Guide: How Often Do You Change Air Filters?

Being a homeowner comes with many responsibilities that you must carry out at the appropriate time to maintain your property. One such responsibility is replacing your HVAC (heating, ventilation, and air conditioning system). Chances are high that your air filter is overdue for a change.

How Often Do You Change Air FiltersView in gallery

Air filters are not designed to last forever, meaning you have to keep track of the date when you installed them, so you can know when it is time for a replacement. If you take too long to replace your filter, it can get overloaded and collapse, causing more problems for your HVAC equipment and your comfort.

A collapsed air filter can get lodged in your fan or make a big gap, causing air to float around the filter without it getting filtered. If your filter is not filtering the air, it can have adverse issues on your health and cause breathing problems, especially for people with pre-existing conditions.

How Often Should You Change Your Air Filter?

Now that you know one air filter isn’t going to last you for life, you need to ask the critical question, how often should you change your air filter?

Determining when to change your air filter can be a little tricky for a couple of reasons. Every home’s design is slightly different, automatically resulting in a different answer each time the question of air filters is raised.

The type of filter you purchase can also factor in how often you replace this essential equipment. Typically, it is recommended that you change your filter every 30 days for cheaper fiberglass filters and anywhere from 6 months for higher-end pleated fibers. However, these recommendations may not be the best idea if you have allergies, asthma, or live with pets.

When you purchase a new filter, the packaging will indicate how long it is expected to last. Still, the filter’s expiry date should be the maximum date to which you keep that particular filter in. you should change your filter earlier than the packaging suggests.

Even though the answer varies from home to home, you must get to know what works for your family to keep your filter functioning properly.

A lot of factors are to be considered when determining how frequently your filter needs to be changed. Some of them include:

Asthma or Allergies

You should change your home filter more often if you suffer from allergies or asthma. Respiratory issues make you much more sensitive to airborne particles, so you should change your air filter every six weeks to ensure your indoor air quality remains at its best.

If you allow excess dander, dust, and other contaminants to accumulate in your filter and find their way into your home, it can affect you negatively. Symptoms like terrible coughs, runny noses, sneezing, and others you would instead do without clogged air filters can result.

Seasonal Changes

During flu and allergy seasons, you should upgrade your filters to high-efficiency filters. When you begin to observe an increase in air particles or pollutants, your air filter should get changed more frequently.

Also, during renovations, there is a likely chance that the amount of dirt and dust circulating in the house will increase and block up your filter. In such a situation, your home will require a more frequent filter change.

Tip- If you notice that you need to vacuum your house more often than usual, it might be a sign that you need to check your filter a lot more than you usually would.

How often to change air filter sprayView in gallery


Having pets can influence how frequently you change your air filter. Pets cause an increase in dander, fur, and dust floating through the air in your home. These pollutants come together and end up blocking the flow of air in your filter.

If you have multiple pets, it can get even worse, and the build-up of fur, dust, and dander can impede the running of your HVAC.

You should consider replacing your air filter every four to six weeks if you are a pet owner.

House Occupancy

When your house is a vacation home where you only spend a small amount of time yearly, the rules are different. Due to the absence of human activity during certain, fewer contaminants get trapped in your air filter.

The fewer the contaminants, the less often you need to change the air filter. You can prolong the periods between a filter replacement to a significant extent. Most times, vacation homes get a change in air filters every six months.

You can also pull off changing your air filter less frequently if you live alone and have no pets. The fewer people in a house, the less time it takes to clog your air filter.

Why Should You Change Your Air Filter?

Your house’s heating and cooling system have an essential role to play in the overall comfort of your home. You do not want to experience the sweltering heat of summer without the convenience of air conditioning.

However, you might still be tempted to ask, what difference does it make if I change my filter regularly or not. If you still are not convinced that regularly your air filter is a great idea, here are some reasons you should replace it regularly.

Cut Repair Costs

Over time, your air filter accumulates dirt, dust, fur, and other contaminants that may be found around your home. Your once new, white, and clean air filter will turn dusty and grey as it begins to spend months fin the return. This deterioration can have negative impacts on your HVAC system.

Changing your air filter is beneficial to the smooth working of your HVAC system. A dirty air conditioner can lead to the HVAC system undergoing extra work.

As time goes on, the strain on your unit will result in essential repairs or, even worse, cut short the lifespan of said unit. Changing your air filter will help keep the parts of your air conditioner clean, preventing it from wear and tear. You can save yourself money by simply changing your air filter routinely.

Conserve Electricity

During the summertime, your electricity bill can go up in astronomical proportions. Changing your air filter can help you cut down your bill.

When your air filter is clogged, the HVAC unit requires a lot of extra work to circulate fresh air throughout your home; the extra work calls for more electricity. More electricity means more bills.

Replacing your filter will help you reduce the amount you pay for electricity. Investing in a relatively inexpensive air filter and replacing the filter at the right time can save you a lot of money in repairs.

Better Air Quality

Studies have shown that the air in your home can be as much as two to five times more polluted than the air outdoors. This can lead to many symptoms that you may never even trace to your HVAC system’s overall working.

If you get headaches frequently when you are cooped up inside for long or suffer from severe allergies when you encounter low indoor air quality, it could result from dirty air filters.

When your air filter is clean, you do not have to breathe in particles and other different contaminants. This will ultimately result in a healthier, higher quality life.

How often to change air filter sprayView in gallery

How Do You Know It’s Time to Change Your Air Filter?

An air filter’s job is to trap dirt, so any use of the filter will lead to its accumulating dirt. The big question is, how do you determine your filter has trapped more than enough dirt and requires a change?

