Which Furnace Filter Size is Best for a Wood-Burning Fireplace?

Are you a proud owner of a wood-burning fireplace and looking for the best furnace filter size? Look no further! Your search ends here on this informative blog post, dedicated to helping you find the perfect size for your wood-burning fireplace. Keeping your home warm and cozy is easier with the right furnace filter size.

But why is choosing the right furnace filter size so important? A wood-burning fireplace produces a lot of dust and ash, making it essential to have a filter that can capture these harmful elements. Having a filter that is too small or too large can result in poor air quality and even damage to your furnace. So, read on to discover the best furnace filter size for your wood-burning fireplace.

With a wide range of furnace filter sizes available, it can be tough to find the right one for your wood-burning fireplace. In this blog post, we’ll explore the different options available and help you choose the perfect filter size for your home. So, what are you waiting for? Let’s get started on the journey to cleaner air and a more efficient furnace.

Understanding Furnace Filter Sizes

Furnace filter sizes play a crucial role in maintaining the indoor air quality of your home. Filters with the incorrect sizes may not fit properly, fail to filter effectively, or even damage your furnace system. Understanding furnace filter sizes will help you to choose the right one for your home, ensuring maximum performance and comfort.

Furnace filters are categorised by their dimensions, which include length, width, and thickness. The size of your furnace filter depends on the type of furnace system you have installed in your home. You can find your existing filter size by checking the dimensions listed on the old filter or by measuring the filter housing.

Additionally, it's important to note that not all furnace filters are standardised. Some manufacturers produce custom-sized filters that may not be compatible with other furnace systems on the market. That's why it's essential to check and verify the filters' appropriate sizes before making the purchase.

The most common furnace filter sizes include 16x20x1, 20x25x1, 16x25x1, 14x25x1, 20x20x1, and 16x20x4, among others. Knowing your furnace filter's size will not only help you to choose the right replacement filter but also save you time and money.

Finally, the frequency of replacing your filter depends on the type of filter and your home's specific needs. High-efficiency filters may require more frequent replacements than standard filters, and if you have pets, allergies or suffer from asthma, you may need to replace your filters more frequently as well.

Understanding furnace filter sizes is crucial in maintaining the air quality in your home. It helps to ensure that the furnace filter you choose fits correctly and performs its intended function efficiently. So, know your furnace filter size, and change your filter regularly to protect your home's air quality and your family's health.

What to Consider When Choosing a Filter Size

Choosing the right filter size for your wood-burning fireplace can be a daunting task. With so many options available, it's important to keep a few key factors in mind.

The first thing to consider is the size of your furnace. Choosing a filter that's too big or too small can lead to decreased efficiency and potential damage to your system. Check your furnace manual or consult a professional to ensure you're selecting the right size.

The second factor to consider is the level of filtration you need. If you or anyone in your household suffers from allergies, a high-efficiency filter may be the best choice. These filters are designed to capture even the smallest particles, including pollen and pet dander. However, they can also restrict airflow and may require more frequent replacement.

Lastly, consider the cost of the filter. While high-efficiency filters may offer better filtration, they also tend to be more expensive. Be sure to balance your filtration needs with your budget to find the best option for you.

By keeping these factors in mind, you can choose the right filter size for your wood-burning fireplace and enjoy clean, efficient heating all winter long.

Common Furnace Filter Sizes for Wood-Burning Fireplaces

Choosing the right furnace filter size is essential for maintaining your wood-burning fireplace's efficiency and preventing harmful airborne particles from circulating in your home. Here are some of the most common furnace filter sizes for wood-burning fireplaces:


This is one of the most common furnace filter sizes for wood-burning fireplaces. It is suitable for most standard-sized fireplace systems and is readily available in most home improvement stores.


This filter size is another commonly used option for wood-burning fireplaces. It is ideal for smaller fireplaces, single-family homes, and apartments.


