Discover the Right Furnace Filter Size for Your Home Heating Needs

Are you tired of feeling chilly in your own home during the winter months? It could be because your furnace filter is the wrong size! Having the correct size filter can not only provide better heating but also improve air quality. In this article, we’ll help you discover the right furnace filter size for your home’s heating needs.

A furnace filter is an essential component of any heating system as it keeps the unit clean and free from dust and debris. Choosing the right size filter ensures that the air flowing through the furnace is properly filtered, preventing harmful particles from circulating in your home. Without the correct size filter, your furnace may struggle to push air through the system, resulting in uneven heating or no heat at all.

Don't risk being left in the cold this winter - learn how to choose the right furnace filter size for your home. We’ll cover everything from measuring your current filter to selecting the right MERV rating for your needs. So, if you're ready to improve your home’s air quality and enjoy improved heating this winter, keep reading!

How to Measure Your Current Furnace Filter

If you are wondering what the right furnace filter size for your home might be, the first step is to measure your current furnace filter. Here's how to do it:

1. Locate your current furnace filter.

This could be in your furnace or in the return air vent. It's important to know where your filter is so that you can access it easily.

2. Turn off the power to your furnace.

Safety first! Make sure that you turn off the power to your furnace before you start measuring your filter.

3. Remove the filter.

Carefully remove your existing filter from its housing. This can usually be done by lifting up on the filter or sliding it out of the housing.

4. Measure the length, width, and depth of your filter.

Using a measuring tape, measure the length and width of your filter. Be sure to measure the filter at its widest and longest points.

For the depth, measure the thickness of the filter. This measurement is important to ensure that your new filter will fit properly in your furnace.

5. Write down the dimensions.

Once you have measured the length, width, and depth of your filter, write down the dimensions so that you can refer back to them when you are shopping for a new filter.

By following these simple steps, you can easily measure your current furnace filter and ensure that you are purchasing the right size filter for your home heating needs.

Understanding MERV Ratings

MERV stands for Minimum Efficiency Reporting Value, and it refers to the effectiveness of a furnace filter in removing particles from the air. The MERV rating scale ranges from 1 to 20, with a higher rating indicating a more efficient filter. Filters with a MERV rating of 1 to 4 are basic filters that are only capable of removing larger particles such as dust and pollen. Filters rated 5 to 8 can catch smaller particles such as mold spores and pet dander, while filters rated 9 to 12 are considered high-efficiency filters that can capture even smaller particles such as bacteria and smoke. Filters with a MERV rating of 13 to 16 are typically used in hospitals and other medical facilities, as they can even capture viruses and exhaust fumes. However, it's important to note that higher MERV ratings may also reduce airflow and cause strain on your furnace, so it's crucial to consult with a professional before selecting a filter with a high MERV rating. In general, it's recommended to use a filter with a MERV rating between 7 and 12 for most residential heating systems. This will strike a balance between filtering out harmful particles and allowing proper airflow through your HVAC system. So, when selecting a furnace filter, be sure to consider your home's specific heating needs and consult with a professional to ensure you choose the right filter with the appropriate MERV rating.

Factors to Consider When Choosing a Furnace Filter

When it comes to choosing the right furnace filter for your home, there are a few factors to consider in order to ensure that you get the best performance and air quality.

Size: The first factor to consider when choosing a furnace filter is the size. Make sure to measure the dimensions of your filter slot to ensure that you purchase a filter that fits properly. A filter that is too small or too large can reduce the efficiency of your furnace and potentially cause damage.

MERV rating: The MERV (Minimum Efficiency Reporting Value) rating is a scale that measures the effectiveness of furnace filters. The higher the rating, the more particles and pollutants the filter will capture. However, filters with higher MERV ratings may also restrict airflow and put strain on your furnace. Consider a filter with a MERV rating of 7-12 for optimal performance without sacrificing airflow.

Type of filter: There are various types of furnace filters available, including fiberglass, pleated, and washable filters. Fiberglass filters are the least expensive, but also the least effective at capturing pollutants. Pleated filters provide higher filtration and airflow than fiberglass, while washable filters offer the convenience of being reusable. Consider your air quality needs and budget when choosing a filter type.

