Your Guide to HVAC Filters

Indoor air quality can be improved significantly by replacing HVAC filters. Do you know what type of filter your HVAC unit has and what its rating is? Read to find out!

Understanding Different Types of HVAC Filters

Usually, filters come in standard sizes that match most residential and commercial HVAC units.

Before you order any new replacement filters, double check the size you need. Usually, you can find the dimensions labeled on the box or manual from the manufacturer. If you need to, get a ruler out and check the old fashioned way! Otherwise, give us a quick call and let us determine what you need.

There are many different kinds of air filters. Depending on the MERV rating, they can range anywhere from $2 to over $100.

You’ll need a custom sized filter if you have an unusually large or small HVAC unit. Most manufacturers only make standard sizes, though some will create custom fitted ones at higher prices.

Essentially, every building has a unique layout, meaning you can expect all kinds of oddly shaped filters across the market.

How Do HVAC Filters Work?

Air filters are sheets of foam and special perforated paper that works by trapping microscopic dust particles. Normally, you slide it in under a slot below the furnace unit inside what’s known as the return grille. They serve to keep your air conditioning system clean by preventing particles from polluting the indoors atmosphere.

However, most filters just block the dust and bacteria. They don’t destroy them. Over time, the screens will become clogged and become hazards themselves by building up an overload of particles.

This clog of dirt can lower the effectiveness of your overall system and increase your heating and cooling bill each month. Eventually, the dust will begin to collect on the coils deep within the HVAC system. It’s much more expensive to clean or replace the coils instead of just changing the filter.

Depending on the size of your building, how many people reside in it, and the filter type, you must change your filter every 1-3 months. Use good judgment and check for clear signs of buildup on the filter.

What are the Different Types of HVAC Filters?

There are several types of air filters on the market. Which one you choose for your home is largely dependent on you and your families individual needs. Those who suffer from severe allergies will want to spend a little extra on higher-quality filters, for example.

The amount of purification you want and the quality of air in your home all depends on the type of HVAC filter that you have. Let’s take a look at the various filter types out there.

There are four main types of HVAC Air Filters:

1 – Fiberglass

Fiberglass is a term used to describe threaded man-made glass material. Used in filters, it’s the cheapest and has the shortest lifespan compared to others. They are often called “disposable” filters because experts recommend you trash them after a month.

They are most effective at blocking larger particles, like bugs and dust mites. However, they aren’t very durable. Even with a reinforced metal frame, they won’t last longer than 30 days. Most HVAC filters that you see are made out of fiberglass. Individual strands of fiberglass are spun together to catch particulates that are brought in with the outside air.

Only large particles will be filtered by this type of filter, and dust is an excellent example of this. They are not high tech and will not help to keep your home free of smaller airborne matter. These filters are inexpensive as they usually cost anywhere from $2-$10 each. They can be thrown away without having to think twice about it. For this reason, they will likely continue to be the most common air filter used.

2 – Pleated or Polyester

These are similar to fiberglass filters. However, they have an added wired back for increased durability and ability to capture even smaller particles. Typically, they last up to 90 days. Pleated HVAC air filters cost more money than fiberglass HVAC filters, but many people wouldn’t consider them to be expensive.

So, while they might cost twice as much as their fiberglass counterparts, you’ll save more yearly using them. For an additional level of filtration, some people opt to use pleated air filters. These types of filters are often made out of polyester or similar material. They can eliminate additional particles such as pet dander, dust mites, and other medium-sized particles.

You can remove around 45% of particles from your home’s air with these systems. You have the choice of buying reusable or disposable pleated HVAC filters. The reusable ones can just be washed and dried, then put back into the system. Just like with fiberglass HVAC filters, the disposable pleated filters can be thrown out in the trash.

3 – Electrostatic Washable

These rely on static electricity to collect the dust, rather than filtered cloth or foam. While a relatively expensive option (around $30-100), it’s considered permanent, since all you need to do is wash it once a month, rather than replace the whole thing.

Electrostatic air filters work slightly differently than a traditional air filter. They are electrically charged with static and use the current to attract particles to the screen. They are then cleaned and reused. Cotton and paper are used to make up this filter. While these filters are not as powerful as HEPA filters, they are more commonly used for homes. HEPA filters and electrostatic filters are very similar in price. There are also disposable electrostatic filters

4 – HEPA

HEPA stands for high-efficiency particulate air, and these filters are capable of removing the most particulates from the air. High-Efficiency Particulate Arrestance filters (better known as simply HEPA) are the most efficient commercially available air filters on the market. With the ability to block and eliminate 99.97% of particles up to 0.3 microns in size, they will guarantee you the cleanest indoor air possible.

These are commonly used in powerful air purifiers for offices, medical labs, and in disaster recovery. Most quality HEPA units are over $100. They will leave your home free of a variety of contaminants. That includes smoke such as tobacco smoke and tree pollen. Air is forced through the filter that is made up of aluminum and fibers, and the different contaminants are removed during this process.

These are the most expensive of air filters out there, and they are often used for places such as hospitals or sterile rooms. HEPA filters can also be cleaned and reused.

What are Standard HVAC Filter Sizes?

While they might vary by the manufacturer, most filters in the industry come in set dimensions measured by inches, including:

  • 10 x 20
  • 12 x 12
  • 12 x 20
  • 12 x 24
  • 12 x 30
  • 12 x 36
  • 14 x 20
  • 14 x 24
  • 14 x 25
  • 14 x 30
  • 15 x 20
  • 16 x 20
  • 16 x 25
  • 18 x 18
  • 18 x 20
  • 18 x 25
  • 18 x 30
  • 20 x 20
  • 20 x 24
  • 20 x 25
  • 20 x 30
  • 24 x 24
  • 25 x 25

Where Do You Find Custom Filters?

If none of the above sizes match perfectly, you’ll want to order a custom-made filter to fit your system.

If you attempt to use a filter in the slot that is too small, air will just flow around it and render it useless. On the other hand, if you try to jam in a filter too large, the edges will become crushed in the tight space, and it won’t last very long.

There are plenty of companies that sell air filters of different sizes and materials, both offline and online. There are even companies out there that can design, engineer, and manufacture custom air filters according to your specifications.

You might want to explore companies such as Precision Filtration Products, Filtertech, or Koch Filter Corporation.

However, you should know that custom sized filters tend to cost more and may take 5-10 days to manufacture. HVAC filters are the cornerstone of your air handling system, whether it is for your home or business. You can get the level of clean air that you want. That means you can get an allergy free home or remove the smell of tobacco smoke from your home.

Call us first before you commit to any investment in a custom air filter. We can give you the exact measurements you’ll need and recommend the right brand.

Sig Cox Augusta Air Conditioning is here to serve you for all your heating and air quality needs. From simple fixes to new installations, we cover it all! We’re open 24/7 to handle any residential or commercial job.

Call us today for a free quote on your needs: (706) 722-5304

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