How often to change air filter at home? 20-180 days + best practices

HVAC air filters are not made to last forever. They need to be changed regularly; Everybody knows. important question ‘How often to change the air filter in your home?’,

As you can imagine, the answer to how often an air filter should be changed is not one size fits all answer, You have to change your filters somewhere Between 30 days and 6 months (with the exception of holiday homes). how often to change the air filter Correct,

how often to change air filter at home
You will have to replace them if the filters are ‘dirty’. If you have to do this every 30, 60, 90 days, and so on, depending on the 7 factors below. You’ll also find a simple table with recommended air filter replacement times based on these factors.

Well, you might not want to replace them every 30 days if you don’t have to; Which would require 12 filter replacements per year. If you want to change the air filter frequently, you don’t want to change the air filter every 6 months (2 times per year).

not changing my MERV-rated Regularly enough air filters can increase the risk of allergies, HVAC system or furnace failure, and more in your home. So, for example, it is very important to change the furnace filter frequently. On top of that, you will of course have to pay high energy bill If you don’t change the air filter often enough.

Here’s the deal:

we hate to hear “depends on” from HVAC experts but in this case, it’s really impossible to say “HVAC and furnace air filters need to be replaced every 3 months” With any kind of certainty.

Below you will find a brief summary table of how often it is recommended to change an air filter in a home (with several days/months for most homes).

Let’s first look at the factors that affect how often you should change the air filter in your home:

7 factors that determine how often a home air filter should be changed

How often an air filter needs to be changed regularly depends on several factors, including:

  1. Filter type. cheap fiberglass filter Needs to be changed every 30 days. too expensive pleated air filter need to be replaced every 90 days, The MERV rating does not significantly affect how often the air filter in the home should be changed.
  2. domestic animal (cat, dog, etc.). Cats and dogs produce major air pollutants such as air dander, pet hair and fur. These can clog an air filter very rapidly and will reduce the time taken by how long an air filter can be left unattended for up to 1 month. More than 1 pet (or a large bloated dog) will reduce that time even further.
  3. children at home. With young children, you also need to be sure that they breathe as clean air as possible. Therefore it is recommended to change the air filter as often as every 2 months in a household with children.
  4. house size. In general, large house air filters are very rarely distributed throughout the house. This means that each air filter needs to filter more air (e.g. above 300 CFM) than a small house and it gets dirty quickly.
  5. Allergies. If you or someone in your home is prone to allergies, you should change the air filter regularly. The most common recommendation is to change the filter every 20 to 45 days if a person with allergies lives in the home.
  6. indoor air quality. In homes with below average indoor air quality, you will need to replace the air filter regularly. This is because because of the higher-than-average concentrations of indoor air pollutants, filters have to work extra hard to filter them out and reach their capacity quickly.
  7. The level of air pollution around your home. If you live on a busy street or near a factory, every time you open a door or window, you will be allowing air pollutants to enter your home. In this case, it is usually better to replace the air filter 1 week in advance.

As you can see, it can be hard to pinpoint how many times per year an air filter should be changed. We’re going to make it simple.

Here are best practice recommendations for how often to change the air filter in the home:

General ‘how often should you change your air filter at home’ recommendation

We can best estimate how often a household air filter should be replaced based on the 7 factors listed above.

As you can see from the table above, once per year in non-occupied suburban homes with pets it is enough to change the air filter. (every 12 months), When we add pets, people, city center locations etc, you have to change the filter more often (down to 20 days),

Here is the full table along with recommended air filter replacement times for pleated air filters:

Home Status: How often to change filter? Comment:
Unoccupied suburban homes without pets each 12 months Without occupants, you may be less concerned about indoor air quality
occupied suburban house without pets each 90 days No pets = no danger, suburban = no busy roads
House with 1 pet (dog, cat) each 60 days Large pet dander clogs the filter quickly
House with 2+ pets (dogs, cats) each 30-55 days More pets equals more pet dander
apartment in city center each 45 days Air quality in city centers is worse than in suburban areas
allergy-prone person or home with children each 20-45 days With Allergies, You Need Higher Indoor Air Quality

These are general recommendations. It makes sense to check what kind you have so that you know more precisely how often to change the filter.

In practice, it is always best practice to check how dirty your home air filter or furnace filter is from time to time. When you start to see brown dust accumulating over the entire surface of your home air filters, it’s time to replace them.

We hope this helps a little.


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