Newer systems often use pleated filters, also rectangular with a depth of about one inch. You should replace these about every 90 days, if you have no allergies, but AC pros typically recommend every 45 days for max efficiency. Be sure to replace them with the right size and type of air filter.

How often do HVAC filters need to be changed?

every 90 days





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.

Does HVAC air filter size matter?

Does Size Matter? You’ve guessed it! The answer is yes. It is essential to use the right size air filter for your HVAC unit to keep your system running smoothly and to reap all the benefits your air filter has to offer.

How do I know what size HVAC filter I need?

Follow these 3 easy steps:

  1. Follow these 3 easy steps:
  2. Step 1 – Measuring Length and Width (L x W). …
  3. Step 2 – Measure the thickness of your filter from front to back.
  4. Step 3 – Put Your Measurements Together (L x W x D).
  5. It’s as simple as that – You are now ready to buy the right filter for your AC or Furnace.

What size are most AC filters?





Most Common Furnace and AC Filter Sizes

  • 10 X 20 X 1”
  • 14 X 20 X 1”
  • 16 X 24 X 1”
  • 18 X 30 X 1”
  • 20 x 20 x 1.
  • 16 x 25 x 1.
  • 20 x 25 x 1.
  • 20 x 25 x 4.

How often should you change a 4 inch air filter?

every six months

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 often should AC filters be cleaned?

Clean or replace your air conditioning system’s filter or filters every month or two during the cooling season. Filters may need more frequent attention if the air conditioner is in constant use, is subjected to dusty conditions, or you have fur-bearing pets in the house.

What is the standard AC filter size?



Standard air filter sizes include:

10X20 14 X 20 20X20
12X12 14X24 24 X 24
12X20 14X25 20X24
12X24 14X30 20X25
12X30 15X20 20X30

Are 4 inch filters better than 1 inch?

The 4-inch thick air filter has a definite advantage over the 1” filter in terms of longevity, airflow and maximum filtering potential. Thus, if it fits your furnace, then a 4-inch air filter is better than a 1-inch air filter in regards to improving air quality.

Are thicker HVAC filters 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 heating, ventilating, and air conditioning (HVAC) system.

Why are air filters different sizes?



The die-cuts (filter frames) are manufactured in bulk and purchased as a raw material for making air filters and determine the exact size of the air filters. The exact size is always slightly smaller than the nominal size to allow the filter to properly fit in the slot or housing.

How do I know which air filter to buy?

Simply, you need the filter size that fits in your air return. You can typically find that size on the side of the air filter that you already have in use. This size will be the nominal size, which means it is rounded from its actual size. This is the size you click on at secondnature.com.

How many filters does an HVAC system have?

2 air filters

Typically, a house will have 2 air filters in their intake vents. In some cases, there can be more or fewer depending on the square footage of the home or apartment and the number of floors that need to be supported by the central air system.

Why does my AC have 2 filters?



A lot of central air units have at least two filters, though you can find systems that have only one. The reason why there are a couple of filters is because not only the air that is traveling into the air handler needs to be filtered, but also the air passing through the return vents.

Do HVAC systems have 2 filters?

Yes, your central air conditioner has a filter. In fact, most central AC units have two or more filters. These filters clean the air and ensure good air quality as your unit circulates between inside and outside air. Central air conditioner filters often are made of fiberglass or pleated materials.

What are the types of filters in HVAC system?

4 Types of HVAC Filters

  • HEPA Filter. HEPA filters offer the highest level of protection against a variety of airborne particles. …
  • Reusable Air Filters. Reusable are filters are washable filters that can simply be cleaned up and used again. …
  • Flat-Paneled Fiberglass Filters. …
  • Pleated Media Filter.

What are 3 different types of air filters?



Here are the three main types of air filters:

  • Fiberglass Filters. This type of filter consists of layered fiberglass fibers laid over each other. …
  • Pleated Air Filters. A pleated or polyester filter is usually a significant step up from a fiberglass filter. …
  • HEPA Filters.

Do HVAC filters help with Covid?

Portable air cleaners and HVAC filters can reduce indoor air pollutants, including viruses, that are airborne. By themselves, portable air cleaners and HVAC filters are not enough to protect people from the virus that causes COVID-19.

Are pleated air filters better?

While fiberglass air filters will do the job in the most basic way, in most cases, pleated air filters are much better. They can filter out smaller particles – important for people with airborne sensitivities. They are less likely to clog in a short amount of time, and they can last up to 90 days.

What filters do HVAC techs recommend?

HEPA Filter — HVAC replacement companies typically recommend HEPA filters because they can provide the highest protection level when it comes to airborne particles. This filter is capable of capturing small microns, and has a MERV rating between 17 and 20, meaning it can trap tobacco smoke and bacteria.

Are expensive AC filters worth it?

Yes, in general, the more expensive air filters are more effective, but a single person with no pets and allergies might not need as much filtration as a family of five with three pets and a child with asthma. Also consider how long your air filter will last.