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27.01.2025
Brooke Kirshne
Choosing the correct air filter size for your HVAC system is essential for its proper operation. If the filter does not fit correctly, it can cause your system to work harder, leading to higher energy costs and reduced efficiency. An incorrect size air filter can also negatively impact your indoor air quality, allowing dust, allergens, and harmful pollutants to collect, which can affect your health and comfort.
In this guide, we’ll walk you through how to measure your air filter accurately and explain the difference between nominal size and actual size. We will help you understand how to select the right MERV rating for your needs and highlight the benefits of custom air filters for specific HVAC systems. Choosing the correct size ensures that your air filtration system works effectively and helps maintain air quality in your home.
Additionally, we’ll cover the importance of air filter replacement and regular filter maintenance to keep your HVAC system running smoothly. A correctly sized filter extends the life of your system, improves its performance, and prevents dust and allergens from accumulating. By following these tips, you’ll be able to make the right choice to improve air quality, manage energy efficiency, and reduce unnecessary strain on your HVAC system.
Understanding Air Filter Types
Choosing the right air filter for your HVAC system is important to keep it running well and improve indoor air quality. There are different types of air filters, each designed for specific needs. Knowing the options available will help you pick the best one for your system.
1. Fiberglass Filters
Fiberglass filters, also known as flat-paneled filters, are made from spun glass fibers held together by a metal frame. They are an affordable option, making them a popular choice among many homeowners. However, these filters mostly capture larger particles like dust and pollen, which means they do not quite improve indoor air quality. While they may be budget-friendly, they are not the best choice for those looking for effective air filtration or better air quality. If you are seeking better filtration, you might want to consider other options.
2. Pleated Filters
Pleated filters are made from folded fabric, usually cotton or polyester, which increases the surface area of the filter. This design helps with air filtration, capturing more airborne particles like allergens, mildew, mold spores, and pet dander. The more pleats, the better the filter works to improve indoor air quality. While pleated filters can cost more than fiberglass options, they offer superior air quality and come in both reusable and disposable versions. They’re a great choice for homes where people suffer from allergies or have pets because they are more efficient at trapping harmful pollutants.
3. HEPA Filters
HEPA (High-Efficiency Particulate Air) filters are some of the most effective filters for removing airborne particles. They can trap up to 99.97 percent of contaminants including germs, viruses, mold, dust, and pollen. These filters are great for environments that require clean air quality such as hospitals or homes with vulnerable residents. While HEPA filters are more expensive than other air filters they are worth the investment, especially for people with respiratory issues or severe allergies. Their ability to provide superior air filtration makes them an excellent choice for improving indoor air quality.
4. Electrostatic Filters
Electrostatic filters use a mixture of paper fibers and cotton to create a static charge that attracts and captures particles as air passes through. Available in both flat and pleated styles these filters can be washable or disposable. Their static charge improves air filtration which makes them particularly effective at trapping fine particles like pet dander, dust, and allergens. This makes them a great choice for improving indoor air quality in homes with people who suffer from allergy problems. These filters also help maintain energy efficiency by reducing pressure on your HVAC system. With better air quality, you will be able to create a healthier environment while reducing the need for frequent air filter replacement.
5. UV Light Filters
UV light filters use ultraviolet light to kill viruses and bacteria in the air making them an important part of your home’s air purification system. However, they are not meant to capture dust or other particulate matter. For the best results, UV light filters are often paired with other filters, such as HEPA filters to provide complete air filtration and improve overall air quality. When used together these filters help manage indoor air quality effectively and create a healthier living environment.
6. Washable Filters
Washable filters are available in both flat and pleated styles and are made to be reused. While they may have a higher upfront cost they help you save money over time and they are more environmentally friendly compared to disposable options. To keep them working well regular cleaning is necessary. It is also important to make sure the filters are completely dry before reinstalling them to prevent mold growth. With proper maintenance washable filters can improve your air filtration, enhance indoor air quality, and reduce the frequency of air filter replacement.
7. Media Filters
Media filters are made of pleated material locked in a metal frame providing a large surface area to capture particles effectively. These filters are low-maintenance and can last up to two years. They are about seven times more efficient than standard filters making them an excellent option for homes that need better air filtration. Media filters are especially useful for people living in industrial areas or those with health issues as they offer a higher level of air purification. By using these filters you can improve indoor air quality while reducing workload on your HVAC system helping to maintain both energy efficiency and filter maintenance.
Find The Size Label On Your Filter
When selecting or replacing an air filter, it is important to check the measurements printed on the side of the filter. Most filters show two sizes. The larger number is the "nominal" size, which is a rounded measurement and serves as a general reference typically displayed in a larger font. The smaller number is the "actual" size which provides the exact dimensions of the filter and is usually written in a smaller font. Knowing the actual size of your air filter is important for confirming it fits your HVAC system properly. Verifying these measurements helps prevent poor-fitting filters which can reduce system efficiency, leading to higher energy costs and poor air quality. Even the smallest differences in air filter size can affect how well your system performs so always trust these numbers to choose the correct size. This guarantees better air filtration and improved indoor air quality and helps maintain the energy efficiency of your system.