Health concerns: If you or anyone in your household suffers from allergies or other respiratory problems, consider a filter specifically designed to capture allergens and pollutants such as pollen, dust mites, and pet dander.

Frequency of replacement: Finally, consider how often you will need to replace your furnace filter. Most filters need to be replaced every one to three months, depending on usage and air quality. Choose a filter that is easy to replace and fits within your maintenance schedule.

By considering these factors, you can choose the right furnace filter for your home heating needs and ensure that your furnace operates efficiently and effectively.

Common Furnace Filter Sizes for Popular HVAC Brands

When it comes to choosing the right furnace filter size, it's essential to know the dimensions of your unit. However, if you're unsure, it's good to know the common sizes used for popular HVAC brands. Here are some of the most common furnace filter sizes for popular HVAC brands:

Carrier: 16x25x1, 20x25x5, 16x25x5, 20x20x1, 16x20x1

Lennox: 20x25x1, 16x25x1, 20x20x1, 16x20x1, 20x25x5

Trane: 14x25x1, 16x25x1, 20x25x1, 24x25x1, 20x25x5

York: 20x25x1, 16x25x1, 20x20x1, 16x20x1, 20x25x5

Rheem: 16x25x1, 20x25x1, 14x20x1, 16x20x1, 20x25x5

Remember, these are just some of the most common sizes, and it's always best to double-check the dimensions with your unit or consult with a professional before making any purchases.

Choosing the right furnace filter size is critical for the effective functioning of your HVAC system. It helps to keep your home's indoor air quality healthy and comfortable by trapping dust, pet dander, and other allergens. Don't compromise on the air quality in your home; get the right furnace filter size for your HVAC system today!

The Importance of Regular Furnace Filter Replacement

Regular furnace filter replacement is an essential task that cannot be overlooked. The air filters in your furnace serve as the primary defense against pollutants, dust, and other particles that can negatively impact your indoor air quality. Over time, these filters become clogged and less effective, resulting in poor airflow and increased energy bills.

By replacing your furnace filter regularly, you can improve your indoor air quality and the efficiency of your heating system. It's recommended to change your furnace filter every one to three months, depending on usage and the type of filter in use.

Not replacing your filter can lead to a host of problems, including reduced HVAC system lifespan, increased energy bills, and poor indoor air quality. A clogged filter causes your furnace to work harder, leading to more wear and tear on the system, and potentially costly repairs or replacement in the future.

In addition to better indoor air quality and energy efficiency, replacing your furnace filter has several other benefits. It can reduce the likelihood of system breakdowns, prolong the lifespan of your furnace, and help you avoid costly repair bills. Plus, clean filters can improve the efficiency of your furnace operation, resulting in a more comfortable home with a stable temperature.

Overall, regular furnace filter replacement is a cost-effective way to maintain your heating system and improve your indoor air quality. Don't wait until your furnace is experiencing performance issues to change your filter. Keep track of when you need to replace it and always have a spare on hand. A little bit of maintenance can go a long way in keeping your furnace running efficiently and your home comfortable all winter long.


Choosing the right furnace filter size for your home heating needs is critical for ensuring efficient and effective heating. By considering factors such as the size of your furnace, the frequency of filter changes, and the types of pollutants present in your home, you can make an informed decision on the best filter size for your home. Remember, regularly changing your furnace filter is essential for maintaining the longevity and performance of your heating system, and ultimately, for keeping your home comfortable throughout the winter months.

So, take the time to review your furnace filter size, and ensure your home is protected from airborne particles and allergens all winter long. With a little bit of knowledge and know-how, you can enjoy warm, clean, and filtered air for many seasons to come.

Frequently Asked Question

It's important to know the size and type of furnace filter you need before replacing it. This is because different furnaces require different sizes of filters. Your brand of furnace may need an electrostatic or media filter of a particular size - so make sure to check your old filter for these details.

Replacing your filter regularly can save you money in the long run. It helps your HVAC system become more efficient, and also keeps the air quality high. So, what are the most common furnace filter sizes?

