How long does an ac filter last

How often you change your home’s HVAC air filter depends on how long your filter is expected to last and the different qualities of your home that impact the filter. When in doubt, call A-1 Mechanical for expert advice and indoor air quality services for your Michigan home.

How Long Do Air Filters Generally Last?

As mentioned above, there is no set service life for an air filter – it requires an evaluation of many different aspects. Air filter manufacturers include a recommendation for how often to change air filters. You can find this information on the product insert that comes with a new filter. Furnace filters are expected to last anywhere from one month to one year.

• 1-inch and 2-inch air filters should be replaced about every one to three months
• 3-inch and 4-inch filters require replacement after six to nine months
• 5-inch and 6-inch air filters need a change after nine months to one year

Factors Affecting How Often to Change HVAC Air Filters

The manufacturer’s recommendation isn’t the final answer on how frequently you should change your furnace filter. The biggest factors affecting filter service life are detailed below.

Pets in the Home

Indoor pets shed hair and dander that easily become airborne in your home. These materials clog air filters faster. Homes with one pet should generally replace filters after two months; those with more than one pet may need to replace the filter monthly.

Heating & Air Conditioning System Use

How frequently your heating or air conditioning system is in use impacts filter service life as well. During periods of the year when HVAC equipment runs often, air is circulated more times through the home compared to times when the HVAC system is used sparingly. More cycles mean more passes through the filter and opportunities to trap contaminants, so filters typically fill up faster during high-use periods. 

At the peak of summer and winter, air filters need to be changed more frequently than required during the spring, fall and the milder months.

Allergy & Asthma Sufferers

If there are allergy or asthma sufferers in your household, clean air is critical to their health and comfort indoors. You’ll need to change your HVAC filter more frequently when allergy and asthma sufferers are present. Changing the filter on a more frequent basis ensures the filter has the available surface area needed to filter out the contaminants that trigger symptoms among your loved ones. 

Have Questions? A-1 Mechanical Is Here to Help!

Estimating how often to change an air filter can be tricky because of so many different variables at play. If you’re unsure how often your furnace filter requires replacement, call A-1 Mechanical! Our knowledgeable team of NATE-certified HVAC system technicians is always available to assess the indoor air quality needs of your home and help you create a plan for cleaner air indoors, from an accurate filter replacement schedule to installing advanced filtration solutions.

Replacing the filter in your air conditioning and/or heating system regularly keeps your appliances working properly and your energy bills low. It's also a task that many homeowners forget about for months at a time, which can send your energy bill skyward and potentially contribute to other maintenance issues down the line. Read on to find out the best rate at which to change your air filter!

General Recommendations

So, how frequently should you change your air filter? The answers is: it depends.
Typical recommendations range from every 30 days for cheaper fiberglass filters (which often don't do a great job of filtering), to as long as 6 months for higher-end pleated filters. These estimates assume average use and take into account the type and size of your filter.

A general rule of thumb for pleated air filters (like ones made by FilterBuy) is to replace your filter every 90 days. As your filter traps more dirt, dust, and allergens from the air, filter efficiency decreases. Find out below if you should be replacing your filter more often.

Does someone in your home have asthma and/or allergies?

Those with asthma and/or allergies are much more sensitive to airborne particles than those without. If you have an asthma- or allergy-sufferer at home, change your filter every 6 weeks to ensure indoor air quality is at its best.

Does someone in your home have asthma and/or allergies?

Those with asthma and/or allergies are much more sensitive to airborne particles than those without. If you have an asthma- or allergy-sufferer at home, change your filter every 6 weeks to ensure indoor air quality is at its best.

Do you have pets?

Cats and dogs shed and have odors that can build up in your space, making it necessary to change your filter every 2 months. Generally, cats and dogs shed most when winter turns to spring and summer turns to fall, which are key times to replace your filter.

Do you have young children?

Superior indoor air quality is especially important with kids around. Keep your home clean and air quality under control by replacing your vacuum filter every 2-3 months.