There is no specific guideline, but if your filter has only a small layer of dirt and the filter material is still visible beneath it, your filter is fine. The moment it gets more than that, it is time to change out the filter. If you cannot see the filter material due to dirt becoming thick enough to cover most of the filter’s surface, it is a sign that your HVAC has housed the filter for too long.

You should inspect your air filter every week. If you notice a musty smell or that the filter is covered in dust change it. Filters are relatively inexpensive, so if you doubt, it is always better to replace it earlier than let it wait too long.

How to Change Your Air Filter

Replacing an air filter is a lot easier than you might think. It is a very straightforward process if you follow the following steps:

  1. Ensure that you turn off your HVAC system before you begin; this is very important.
  2. Find where your air filter is – you will most likely find your air filter where the air is sucked back from your home into your system (this is known as the return), which is either on your ceiling or wall with a grille covering it. If you do not find it there, it will be where your air handling unit is located, typically in your attic, basement, or closet. You will observe a small box that takes air into the unit.
  3. Take out the grille or open the box – if you own a grille, you will most likely find tabs that you can pull up, so you can take out the filter without needing a screwdriver.
  4. Locate the filter – the filter should carry the size or a model number printed on it to help you identify it and purchase the correct one. Ensure that you buy the correct size of the filter.
  5. Take out the dirty filter – observe the old filter when you take it out. If it is more contaminated than usual, this means you should change your filter more often than you already do. Please take note of gaps in the filter as these are a sign that your filter is too small, and you need to replace it with a bigger one.
  6. Put in your new filter, close the box, or put back the grill – this is the final step. Make sure you note the date when you change your filter to keep track and know when next to change the filter. 

How to Buy a New HVAC Filter

You probably know that you can find important information such as size printed on your current filter. However, you might still be unsure about what type of filter to purchase. Here are a few tips that can be of help:

  • Avoid buying the cheapest filter you can find
  • You should buy a pleated filter with a sturdy wire mesh supporting it and preventing it from collapsing.
  • Ideally, your filter should not have a very high MERV (minimum efficiency reporting value) rating. A quality filter should have a MERV rating above eight or nine. This type of filter will take out most of the small particles that can trigger allergies and other respiratory issues.

If you still feel unsure about picking a filter yourself, you can always seek professional help.

The MERV Scale; How to Rate an Air Filter

For most people, the most challenging part of changing your air filter is figuring out what kind of replacement you should get. This is why most companies refer to a particular scale while measuring the efficiency of their air filters. This is called the MERV scale.

The Minimum Efficiency Reporting Value scale gives professionals a uniform standard to use when rating their air filters’ quality. The MERV is measured by exposing a clean air filter to different sizes of particles. Each size of the particle is then forced through the air filter six times using a sprayer. About twelve other particles are used to determine which filters are best at trapping different air pollutants.

Based on this scale, there are sixteen different categories your air filter can belong to, these are:

MERV 1-4

These are the lowest ratings on the scare, and they trap the least number of contaminants from the air in your home. MERV 1-4 filters can trap common particles such as carpet fibers, dust mites, pollen, etc. from the air.

Like their price point, their efficiency is extremely low. This filter class is excellent for homes on a budget where there are no occupants with respiratory problems.


MERV 5-8 filters are a bit more effective than those in the MERV 1-4 category. They can work effectively in mold, finer dust such as cement, and even aerosol spray particles. Such filters are of higher quality and cost more than the primary category.

However, you should know that these filters are unable to trap particles smaller than one micron.

According to experts, you should get an air filter with a MERV score from 6 to 8 for the best performance. These filters are affordable and allow your HVAC system to function conveniently without any strain. When your unit operates smoothly, it keeps your bill as low as possible while keeping excellent air quality.

MERV 9-12

This class of filter is considered very high efficiency. It can trap tiny particles from the air, as little as auto emissions. If you use filters in this category, your HVAC system has to do some extra work to circulate cooled air in your home. The weave of the air filters that fall in this class makes it a lot more difficult for the HVAC system to function seamlessly.

MERV 9-12 filters are perfect for people who have allergies; the downside is that it may negatively reflect your electricity bill.

MERV 13-16

A filter of this rating is classed maximum efficiency. They are more suited for commercial buildings than a home heating and cooling system.

The filters in this group can filter particles as small as 0.3 microns, such as tobacco smoke and bacteria.

Other Considerations

Here are a few other things you might want to consider when buying an air filter:


The return sizes differ from home to home so ensure you check the size of your current filter so you buy the right fit.


If you do not particularly fancy the idea of having to throw out your air filter after every few weeks or months, you might want to invest in a washable air filter. Although this may be extra work for you, it is environmentally friendly.

Using a washable filter is also beneficial because you can change it as regularly as you like while still saving money on air filters. Washing your filter on a more regular basis will increase the quality of air inside your home.


The more pleats an air filter has, the higher the chances of removing air pollutants from your indoor air. In situations where you cannot find the MERV rating on the air filter packaging, you can lookout for a filter with a lot of pleats per foot.

Pleats are a great way to gauge the overall efficiency of an air filter.


You must know what to expect when it comes to changing your air filter. Each home has different needs when it comes to HVAC so remember to consider your lifestyle and the rate of occupancy in your home when replacing your air filter.

Your HVAC’s lifespan and health will be grateful to you if you adhere to the proper guidelines regarding how frequently you should change your air filter. Check your air filter today, replace it if it is overdue and enjoy fresh, clean air in your home.