Most people know that air filters need to be replaced on a regular basis, but many don't know how to tell when their air filter is dirty and needs to be replaced. What does it look like when a filter needs to be replaced? When should you replace an air filter? In fact, a lot of people are curious if air filters have a shelf life or expiration date.
Air filters are used for a variety of different purposes. They remove dust, pollen, mold spores, and other airborne particles from the air you breathe. Some air filters are designed to also remove smoke, gases, and chemicals from the air. They are used in combination with air cleaners, but often other appliances utilize them. Air conditioners, heating units, vacuum cleaners, and humidifiers all use air filters to sterilize your breathing air.
Air filters come in a variety of shapes and sizes, but they all have one thing in common: they need to be replaced regularly. The frequency with which you need to replace your air filter depends on a few factors, including the type of air filter you have, the size of your home, the number of people in your household, and whether or not anyone in your home has allergies—to name a few.
Air Filter Expiration
Do air filters have a shelf life? It's a common question people ask. They might wonder what ingredients are used to make air filters or if any chemical solutions are used in the process. This is especially the case if people want to stock up on air filters for the next several years. Is it okay to do that?
Yes-- air filters can be kept in storage for years and function like new. Air filters have no ingredients that "expire", and most are not biodegradable. Furthermore, no chemicals or solutions are used. You can store air filters in a dark, temperature-controlled environment for as long as you want to.
That said, every filter is unique and the indicators for when its time to replace the filter is going to vary. So how do you know if you can keep using an air filter or if it's time to toss it? There are a few factors at work.
- Size of home or office
- Number of people in your home/office
- Frequency in which the air filter is used/unit is running
- How much pollution is present (smoke, smog, wildfires, etc.)
Disposable Vs. Reusable
If you have a disposable air filter, you will need to replace it more often than if you have a reusable air filter. Reusable air filters can be cleaned and reused, but you will still need to replace them eventually. The frequency with which you need to replace or clean your air filter also depends on the type of air filter you have.
Filter Material
There are three main types of air filters: HEPA filters, carbon filters, and pleated or fabric filters. HEPA filters are the most effective at removing airborne particles, but they need to be replaced more often than carbon or pleated filters. Carbon filters are good at removing smoke, gases, and chemicals from the air, but they need to be replaced every few months. Pleated or fabric filters are the least expensive type of air filter, but they need to be replaced every few weeks.
HEPA filters are made of fiberglass and will never expire, but cannot be reused.
Carbon air filters do not have an expiration date, but they will eventually stop working. Carbon air filters need to be replaced every three to six months, depending on the size of your home and the number of people in your household.
When Does An Air Filter Get Dirty?
So, how do you know when it's time to replace your air filter? The best way to tell is by looking at it. A dirty air filter will be darker in color than a clean air filter. It will also be clogged with dust, pollen, and other particles. If you can see through the air filter, it's time to replace it.
A mildly dirty filter still has room left to collect new particles. Surely you don't want to waste an air filter, but overusing it can cause more harm than good. If you're not sure when to replace your filter, here are some physical indicators that it's time:
The Light Test
When you replace HEPA filters for air purifier, try holding it up to a light source (sunshine or lamp both work.) With a brand new HEPA filter, you are able to see the light pass right through it. The less light that shines through it, the dirtier it is. So, it may be okay to keep using a mildly dirty filter. But, if you cannot see any light pass through it, it's time to toss the filter.
The Airflow Test
If you have an air purifier with a HEPA filter, you can test the airflow by holding a piece of tissue paper up to the air outlet. If the air is blowing strongly enough to move the tissue paper, then the filter is still working. If the air is not blowing strongly enough to move the tissue paper, then it's time to replace the filter.
Air Quality
Another way to tell if your air filter needs to be replaced is by monitoring your air quality and respiratory health. If you notice that your air is not as clean as it used to be, or if you're starting to experience more allergies or respiratory problems, it's probably time. There is more urgency to change the filter in the spring and summer seasons.
The Best Time to Replace Air Filters
The best way to know when to replace your air filter is to check it monthly and write the date you checked it on the air filter itself. This will help you keep track of how often you need to replace your air filter.
If you have a disposable air filter, you should replace it every three months. If you have a reusable air filter, you should clean it every month and replace it every six months.
Regularly checking and replacing your air filter is the best way to keep your air quality high and your family healthy.
