Asked by: Gerardo Ulshofer
home and garden indoor environmental quality

How long do 4 inch furnace filters last?

Last Updated: 14th January, 2020

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Rules of thumbs are 1 inch filters change at least every three months if not sooner, 2 inch filters 4 months, 4 inch filters can last 6 to 8 months and 5 inch filters can last as long as a year depending on the quality. If you can see dirt on your filter it is about 50% plugged.

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Also question is, how often should you change a 4 inch air filter?

A good rule of thumb is to change 1-2 inch filters every three months, 4 inch filters every six months and 5 inch filters every 12 months. Signs your air filter needs changed: The filter is visibly dirty. Certainly if you can't see the material of the filter itself, it should be replaced.

how long is a furnace filter good for? The general rule for filter replacement is once every 3 to 6 months. Thicker filters don't have to be changed as often, such as 6-inch filters, which can last between 9 to 12 months before they need to be replaced. For a loose frame of reference refer to this chart: 1″ Furnace Filter: 1 – 3 Months.

Also to know, are 4 inch or 1 inch furnace filters better?

While a 4-inch-thick filter is more efficient than a 1-inch filter, the right size depends on your furnace. If you measure the filter slot, and it's large enough to accommodate the thicker filter, then you can use it. However, if the slot is less than 4 inches wide, you're stuck with using that thickness.

How often do you change furnace filters?

every 90 days

Related Question Answers

Zhixiang Viuda

Professional

Can I use a 4 inch filter instead of 5?

No way! You just need the right kind of high MERV filter. A thicker filter (4-5 inches) has more surface area and therefore allows more room for air to pass through. Do this: If you're really interested in keeping your air clean, we'd suggest you get an air cleaner/purifier installed in your air ducts.

Tandy Benen

Professional

What happens if you dont change AC filter?

If you don't change your AC filter, it will begin to fail. It will no longer be able to filter the air properly, letting dust and contaminants get into the AC. Dust jams the moving parts of an AC such as fan motors and valves. This is how dust makes the unit less energy efficient.

Chandra Widmer

Professional

Do thicker furnace filters last longer?

Filter thickness: A filter's thickness can range from 1″ to 5″. As a general rule of thumb, a thicker furnace filter will last longer and can be more efficient.

Yizhong Klemcke

Explainer

Is a thicker air filter better?

Most air filters are 1 inch thick, but some systems can accommodate filters 2 to 5 inches thick. In our tests, we found that the thicker the filter, the better it works and the longer the replacement intervals. That means it's better for you and for your HVAC system.

Jeremi Serrado

Explainer

Does the type of air filter matter?

Air filters are all the same.
It's true! All air filters are not the same! Fine dust and dirt particles collect in the furnace's heat exchangers and cooling coils, blocking air flow. Home HVAC air filters are graded by their MERV rating with most home filters falling between 1 and 13 (13+ are for HEPA filters).

Roumiana Avignon

Pundit

How often should you change a 1 inch furnace filter?

Rules of thumbs are 1 inch filters change at least every three months if not sooner, 2 inch filters 4 months, 4 inch filters can last 6 to 8 months and 5 inch filters can last as long as a year depending on the quality. If you can see dirt on your filter it is about 50% plugged.

Nelia Pelicano

Pundit

Why is my furnace filter so dirty?

Your filter gets clogged faster when your furnace is running more often. That's because more air is cycled through your filter when your furnace goes through more heating cycles, so more contaminants get caught on the filter's media. The colder it gets outside, the faster your filter will get clogged with dirt.

Zina Wlodarczyk

Pundit

Is MERV 13 too restrictive?

MERV is a good way to help judge the effectiveness of an air filter. In some cases, using an air filter that is too restrictive for your system may cause low air flow problems as well. MERV 13 is the highest MERV value safe for residential furnaces; the higher ratings are used primarily in commercial units.

Aihnoa Nuncibay

Pundit

What happens if you put a furnace filter in backwards?

The most common problem you will face with a backwards facing filter is simple inefficiency. If your furnace is forced to blow air through the non-porous end of a filter, it will take more energy to do so. The blower will be overworked and you will pay more money for your heating.

Gigliola Lazcanotegui

Pundit

Are expensive filters worth it?

More expensive filters like Pleated Residential filters filter out dust mites, pollen, mold and pet dander and even bacteria and so are worth the money especially for those with severe allergies. HEPA filters filter bacteria and viruses and are worth the extra money for those with respiratory conditions like emphysema.

Nuria Kañabera

Teacher

Should I use MERV 8 or 11?

A MERV 8 filter should pick up most animal dander, but if you have 2 or more pets you may need a MERV 11 to completely eliminate those harmful particles from your home's air.

Niklas Garcia Gil

Teacher

Is it better to use cheap furnace filters?

Cheap fiberglass filters are designed to stop dust, debris and hair from gunking up the system. While they do little to filter out allergens and other irritants, using them keeps your HVAC system clean and efficient. They can add more resistance to airflow, which makes the system more expensive to operate.

Delfino Hoflich

Teacher

Does Merv 8 restrict airflow?

Because they restrict airflow to your HVAC system. Pleated, high-MERV filters definitely capture a lot of pollutants, but they also restrict the movement of air into your blower or furnace. When you need better filtration than what a 1" MERV 8 filter can provide, the best solution is to invest in…

Yanai Vyazmitinov

Teacher

Are MERV 11 filters too restrictive?

A decade ago, it used to be that if you had an HVAC system that used panel filters rated 6 through 9 MERV, putting in a MERV 11 or higher filter would restrict airflow (known as filter pressure drop). In turn, this would lengthen the system's run-time, adding to your heating and cooling costs.

Catherina Hennig

Reviewer

What MERV rating should I use?

Most residential HVAC systems will use air filters with MERV ratings from 7-12. A higher MERV value of 5-16 would be recommended for commercial buildings. In general, filters with higher MERV ratings have smaller pores through which air can pass, while still capturing allergens.

Nicodemus Membrilla

Reviewer

Can my furnace handle a MERV 13 filter?

MERV filters 1-4 are only good for blocking large particles from damaging your furnace. The ideal MERV filters for both air filtering and furnace efficiency are 7-13, experts say. These filters can be used without any modifications to your equipment. Your system may handle MERV 14-16 with no discernable stress.

Althea Usclade

Reviewer

Can you run your furnace without a filter?

If you run a furnace without a filter for one night, it won't affect your HVAC system detrimentally. However, the longer you run your heating system without an air filter, the more contaminants accumulate inside your heating unit inner mechanisms.

Sicilia Jesk

Reviewer

How often should you change your furnace filter in the winter?

Frequency of the Change
say that you should change your air filter at least every three months. During the winter, when you rely on your heating system more, you want to increase that frequency. During the winter, when the system is in constant use, change it out every month.

Pieternella Grossen

Supporter

Do you need to change furnace filter in summer?

Since all of the air that you breathe in your home flows through the furnace filter, it is extremely important that this filter be changed, at the very least, every three months if not monthly. So, yes, your furnace filter needs to be changed even in the summer.