Similar to the 20x25x1, the 20x20x1 is an option for fireplaces that require slightly smaller filters. It is perfect for small-sized homes and apartments.

Whichever furnace filter size you choose, make sure to check the manufacturer's recommendations first. Remember, choosing the correct filter size is essential to keep your home safe and comfortable during the colder months.

Factors That Determine the Best Furnace Filter Size

Choosing the right furnace filter size for your wood-burning fireplace is essential to keep your indoor air clean and free from harmful particles. But what factors should be considered to determine the best furnace filter size?

1. Fireplace Size: The size of your wood-burning fireplace is the primary factor that determines the filter size you need. A larger fireplace will require a larger furnace filter, while a smaller one will need a smaller filter.

2. Efficiency: The higher the efficiency of the filter, the better it will perform to trap particles in the air. However, filters with high efficiency also tend to have lower airflow rates. This means that you will need a larger filter to compensate for the lower airflow if you choose a more efficient one.

3. Type of Filter: There are various types of filters available in the market, including fiberglass, pleated, washable, and electrostatic. Each filter has its own airflow rates and efficiency levels, which can impact your furnace filter size requirements.

4. Airflow Requirements: The airflow requirements of your wood-burning fireplace also play a crucial role in determining the best filter size. Higher airflow rates will require a larger filter to maintain the same level of efficiency.

5. Frequency of Filter Changes: Lastly, the frequency of filter changes can also affect the furnace filter size you need. If you change your filter frequently, you can opt for a smaller one that will perform just as well as a larger filter.

In conclusion, choosing the best furnace filter size for your wood-burning fireplace requires careful consideration of several factors, including fireplace size, filter efficiency, type of filter, airflow requirements, and frequency of filter changes. By taking these factors into account, you can ensure that you get the right filter for your needs and maintain clean indoor air quality.

Tips for Maintaining Your Furnace Filter and Ensuring Proper Functioning

Regular maintenance of your furnace filter is crucial for ensuring that your wood-burning fireplace operates efficiently and safely. Here are some tips to help you maintain your furnace filter:

1. Replace Your Filter Regularly

You should replace your furnace filter at least once every three months, even if it doesn't look dirty. A dirty filter will reduce the airflow through your system, making it work harder and longer than necessary. This will result in increased energy bills and a shorter lifespan for your furnace.

2. Check Your Filter Monthly

Make sure to check your furnace filter at least once a month to see if it needs to be replaced. If it looks dirty, replace it immediately. A clogged filter can cause your furnace to overheat and even shut down, which can be dangerous.

3. Use the Right Filter

Make sure you use the right filter for your furnace. Some filters may fit, but they may not be the right type or size. Improper filters can reduce airflow and cause your furnace to work harder, leading to increased energy bills and reduced efficiency.

4. Keep Your Ducts Clean

Dirty ducts can restrict airflow, making your furnace work harder and reducing its lifespan. Make sure to clean your ducts regularly to ensure they are free from dirt and debris.

5. Hire a Professional

If you are unsure about maintaining your furnace filter, or if you suspect a problem, it is best to hire a professional. A certified HVAC technician can inspect your system and provide any necessary repairs or maintenance to keep your furnace running safely and efficiently.

By following these simple tips, you can ensure that your furnace filter is properly maintained and functioning at its best. This will not only save you money on energy bills, but it will also help prolong the life of your furnace and ensure that your wood-burning fireplace is operating safely.


In conclusion, choosing the right furnace filter size for your wood-burning fireplace is crucial to ensure efficient and healthy heating. The size you choose will depend on your furnace's capacity and your home's heating needs. Make sure to check your furnace's manual, consult with a professional, and consider the level of filtration you require based on your local air quality. Invest in a high-quality, properly fitting filter to safeguard both your home and your health. With the right furnace filter size, you can enjoy the warmth and coziness of a wood-burning fireplace without sacrificing air quality.

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.