system as changing the oil is to your car. Each plays a critical part in keeping its system operating safely, efficiently and for a long time.
An overused furnace filter loses its effectiveness, allowing potentially harmful particles to circulate through your home. It also slows airflow, which can damage your furnace and decrease its life span.
Ensuring your furnace uses a clean filter that is suitable 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 pros at Service Max Heating & Air Conditioning. We've long focused on enhancing indoor air quality in Arlington. Here, we’ve answered common questions about HVAC filters, including that very 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 routinely. Dirt-clogged filters cause the system to worker harder than it should because it takes more energy to pull air through the plugged-up filter.
Officials suggest inspecting your furnace filter monthly and replacing it if it’s dirty. You’ll know if your filter needs changing because it will be gray or black from dirt or dust. Those who have pets that shed will very likely need to replace their furnace air filter more often, because a good 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 normally located 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 moves through the furnace components and is heated.
Depending on the furnace model, the filter may be positioned on the right, left, bottom or in some cases, on the inside of the furnace. It's usually housed within a slot, frame or cabinet for simple access and replacement. Always refer to your furnace's owner manual for facts about filter location of the furnace in your home.
Are Air Filters and Furnace Filters the Same Thing?
The easy answer is, yes. In HVAC, a furnace filter and an air filter or air conditioner filter are basically the same thing. While they might be called different things based on the current season— summer or winter—they are all filters that clean the air in your HVAC system.
They each get rid of dust, allergens, bacteria and other contaminants from the air that is drawn into the furnace and air conditioning system, making sure the air distributed throughout your home is clean and safe.
What Are MERV Ratings and What Rating Is Best for Me?
Once you locate your old furnace filter and figure out when it should be changed, it’s time to pick 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 stands for Minimum Efficiency Reporting Values. The MERV rating indicates the effectiveness of air filters at trapping airborne particles. The rating scale ranges from 1 to 20, with higher numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers a good balance between having healthy indoor air quality without unnecessarily restricting airflow. However, people with some health conditions might need a a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or AC Unit
Putting an air filter in a furnace or air conditioner properly is important for the efficient operation of the heating or cooling system. Air filters are designed to be installed in a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be placed in the unit with this arrow pointing at 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 conditioning unit.
Many people have difficulty remembering which direction to face their air filter. To help remember, consider taking a quick picture with your mobile phone after the filter has been properly 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 do this is during a regular furnace maintenance appointment.
How to Change a Furnace Air Filter
Switching out the filter on your furnace or AC is a quick and easy process. Here is a step-by-step breakdown of how to retreive a dirty air filter and replace it with a new one:
- Turn off your furnace: Be sure to switch off your furnace before beginning the process.
- Find the furnace filter: Typically, the filter is located 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 in the same direction.
- Take out the old filter: Be diligent not to knock out any dust or debris.
- Document the date: Write down the date you changed filters on the new filter's frame. This will help your family 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 toward 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 correctly and close any latches or clips that lock it in the unit.
- Turn on your furnace: Once the clean filter is properly installed, you can turn your furnace back on.
Will a Dirty Air Filter Cause Problems for a Furnace?
The shortest answer is, yes, a dirty air filter can cause a furnace to quit working or shorten its lifespan. Changing your furnace or AC filter is one of the simplest things you can do to keep your system working efficiently.