Selecting the correct 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 crucial function in keeping its system operating safely, efficiently and for a long time.
A dirty furnace filter loses its effectiveness, permitting potentially harmful particles to flow through your home. It also limits airflow, which can damage your furnace and shorten its life span.
Ensuring your furnace uses a clean filter that is suitable for your needs is not just about keeping your furnace working efficiently. It’s also about creating healthy indoor air quality for your home.
The quality of the air your family breathes is important to the HVAC professionals at James Heating & A/C, Inc. We've long worked with an eye on improving indoor air quality in Lexington. 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
Experts stress it's important 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 extra effort to pull 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 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 usually found 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 passes 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, inside the furnace. It's generally housed within a slot, frame or cabinet for easy access and replacement. Always refer to your furnace's owner manual for details regarding filter location of your furnace.
Is a Furnace Filter the Same as an 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 they might be called different things based on the current season— warm or chilly months—they are all filters that clean the air in your HVAC system.
They each get rid of dust, allergens, bacteria and other particulates from the air that is drawn into the furnace and air conditioning system, ensuring the air distributed throughout your home is clean and safe.
What Is a MERV Rating and What MERV Rating Do I Need?
Once you find your old furnace filter and figure out when it should be replaced, it’s time to pick a replacement. That means deciding on the level of filtration that you need. One method to do this is by choosing an appropriate MERV rating for your needs.
MERV stands for Minimum Efficiency Reporting Values. The MERV rating measures the effectiveness of air filters at trapping airborne contaminants. The rating scale ranges from 1 to 20, with bigger numbers indicating enhanced capabilities to filter tinier particles.
Experts say a filter with a MERV rating between 8 and 13 offers an appropriate balance between having adequate indoor air quality without overly restricting airflow. However, people with certain health conditions might need to purchase a filters with a higher MERV rating.
Which Way to Put the Air Filter in a Furnace or Air Conditioner
Putting an air filter in a furnace or air conditioner properly is crucial for the efficient operation of the unit. Air filters are supposed to face a certain direction, indicated by an arrow written on the side of the filter frame. The filter should be installed with this arrow pointing in the direction of the furnace or AC, which is the direction of the airflow. If you're doubtful about the airflow direction, 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 struggle with which direction to face an air filter. To help remember, consider taking a picture with your mobile 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 perfect time to do this is during a scheduled furnace maintenance appointment.
How to Change a Furnace Air Filter
Replacing the filter on your furnace or air conditioner is a quick and easy process. Here is a step-by-step list of how to retreive a dirty air filter and replace it with a new one:
- 1. Turn off your furnace: Be sure to shut off your furnace before starting up the process.
- Look for the furnace filter: Typically, the filter is positioned 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 clean filter to point similarly.
- Remove the old filter: Be diligent not to knock out any dust or debris.
- Note the date: Write down the date you replaced the filter on the new filter's frame. This will help your family keep track of when it's time for another replacement.
- Put 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 your last filter.
- 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 clean filter is safely in place, you can turn your furnace back on.
Will a Dirty Air Filter Cause a Furnace Not to Work?
The shortest answer is, yes, a dirty air filter can cause a furnace to cease working or shorten its lifespan. Changing your furnace or air conditioner filter is one of the simplest things you can do to keep your system working correctly.