Why Maintaining the Correct Furnace Filter Size has Surprising Health Benefits

The importance of maintaining the correct furnace filter size should not be underestimated. In addition to prolonging the life of your furnace and improving its performance, having the right filter size can also have surprising health benefits for you and your family.

According to experts, a good furnace filter can help keep your indoor air quality high by trapping harmful particles such as dust, bacteria, and allergens. Not only can poor air quality trigger respiratory problems and allergies, but it can also affect your overall health and well-being.

If you're not sure about your furnace filter size or haven't changed it in a while, it's never too late to start. Not only will it help you enjoy a more comfortable and healthier living environment, but it will also save you money in the long run by preventing costly repairs down the road.

How the Correct Furnace Filter Size Improves Indoor Air Quality

When it comes to maintaining a healthy indoor environment, many homeowners overlook the importance of their HVAC system's furnace filter size. However, using the correct size filter can have surprising health benefits, particularly when it comes to improving the quality of the air you breathe.

The furnace filter is responsible for removing pollutants, dirt, and debris from the air as it circulates through your HVAC system. When the filter is the correct size, it can capture a larger volume of these harmful particles. This reduces the amount of debris that is released back into the air and subsequently breathed in by you and your family.

Respiratory health can be significantly impacted by poor indoor air quality, particularly for those who suffer from asthma, allergies, or other respiratory conditions. Using the right size furnace filter can help to reduce airborne irritants that can trigger respiratory issues, and also help to control the spread of viruses and bacteria throughout your home.

Having the correct furnace filter size can also help to prolong the lifespan of your HVAC system. If the filter is too small, it may become clogged more frequently, meaning you need to replace it more frequently. This places additional strain on your system and can lead to more frequent breakdowns, which can be costly to repair.

Ultimately, investing in the correct furnace filter size is a simple but effective way to improve indoor air quality, protect your respiratory health and extend the life of your HVAC system. Speak to your HVAC technician about the right size filter for your system today.

The Health Risks of Poor Indoor Air Quality

Poor indoor air quality can have a significant impact on your health. The air inside your home can contain a range of pollutants, including dust, mold, pet dander, and volatile organic compounds (VOCs). Exposure to these pollutants can have both immediate and long-term health effects.

Short-term effects of poor indoor air quality include headaches, fatigue, dizziness, and irritation of the eyes, nose, and throat. If you are exposed to high levels of pollutants, you may experience more severe symptoms such as nausea, asthma attacks, and respiratory infections.

Long-term exposure to poor indoor air quality can lead to more serious health problems. According to the Environmental Protection Agency (EPA), exposure to indoor air pollutants may increase your risk of developing respiratory diseases, heart disease, and cancer.

Children and elderly individuals are particularly vulnerable to the health effects of poor indoor air quality. Exposure to pollutants can exacerbate asthma and other respiratory conditions in children, and it can increase the risk of infection in elderly individuals.

Fortunately, there are steps you can take to improve the air quality in your home. One of the most important things you can do is to regularly replace your furnace filter. This can help remove pollutants from the air, keeping you and your family healthy.

In addition, you can improve indoor air quality by cleaning your home regularly, ventilating your living spaces, and avoiding products that emit VOCs. By taking these steps, you can create a healthier home environment and reduce the risk of health problems associated with poor indoor air quality.

Choosing the Right Furnace Filter Size

When it comes to choosing the right furnace filter size, the first thing to do is consult with your HVAC technician. They can advise on the best filter size for your specific furnace model and the air quality needs of your home.

Another important factor to consider when choosing a furnace filter size is the MERV rating. MERV stands for Minimum Efficiency Reporting Value and rates the effectiveness of a filter at capturing airborne particles. The higher the MERV rating, the more efficient the filter is at capturing particles, but this also means it can create more airflow resistance and therefore need to be changed more frequently.

Ultimately, choosing the right furnace filter size and MERV rating can significantly impact the air quality of your home and overall health of your family. Maintaining a clean air filter can reduce the amount of pollutants in the air, helping to alleviate allergies and asthma symptoms, as well as improve overall respiratory health.

Don't underestimate the importance of a properly sized furnace filter in your home. Make sure to consult with an HVAC technician and choose the right filter size and MERV rating to ensure you and your family can breathe easy.

How Often to Change Your Furnace Filter

The frequency with which you should change your furnace filter largely depends on several factors, including the type of furnace filter you have, the number of people and pets in your house, and the level of air pollution in your area. Generally speaking, if you have a basic fiberglass furnace filter, it's recommended that you change it every 30 days.

If you have a higher-end furnace filter, such as a pleated filter or a HEPA filter, you can typically go longer without changing it. Pleated filters can usually last three to six months, while HEPA filters can last up to a year.

However, it's important to note that these timelines are just general guidelines. If you have a large family and/or pets, you may need to change your furnace filter more frequently. Similarly, if you live in an area with high levels of air pollution, you may need to change it more often as well.

One easy way to tell if it's time to change your furnace filter is to simply check it visually. Hold the filter up to a light source and see if any light shines through. If not, it's likely clogged and in need of a replacement.

Ultimately, the key is to monitor your furnace filter regularly and change it as needed. Doing so can help improve the air quality in your home, extend the lifespan of your furnace, and even lower your energy bills.

Additional Ways to Improve Indoor Air Quality

Aside from maintaining the correct furnace filter size, there are other ways to improve the air quality inside your home. Here are some suggestions:

1. Let in fresh air. Opening windows and doors, especially in areas with good ventilation, can help improve indoor air quality significantly. If the weather permits, you can also spend some time outdoor to inhale some fresh air.

2. Use air purifiers. Air purifiers have become a popular choice for households, as they help eliminate airborne pollutants and allergens. These devices work by pulling in indoor air, filtering it, and then circulating the clean air back into the room.

3. Keep humidity levels in check. Maintaining proper levels of humidity inside your home can lower the chances of mold growth, dust mites, and other allergens. According to the Environmental Protection Agency (EPA), the ideal humidity range is between 30 and 50 percent.

4. Clean regularly. Keeping your home clean and tidy is also essential in improving indoor air quality. Regularly dust and vacuum to get rid of accumulated dirt and debris that can trigger allergies and other respiratory issues.

5. Consider plants. Certain plants are known to help purify the air, including snake plants, spider plants, and peace lilies. Adding some greenery to your home can both add aesthetic appeal and improve air quality at the same time.

By following these additional tips, you can make sure that you are breathing healthy air inside your home.


As you can see, having the correct furnace filter size is crucial for maintaining a healthy and comfortable living environment. Not only does it improve air quality and alleviate allergy symptoms, but it can also help prolong the lifespan of your HVAC system and reduce energy costs. By regularly replacing your filter and ensuring that it is the correct size, you can breathe easier and enjoy a more pleasant home environment. So be sure to check your filter size and make any necessary updates – your health and well-being depend on it!

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.