Air Filter Measurements: Nominal Size Vs. Actual Size
It's important to know how to distinguish between nominal and actual sizes when buying new air filters for your HVAC system. Understanding these two measurements makes sure that the filter you select fits properly helping to enhance system efficiency and maintain the air quality inside your home. An incorrect filter size can cause issues with air filtration, reduce the energy efficiency of your HVAC system, and negatively impact indoor air quality. Always double-check the nominal and actual size to make sure you're getting the right filter for your needs.
- Nominal Size: The nominal size is the approximate measurement of the air filter rounded to the nearest inch. This size is usually shown on the filter's packaging making it easier to identify and select the right filter. For example, a filter labeled 18x20x4 refers to a nominal size of 18 inches by 20 inches by 4 inches. Keep in mind that this is just a general estimate and the actual size may slightly differ.
- Actual Size: The actual size refers to the actual dimensions of the air filter. You can use a tape or a ruler measure to determine the exact length, width, and thickness of the filter. For example, a filter labeled 18x20x4 may have an actual size of 17.5 by 19.5 by 3.75 inches. Knowing the actual size is vital for ensuring a proper fit in your HVAC system which helps maintain both energy efficiency and air filtration.
How To Measure Your Air Filter In Simple Steps
For best performance and efficiency make sure your HVAC system uses the correct size air filter. A proper fit improves air filtration, boosts energy efficiency, and maintains good indoor air quality. An incorrectly sized filter can strain your system, affecting both performance and air quality.
Step 1: Switch Off Your HVAC System: Before starting any work, always turn off your HVAC system. This prevents the air filter from being pulled into the system ensuring a clean installation without particles affecting your air quality.
Step 2: Locate The Existing Air Filter: The air filter is typically located in the furnace, air handler unit, or return air grille. Knowing the filter's location makes it easier to remove and replace, ensuring a proper fit for your HVAC system.
Step 3: Remove The Old Filter: Carefully remove the existing filter from its housing, noting the direction arrows for airflow. This helps to ensure the new filter is installed in the right direction, maintaining proper air filtration.
Step 4: Measure Both The Length And Width Of The Filter: Use a tape measure to accurately measure the length and width of the air filter in inches. These dimensions are important to finding a filter that fits your HVAC system correctly and is the most effective use of indoor air quality.
Step 5: Take The Thickness Measurement: Measure the depth or thickness of the air filter to make sure it matches the required size. This ensures the new filter fits properly, preventing poor air filtration and system inefficiencies.
Step 6: Cross-Check Your Measurements: Verify that the nominal size and actual size of the filter match the measurements you’ve taken. This step is essential to ensure the filter fits correctly and improves energy efficiency in your HVAC system.
Step 7: Choose The Correct Replacement Filter: Choose a replacement filter that matches the nominal and actual sizes of the existing filter. This guarantees proper air filtration and the best indoor air quality while reducing strain on your HVAC system.
Step 8: Fit The New Filter Into The Slot: Insert the new air filter into its housing, ensuring it fits snugly and aligns with any airflow direction indicators. Once installed correctly, your HVAC system will run efficiently, improving air quality and energy efficiency.
Common Air Filter Sizes For HVAC Systems
| Standard Sizes | Larger Sizes |
|---|---|
| 10x20x1 | 16x20x4 |
| 12x12x1 | 16x25x4 |
| 14x20x1 | 20x20x4 |
| 14x25x1 | 20x25x4 |
| 16x20x1 | 12x24x4 |
| 16x25x1 | 14x24x4 |
| 18x20x1 | 16x30x4 |
| 20x20x1 | 18x24x4 |
| 20x25x1 | 20x30x4 |
| 24x24x1 | 24x30x4 |
The Perfect Fit Is Key To A Long-Lasting HVAC System
Choosing the right air filter is essential to ensuring the longevity and best performance of your HVAC system. A correctly sized filter efficiently captures dust, debris, and other particles, allowing your system to function without strain. When your HVAC system is free from harmful buildup, it runs smoothly, reducing the risk of costly repairs and extending its lifespan.
A properly fitted air filter also promotes good airflow, minimizing energy consumption by preventing unnecessary strain on the system. By selecting a filter that aligns with your HVAC system’s requirements, you safeguard your investment and improve indoor air quality. This ensures your HVAC system operates efficiently, keeping your home’s air quality high and the system running for years.
Conclusion
Ensuring your air filter fits properly is important for the efficient operation of your HVAC system. This straightforward guide helps you measure your air filter accurately, ensuring you select the right size. Choosing the correct-sized filter is vital not only for maintaining excellent indoor air quality but also for extending the life of your HVAC system. By carefully measuring both the nominal and actual sizes, you can guarantee the best performance and protect your investment in the long run.
Looking for high-quality HVAC air filters? We’ve got you covered! At Custom Filters Direct, we offer premium filters that deliver trustworthy filtration solutions ensuring your HVAC system runs efficiently and effectively. Whether for your home or business, our filters are designed to optimize air quality and system performance. Reach out today to discover more about our products and how they can improve your HVAC system. Contact us at 877-958-5612 or email info@customfiltersdirect.com for assistance. We’re here to help!
