How often should HVAC filters be changed?

Author: Dr. Aileen Bergnaum DDS  |  Last update: Monday, May 19, 2025

Generally, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days, or 3 months. That can change based on where your home is located (ex. dusty, dry climates), if you have any pets, and the age of your system and equipment.

How do I know when my HVAC filter needs to be replaced?

6 Telltale Signs It's Time to Replace Your AC Filter
  1. Accumulation of Dust Around the Air Vents. When an air filter clogs, it releases dust and dirt into the system. ...
  2. Strange Odor. ...
  3. Sudden Hike in Electricity Bills. ...
  4. Overheating AC Unit. ...
  5. Allergies. ...
  6. Malfunctioning AC.

Do you really need to change air filters every 3 months?

Changing your filters every 3 months is the way to maintain proper airflow, efficient operation, and great indoor air quality throughout your home.

What happens if you don't change HVAC filter?

If you don't change your air filter, it can quickly become clogged with dust and debris, preventing proper air filtration. This leads to a variety of issues for your HVAC system including system inefficiency, higher energy bills, inadequate air quality, and ultimately failure.

How long do 4 HVAC filters last?

A three to four-inch filter can last for six to nine months. If you have a thick five to six-inch filter, it can last from nine to twelve months. By making sure that your filters are changed when they need to be, you can enjoy having a heating and cooling system that will work its best.

How Often Should You Change Your Furnace Air Filters?

How long do 16x25x4 filters last?

As a result, it is important to change your 16x25x4 furnace filters at least every 3 months. You should also be aware of what types of 16x25x4 furnace filters are available and how often you need to change them based on their efficiency level.

How often should AC vent filters be changed?

Generally, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days, or 3 months. That can change based on where your home is located (ex. dusty, dry climates), if you have any pets, and the age of your system and equipment.

Can I clean my AC filter instead of replacing it?

Many disposable air conditioner filters should be replaced rather than cleaned, as cleaning with water can lead to possible mold issues. Clean the coils and fan of the AC regularly, using a canister of condensed air to blow away dust and buildup.

Is it bad to never change the air filter?

As the system is working harder to get around clogged air filters, it can cause the entire system to overwork and eventually break. If this happens, you'll need to replace the entire system, which can cost anywhere from $4,000 to $12,000.

Do I need to turn off HVAC before changing filter?

Turn off the AC unit.

Make sure to turn off your air conditioner once you're ready to replace the filter. This is important for two reasons. First, having the power on while working on appliances is not safe. Second, you don't want the system to suck in dust and debris while you're in the middle of changing the filter.

Do expensive air filters last longer?

Expensive air filters are made from higher-quality materials, like fiberglass, that can last for up to 12 months. This not only saves you money, but it's also more convenient since you won't have to remember to replace your air filters as often.

What is a good MERV rating for a carrier?

A good MERV (Minimum Efficiency Reporting Value) rating for residential HVAC systems is typically between 8 and 13. MERV 8 filters capture basic particles like dust, pollen, and pet dander and are adequate for most households.

How do I know if air filter needs changing?

7 Signs You Might Need to Replace Your Car Air Filter
  • Reduced Fuel Efficiency. The most common sign is a decrease in gas mileage. ...
  • The Engine Light Is On. ...
  • The Air Filter Is Dirty. ...
  • Jerking Movements When You Accelerate. ...
  • Misfiring and Starting Issues. ...
  • Strange Engine Sounds. ...
  • Black Smoke or Flames From the Exhaust Pipe.

How much do HVAC filters cost?

Filters with a MERV rating of 1 to 7 typically cost between $5 and $20. Filters with ratings of 8 to 13 can cost anywhere from $20 to $150. HVAC systems in residential homes usually don't need (and often cannot handle) filters with a MERV rating of more than 13.

Why is my air filter black after 2 days?

Black Soot Deposition

Black soot can quickly turn our air filters black. This is usually a result of burning candles. Candles are made of carbon-based materials that don't all combust when burned. They end up producing tiny soot particles which then get into our carpet, on our furniture, and in our air filters.

Is it OK to run HVAC without filter?

Never run an HVAC system without a filter. You can either turn the system off or run it sparingly until you replace the filter.

How much does an air filter change cost?

Replacing your car's air filter can cost anywhere from $20-$50, depending on the type of vehicle you have and the quality of filter. A high-quality filter will ensure better airflow, engine performance, and fuel economy — so it's worth investing in a reliable one!

Is no air filter better than a dirty one?

Is no AC filter better than a dirty one? No. A dirty filter will slightly protect against some dust particles that will damage your AC system. Its better to have a dirty filter than having no filter.

What happens if you don't change AC filters?

As previously discussed above, failing to change your filter means debris and dirt will soon clog your unit, causing it to overwork. This in turn raises your energy bills. It takes longer to cool your home. With an old air filter running, you'll notice that it takes so much time for your AC to cool you home.

What happens if you haven't changed your AC filter in a year?

Air filters that are overdue for a change are a common cause of HVAC system failure. Over time, dirt builds up in the heating and AC filters, causing components such as the motor to go into overdrive, which may eventually overheat your unit.

Can I vacuum my HVAC filter?

Taking care of your furnace filter is all part of regular maintenance. There are some key variables you will need to be able to keep your furnace filter going strong: Wash or vacuum the filter once a month.

Will AC stop working if filter is dirty?

Is my AC not working because of the filter? Potentially, yes. While there are a whole host of issues that could cause problems with your air conditioning system, a dirty air filter should be the first thing to check if your central air conditioning unit isn't working as properly as it should.

How do I know when to change my HVAC filter?

Visual Inspection. The only way to be sure about how often to change your air filter is to perform a visual inspection of the filter every month. After a few months, you'll get an idea of how quickly it becomes dirty. You'll need to re-evaluate if you get a new pet or if the outdoor air quality has been poor.

How many AC filters are in a house?

Essentially, most homes will have at least two air filters, because most homes have a return duct to go along with their air handler. Determining how many filters your home needs is a big step in helping improve your home's indoor air quality and keep you breathing easy.

How often should I change my oil filter?

Every Oil Change

In general, most newer vehicles are designed to run on 6,000 or 7,500-mile cycles for oil changes (the old 3,000-mile cycle is a myth in terms of newer vehicles). Most mechanics agree that it's just a smart idea to have the filter swapped out every time you take your car in for an oil change.

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