The most popular furnace filters come in the following dimensions: 10x20, 14x20, 16x24, 18x30, 12x12, 14x24, 16x25, 20x20, 12x20, 14x25, 18x18, 20x24, 12x24, 14x30, 18x20, 20x25, 12x30, 15x20, 18x24, 20x30, 12x36, 16x20, 18x25, 24x24 and 25x25. You can use your existing filter as a reference guide to find the perfect size for your furnace. The filter dimensions should be printed on its frame as length x width x height.

In conclusion, it's important to know your furnace filter size before you replace it. Doing so will improve your HVAC system's efficiency and save you money in the long run. Plus, a clean filter is key to keeping your air quality high.

When it comes to furnace filters, exact size matters. If you get a filter that is too small or too big, air will flow around it instead of through it, meaning not all of the air will be filtered. That's why it's essential to use the right size filter for your HVAC unit.

Here's what you need to know: the size of the air filter is typically listed in the big, bold font on the packaging, which is known as the nominal size. This is a rounded-up whole-number version of the actual size, which is written in the fine print on the filter's frame. That's usually 0.25'-0.5' smaller than the nominal size, and the actual measurements of the filter may vary slightly depending on the brand.

In some cases, less common sizes come true to size, meaning the nominal size is the same as the actual size. When that's the case, it's usually noted with “actual size” in parentheses on the filter's frame.

So, the verdict is in: the answer to the question 'Do furnace filters have to be exact size?' is a resounding yes! Be sure to get the right size air filter for your system to ensure it runs smoothly and that you reap all the benefits your filter has to offer.

Are you looking for the best furnace filter? Look no further! Our team of experts at This Old House Reviews have researched the top five furnace filters on Amazon to help you find the perfect one for your HVAC system. Plus, these products are available at local home centers or online retailers like Amazon.

A great furnace filter can make all the difference. It will keep your HVAC system running smoothly, potentially leading to lower electricity bills and better air quality. That's why we've taken the time to compile a list of the best furnace filters for you.

At the top of our list is the Filtrete furnace air filter. It promises to last up to three months and outperform filters made with fiberglass. Plus, it can capture 64% of airborne particles like pet dander and pollen. This filter also comes with instructions for easy installation on HVAC systems that require filters 20 by 25 by 1 inches in size.

Customers love this furnace filter. They find it easy to install, sturdy, and a great value. However, some customers have faced difficulties with Filtrete’s app.

When choosing a furnace filter, make sure to take into account its size, filtration level, and material. That way, you can get the best filter for your specific needs.

Changing or replacing your furnace filter is one of the best ways to maintain a healthy, efficient HVAC system. But you need to make sure that you're using the right filter for your system. Here's a step-by-step guide to help you pick the perfect one!

First, measure the dimensions of your existing filter. This will tell you the length, width, and depth you need. The easiest way to do this is to look at the existing filter and buy the same size.

Next, you need to choose the right MERV rating. The MERV scale ranges from 1-20 and measures the filter's effectiveness at catching particles in the air. The higher the value, the more effective the filter is at trapping particles, but it also means less airflow.

Now it's time to decide on the type of filter. There are many options available, so take some time to research the best type for your system.

Once you have everything you need, it's time to install the filter in your furnace/air handler slot. Remove the old filter to make room for the new one.

Finally, make sure to replace your filter regularly. If it clogs up with dust and particulate, it can reduce airflow and become ineffective.

Furnace air filters are essential for your heating system. You should replace your filter at least once every three months. So, how do you select the best furnace filter for your needs? Let us help you out!

Generally, furnace filters are made up of a cardboard frame, fiberglass filter, and metal mesh. These materials work together to strengthen the filter and protect your HVAC components from dust and debris. Plus, they also help improve the air quality in your home. Without a filter, your HVAC system could become dirty and its performance would suffer.

As air passes through the furnace filter, it traps and catches any contaminants. If you don't replace or clean your filter regularly, it can obstruct airflow and cause damage to your HVAC system. In most cases, you should change your furnace filters every three months. However, you may want to replace them more or less often depending on the situation.