In this article…
- What Air Filter Sizes Are There?
- Which Filter Size Is Right for Your System?
- Where to Locate the Air Filter in Your HVAC System
- How to Replace Your Air Filter
- Maintaining Your HVAC System For Optimal Performance
One of the easiest (but possibly most neglected) maintenance you can do for your HVAC unit is changing the air filter.
Air filters play a crucial role in maintaining your HVAC system’s efficiency and the overall air quality in your home. The right air filter not only ensures that your system works smoothly but also contributes to cleaner, healthier indoor air.
A simple task that takes less than five minutes to do can still be daunting – you may not even know where to start and may be wondering…where is my filter located? What size filter do I need? How do I change it?
Don’t worry. We’re here to help.
Wright Home Services has been a trusted HVAC service company in San Antonio since 1979, helping thousands of homeowners keep their homes comfortable and educating them on all things heating and cooling.
HVAC maintenance doesn’t have to be difficult, and there are several things you can do that don’t require professional assistance but can drastically improve the efficiency and lifespan of your system. Regularly replacing your air filters is one of them.
This article will outline how to properly replace your AC filters, from finding the right filter size to locating where it goes, so you can know how and when to replace your filters and keep things flowing.
What Air Filter Sizes Are There?
Air filters come in various sizes and thicknesses, and choosing the right one is key to optimizing your HVAC system’s performance.
Air filters are typically labeled with dimensions such as 16×20, 20×25, or 16×25 and come in one to two inches thickness. These numbers represent the length and width of the filter in inches.
Here’s a breakdown of how to understand filter sizes.
- Width and Height: The first two numbers correspond to the width and height of the filter. For instance, a 20×25 filter is 20 inches wide and 25 inches tall.
- Thickness: The third number, often referred to as the “depth,” represents the filter’s thickness. Common thickness options include 1″, 2”, 4″, and 5″. Thicker filters tend to offer better filtration, as they can trap more particles and last longer before needing to be replaced.
It’s important to understand that air filter sizes are standardized, but they can vary depending on the manufacturer or the specific needs of your HVAC system.
Using the right-sized filter ensures that the airflow is optimized and prevents the system from being overworked, shortening the lifespan of your system.
Which Filter Size Is Right for Your System?
Knowing how to select the proper filter size for your HVAC system can save you time, money, and frustration, and figuring out which filter size you need isn’t difficult.
Here are the main ways to determine which filter size you need:
1. Check the Existing Filter
If your system already has an air filter installed, it’s likely the right size for your system. Simply remove the filter and look for the size printed on the frame.
The size is typically listed in the format of width x height x thickness. For example, it may say 20x25x1, which means the filter is 20 inches wide, 25 inches tall, and 1 inch thick.
2. Consult the HVAC Manual or Manufacturer’s Guide
If you can’t find the size printed on the existing filter, the HVAC system manual or manufacturer’s guide will usually list the recommended filter size. This can be helpful if you’re unsure or if you’ve recently installed a new system.
3. Measure the Filter Yourself
If you don’t have any dimensions to go by, you can easily measure the filter yourself. Use a tape measure to measure the width, height, and thickness of the filter slot or the filter already in place.
Make sure to measure accurately to avoid the frustration of buying a filter that won’t fit.
Why the Right Size Filter Matters
Choosing the correct filter size is essential for several reasons, all of which affect your HVAC system’s efficiency and the air quality in your home.
Here are some of the top reasons why using the right size filter matters.
1. Airflow Issues
The air filter’s job is to trap dust, dirt, and other particles before they enter your system. If the filter is too large, it may not fit properly in the slot, which can restrict airflow.
On the other hand, a filter that’s too small can leave gaps around the edges, allowing debris to bypass the filter and enter the system, reducing its effectiveness.
2. System Performance and Longevity
An incorrectly sized filter can make your HVAC system work harder to circulate air. This can lead to more frequent breakdowns, requiring more frequent repairs, and ultimately shortening the lifespan of the system.
3. Energy Efficiency
When the HVAC system has to work harder to circulate air through an improperly sized or clogged filter, it uses more energy.
This not only increases your utility bills but also puts unnecessary strain on the system, leading to higher maintenance costs.
4. Indoor Air Quality
A well-fitting filter does a better job of trapping dust, pollen, and other airborne particles, improving the air quality in your home.
A filter that’s too small or too dirty won’t be as effective in capturing these pollutants, which can increase the discomfort of allergies and respiratory conditions.
Where to Locate the Air Filter in Your HVAC System
Now that you understand why the correct filter size is important, it’s time to figure out where to find the filter in your system. The location of your air filter will depend on the type of HVAC system you have (horizontal or upflow).
Here are the most common places to find the filter:
1. Return Air Vents
In most homes, the air filter is located in the return air vent, where air is drawn into the system before being heated or cooled. Return vents are usually found on walls or ceilings, especially in living rooms, hallways, or entryways.
To locate the filter, simply remove the vent cover and check for a filter inside the vent.
2. Furnace Compartment
For systems with a furnace, the filter is often located where the air enters the furnace compartment. This is typically a large metal box where the air is heated before being distributed throughout the home.
To access the filter, open the front panel or the filter access panel. Depending on the model, the filter may be located on the side or bottom of the furnace.
3. Air Handler or Blower
Some HVAC systems have an air handler or blower unit, which circulates air throughout the home. In these systems, the filter can be located where the air enters the air handler or blower compartment. Again, the filter is usually accessible by removing a panel or door.
It’s important to know exactly where your filter is located so you can regularly change your filter on a timely schedule, keep your air clean, and maintain the efficiency of your system.
How to Replace Your Air Filter
Replacing your air filter is a straightforward and simple task. Here’s a simple step-by-step guide:
1. Turn off your HVAC system
Before replacing the filter, turn off your HVAC system to prevent it from running while you’re working.
2. Remove the old filter
Carefully remove the old filter from the compartment. Remember to pay attention to the orientation of the filter to then insert it in the correct direction. There’s usually an arrow on the side of the filter that indicates the direction of airflow.
3. Install the new filter
Insert the new filter into the same slot, making sure it’s properly aligned. Ensure that the filter fits snugly and is seated correctly.
4. Turn the system back on
Once the new filter is in place, turn your HVAC system back on and check for proper airflow.
How Often Should You Change Your Air Filter?
How often you should change your air filters depends on the size and thickness.
- 1” filters should be changed every 30-60 days
- 2” filters should be changed every 60-90 days
- Media filters or 4”/5” filters should be replaced every 6 months but can last up to a year
However, several factors also affect how often you should replace your filters.
For example, if you have pets, live in a dusty area, or suffer from allergies, you may need to change the filter more often. Similarly, if you use a high-efficiency filter, you might be able to go longer between changes.
Regularly changing your air filter is essential for maintaining both system efficiency and indoor air quality.
*Setting a reminder on your smartphone to check your filter every month and replace it as needed is an easy and affective way to maintain your system.
Maintaining Your HVAC System For Optimal Performance
Now you have all the knowledge you need to properly locate and replace your HVAC filters with the proper filter size and can continue to maintain your system for optimal efficiency.
Regularly inspecting and replacing your air filters is one of the easiest ways to maintain your system and keep it functioning properly.
If you leave your filters in too long and don’t change them regularly, the build-up risks increased dust and debris in your home, puts excess strain on your system, and can create more problems in the future if left unaddressed.
Locate your filter chamber on your system, ensure you buy the correct replacement size, and return the new filter in properly to mitigate dust, dander, and pet hair circulating throughout your home.
Want to learn more about the importance of replacing your air filters and why they should be replaced? Check out this article and video to learn more from Wright Home Services!