Factors that can affect your HVAC air filter's lifespan include:

The rate at which you use your heating and/or cooling system

If you live in a temperate climate and use your heater and/or air conditioner up to a few hours every day, a single filter can last you from a whole season to an entire year. If your HVAC system is running on a near-constant basis, however, change your filter every few weeks (especially if you're using a cheaper fiberglass filter).

The rate at which you use your heating and/or cooling system

If you live in a temperate climate and use your heater and/or air conditioner up to a few hours every day, a single filter can last you from a whole season to an entire year. If your HVAC system is running on a near-constant basis, however, change your filter every few weeks (especially if you're using a cheaper fiberglass filter).

The size of your home

Furnaces and air conditioners in smaller homes need to pump less air for the same amount of temperature change, which may mean less frequent filter changes. These appliances are often built with smaller filters, though, and thus may need to be changed just as regularly as a filter in a larger home.

The air quality within your home

The air within or outside your home will also affect your filter's replacement cycle. Pets or poor air quality, for example, will require you to replace your air filter more frequently.

The air quality within your home

The air within or outside your home will also affect your filter's replacement cycle. Pets or poor air quality, for example, will require you to replace your air filter more frequently.

How to Tell When Your HVAC Air Filter Needs Changing

Any use will lead to some amount of dirt being trapped in your air filter - that's its job, after all.
So how do you know when your filter has trapped too much dirt and needs to be replaced?

There's no strict guideline, but if your filter shows only a subtle layer of dirt under which the filter's material is still visible, your filter is in fine working order. Once it gets much beyond that point, it's ready to be changed out. If there's a visible coating of dirt covering most of your filter's surface that is adequately thick to obscure the filter material itself, that's a sign that your filter has been in your HVAC system far too long.

Every few weeks, take out your filter and give it a look! Is there a musty odor? Is the filter covered in dust? If in doubt, it's always best to err on the side of replacing your filter. They're relatively inexpensive, and that small cost to keep your heating and cooling vents clear will be well worthwhile when your energy bill comes due. If it's been a while since you've changed your filters, we can help you find the right size, brand, and type of HVAC air filter for your furnace and/or air conditioner.

Ready to replace your filter? Click here and get your system back to clean efficiency!

FAQ

How do I know if my air filter needs changing?

There are often obvious signs that your air filter needs changing. They include:

• Dust and debris accumulating on your intake vents
• Dust and debris accumulating near your output vents, often on the ceiling and walls nearby
• Dust accumulating on fan blades, curtain rods, on top of cabinets, indicating that there is an excess of dust in circulation
• Noticeable loss of cooling power in your AC system
• Sounds of excessive strain when your AC system starts up
• Longer periods of run time for your AC system to cool to desired temperature
• Indicator on your AC controls telling you to change your air filter

When in doubt, buy a replacement air filter and change it out.

How long can you go without changing the air filter?

The longest you should go without changing your air filter is the recommended 90 days. However, if replacing your air filter is simply out of the question for an extended period of time, going beyond 90 days is not going to cause irreparable harm to your AC system. However, you will put unwanted strain on your HVAC system, resulting in poor air quality and air circulation.

What are the symptoms of a dirty air filter?

Symptoms of a dirty air filter can include:

• Dust and debris accumulating on your intake vents
• Dust and debris accumulating near your output vents, often on the ceiling and walls nearby
• Dust accumulating on fan blades, curtain rods, and on top of cabinets, indicating that there is an excess of dust in circulation
• Noticeable loss of cooling power in your AC system
• Sounds of excessive strain when your AC system starts up
• Longer periods of run time for your AC system to cool to desired temperature

Does changing the air filter make a difference?

Yes, changing your filter has several impacts on your HVAC system’s ability to cool your house and the overall quality of your air. When you change your air filter, you allow more air to flow through your system with less power usage resulting in better circulation, cleaner air, and a lower electricity bill.

How do you know when your AC filter needs to be replaced?

What happens if you dont change AC filter?

How long are AC filters good for?

How long can you go without changing AC filter?