top of page
  • Writer's pictureStacie

All About Filters

As you walk through your local hardware, grocery, or retail store you will notice that the choices of filters are many. They range from inexpensive to costly, from standard 1 inch to pleated 2 inch, from low filtering to high filtering, from 30 day to 3 month. Which one to choose can be confusing. Do I need the inexpensive one to fit my budget or the expensive high filtering one that lasts 3 months? All are very good questions with no one universal answer. The truth of the matter is it depends on many factors and these factors determine which type of filter you should choose. I will walk you through the difference in filters, which type of filter better suites your needs, and good filter maintenance practices.

What Does A Filter Do?

The answer to this question may seem obvious. It filters particles out of the air, right? Well, yes it does, but what is the importance of filtering these particles from the air? First and obviously would be improved air quality for a healthier environment inside the home or office. Another just as important reason that you may not be aware of, like filtering these particles to keep the coil in the air handler clean. A dirty coil can reduce air flow which reduces the system’s ability to transfer heat and cold into your home. Also, it helps to keep the drain lines clear and prevent drain clogs. Particles that are not filtered out can collect on the coil and then wash down into the drain line as the moisture is removed from the air. Dirty filters usually lead to clogged drains. Lastly, it is to keep your system’s blower free of dirt and particles. Your home’s air handler has a blower that contains dozens of small cupped vanes. If the air that is passing through this blower is full of particles, those particles will collect on the blower. As these particles build up, they fill in these small cupped vanes, making them less cupped and flatter. This reduces the amount of air the blower is capable of moving. In turn this creates refrigeration pressure issues which reduces your system’s capacity and increases wear and tear on the entire system. Another issue is to keep as much dirt as possible out of the duct and equipment. As dirt builds up in your system it gives mold spores a place to collect and grow. Keeping the amount of dirt that passes through the system minimal helps reduce this environment for mold growth. So, as you can see there are many good reasons to keep the air that passes through your system clean.

Different Types of Filters

1" & 2" Standard Disposable 30 day filter

1” Standard Disposable 30 Day Filters:

Typically, the inexpensive 1” standard style filter is the most common. In the industry these filters are referred to as “rock stoppers”, meaning that they are going to stop the larger particles such as dust, larger pollen particles, and hair. Of course, there are varying types of these filters. The least filtering of these is the style that usually has a green filtering fiber and when stacked together they will nest inside of one another. Another style of this filter has a filtering screen that is the full 1 inch thickness of the filter and usually comes with either a blue or white filtering screen. These filters are good at protecting your equipment as long as you change them at least every 30 days. If you have high traffic in the area being filtered, you may need to change these filters every 2 weeks.

1” Pleated Disposable 3 Month Filters:

These filters are a step above the 1” standard in the fact that they filter even smaller particles such as fine pollen particles, lager bacteria or mold spores, and some even claim to filter virus particles. These filters do a very good job at filtering the air that passes through, but the length of time to leave them in place varies depending again on the traffic that is in the area being filtered. To leave these filters in place for a full 3 months would require that you have very low foot traffic in the area. No pets, no children, and no more than two people. If your foot traffic is high, then these filters may need to be replaced as often as every two weeks.

Various Sizes of Pleated Filters

2” Standard Disposable 30 Day Filters:

These filters are a little less common and you would need to make sure that your filter holding frame will accommodate a 2” filter before purchasing these. Typically, these filters are seen in commercial applications. They filter better than the 1” standard disposable filter, but not quite as well as the 1” pleated disposable filters. And as with the others filter life depends on foot traffic.

2” Pleated Disposable 3 Month Filters:

As with the 2” standard filter, be sure to verify that your filter holding frame will accommodate this filter. These filters are also more common in commercial applications but on occasion are found in residential applications. These filters are very good at filtering particles out of the air in the conditioned space and are about the best short term disposable filter you can purchase. Filter life rules for this filter are the same as the 1” pleated filter.

1” Electrostatic Washable Filters:

These filters are not quite as common but can be found in some stores and online. They have a multi layered metal filtering core with a either a rigid metal or plastic frame. The filter can be washed and reused again and again. It works by creating a positive electrostatic charge as the particles through the filter the positively charged particles and then drawn to the metal core and remain there until you wash the filter. These filters are higher priced than any of the disposable filters but if you break down the cost over the lifetime of the filter, the cost can be less than the 1” pleated filters. The electrostatic filter does not filter allergens and other small particles as well as the pleated filters and they do need to be cleaned quite often, typically every two weeks to 4 weeks, to keep them operating at peak performance.

Electrostatic Washable Filter

When is the Right Time to Change Your Filter?

As mentioned above the filter’s lifespan depends on foot traffic in that filtered area. The best way to tell if a filter needs to be changed is hold the dirty filter up and look through it towards a window. With the standard disposable filters, if you cannot make out clear images through the filter it needs to be replaced. Just seeing light through it is not enough. For pleated filters hold it up to a window the same way as a standard filter. If you can see light shine through it is okay. If you cannot it is time to change the filter. If your filter is being pulled out of the filter rack by the air flow or if it begins to make an unusual whistling sound it is time to replace the filter.

**If you are having trouble finding the location of your filters, finding your filter size, or with the replacement of your filters give All Seasons Heating and Cooling a call and we will be happy to assist you. For our ESA clients, usually we will be able to provide you filter sizes and locations over the phone.


Recent Posts

See All

System check VS Precision Tune-up

By now I’m sure you all have seen or heard advertisements for a low cost furnace or heat pump system check to get you ready for the heating season. Many of these ads promise lower energy bills and few


bottom of page