“Maximize Indoor Air Quality with Honeywell FC100A1037-5 Merv 11 Filters – Pack of 5”

Price: $189.00 - $124.00
(as of May 02, 2023 04:26:59 UTC – Details)

buy now

AC Filter 20x25x4: Everything You Need to Know

When it comes to keeping your air conditioning unit in top condition, few things are as important as the air filter. Not only does it help to improve the indoor air quality, but a clean air filter contributes to the unit’s overall efficiency and helps to lower energy bills. However, with so many air filters on the market, it can be confusing to know which one to choose, especially when it comes to the AC filter 20x25x4. In this article, we’ll explore everything you need to know about this size of air filter.

What is an AC Filter 20x25x4?

An AC filter 20x25x4 is an air filter that measures 20 inches in width, 25 inches in height, and 4 inches in thickness. These filters are typically made of pleated material, which increases the surface area of the filter medium and helps to trap more particles. The 20x25x4 size is common in residential HVAC units, and a clean filter of this size can help to remove pollen, dust, and other pollutants from the air.

Factors to Consider when choosing an AC Filter 20x25x4

Before buying an AC filter 20x25x4, it’s important to consider a few factors to ensure you choose the right filter for your needs.

1. MERV Rating: The Minimum Efficiency Reporting Value (MERV) is a rating system that indicates a filter’s ability to capture different sized particles. A higher MERV rating indicates a filter can trap smaller particles. However, a higher MERV rating can also restrict airflow and put more strain on the HVAC system. For residential HVAC systems, a filter with a MERV rating between 8 and 13 is typically recommended.

2. Filter Material: AC filters 20x25x4 come in various materials such as fiberglass, polyester, and pleated fabric. Pleated fabric filters are more effective at removing airborne pollutants, while fiberglass filters are more affordable.

3. Frequency of Replacement: The frequency at which you need to replace the AC filter 20x25x4 depends on several factors, such as the quality of air, usage patterns, and whether you have pets. Experts suggest replacing the filter every 3 months.

The Benefits of an AC Filter 20x25x4

There are several benefits to using an AC filter 20x25x4:

1. Improved Indoor Air Quality: The filter helps to trap airborne pollutants, which can cause allergies and respiratory problems.

2. Increased Efficiency: A clean filter ensures that the HVAC unit works efficiently, lowering energy bills, and prolonging the unit’s lifespan.

3. Easy Maintenance: Replacing the filter is a straightforward task that can be done in a matter of minutes, even by a novice.


Q1. Can I use a filter with a higher MERV rating than recommended?

While a higher MERV rating indicates a more efficient filter, using one with a rating too high for your HVAC system can restrict airflow, causing damage to the unit or even reducing its lifespan.

Q2. How often should I replace the AC filter 20x25x4?

For residential HVAC systems, experts recommend replacing the filter every three months.

Q3. Can I clean my AC filter 20x25x4 rather than replacing it?

Cleaning the filter is not recommended. A clean filter traps pollutants better than a dirty one. When you clean the filter, you could damage the fibers, which can reduce the filter’s efficacy.

Q4. Can I reuse my old filter?

Reusing an old filter is not recommended. The filter has passed its useful life and may not effectively trap pollutants.

Q5. Is it better to buy a washable filter?

Washable filters may initially appear to be a cost-saving alternative. However, they require regular cleaning, which can be time-consuming, and can stretch or damage the material. Over time, washable filters also become less effective in capturing pollutants.


When choosing an AC filter 20x25x4, it’s essential to consider the MERV rating, filter material, and frequency of replacement. The benefits of using this type of filter are numerous, including improved indoor air quality, increased efficiency, and easy maintenance. Remember to replace the filter every three months and avoid washing or reusing it. Keeping in mind the factors mentioned above, choosing a quality air filter will help to ensure a healthy indoor air environment and a well-functioning HVAC system.

You May Also Like