Don't Make These Common Mistakes When Using a Merv 11 Filter

Stop! Before you install that Merv 11 filter into your HVAC system, read this blog post. We're about to share some crucial information on common mistakes that many homeowners make when using these filters.

Don't let the Merv 11 filter's high efficiency rating lull you into a false sense of security. These filters, while effective, require some extra care and attention to achieve their maximum potential. We'll tell you what to avoid to ensure you get the most out of your filter, keeping your indoor air quality healthy and fresh.

Ready to learn? Let's get started with the top errors to avoid when using a Merv 11 filter in your home.

Choose the Right Size Filter for Your Needs

One of the most common mistakes people make when using Merv 11 filters is not choosing the right size. Using a filter that is not the correct size can reduce its effectiveness and cause air leaks around the edges, reducing the quality of air in your home.

It is essential to ensure that you choose the correct size of filter for your HVAC system. The size of the filter is determined by the dimensions of the filter holder, and you can find this information in your HVAC system manual.

If you are unsure of the correct filter size, it's best to consult an HVAC technician who can help you select the filter that will work best for your specific needs. Remember, using the wrong size filter can cause damage to your HVAC system, reduce indoor air quality, and negatively impact your health.

So next time you are purchasing a Merv 11 filter, make sure to choose the right size for your HVAC system to ensure the best possible air quality and performance.

Not Changing Your Filter Often Enough

One of the most common mistakes homeowners make when using a MERV 11 filter is not changing it often enough. While these filters are designed to trap smaller particles and can last longer than lower-rated filters, they still need to be changed regularly to maintain their effectiveness.

If you don't change your filter often enough, it can become clogged with dust, dirt, and other particles, reducing your indoor air quality and causing your HVAC system to work harder than necessary. This can lead to higher energy bills and potentially expensive repairs down the line.

So, how often should you change your MERV 11 filter? It depends on several factors, such as the size of your home, the number of people living in it, and the presence of pets or smokers. As a general rule of thumb, it's recommended that you change your filter every three months.

However, if you have pets or allergies, you may need to change it more frequently, perhaps every one or two months. Also, if you notice that your filter looks dirty or clogged, change it immediately. Don't wait until it's completely worn out to replace it.

By changing your MERV 11 filter regularly, you'll keep your indoor air clean and healthy while also prolonging the life of your HVAC system. So, don't make the mistake of neglecting your filter. Set a reminder to check and replace it every few months, and enjoy fresh, clean air in your home year-round.

Improper Installation of Merv 11 Filters Can Reduce Their Effectiveness

Installing a Merv 11 filter in your HVAC system can help improve indoor air quality by capturing small particles, such as pet dander, pollen, and dust. However, if the filter is not installed correctly, it may not work as efficiently as it should. Here are some common mistakes to avoid when installing your Merv 11 filter:

Installing the Filter Backwards

One of the most common mistakes when installing a filter is placing it backwards. Most filters come with an arrow indicating the direction of air flow, and it is important to follow this guide. If installed backwards, the filter will not capture the contaminants effectively and may even restrict air flow, reducing efficiency and damaging your HVAC system.

Not Sealing the Filter Properly

When installing a filter, it is important to ensure that it is sealed properly so that air does not bypass the filter. This can happen if the filter does not fit snugly or if the framing material is not installed correctly. Air bypassing the filter reduces its effectiveness and can contribute to poor indoor air quality.

Not Replacing Filters When They Are Dirty

A dirty Merv 11 filter is less effective than a clean one. It is important to check and replace filters regularly to maintain peak performance. Most filters need to be replaced every 3 to 6 months, depending on usage and environment. Neglecting to replace your filter on time can lead to a buildup of contaminants in your system, reducing efficiency and increasing maintenance costs.

By avoiding these common mistakes, you can ensure that your Merv 11 filter is installed correctly and working efficiently to improve your indoor air quality.

Neglecting to Address Other Indoor Air Quality Factors

While using a MERV 11 filter is an effective way to improve indoor air quality, it is not the only factor you should consider. Neglecting other important indoor air quality factors can lead to health problems and a less comfortable living environment. Here are a few factors to keep in mind:

1. Humidity: Humidity levels that are too high or too low can cause a variety of problems, including mold growth, respiratory issues, and discomfort. Consider using a dehumidifier or humidifier to maintain a healthy humidity level in your home.

2. Ventilation: Proper ventilation is crucial for maintaining indoor air quality. Make sure your home's ventilation system is functioning properly and consider opening windows or using exhaust fans to improve airflow.

3. Chemicals: Many household products contain volatile organic compounds (VOCs) that can negatively impact indoor air quality. Try to choose products with lower VOC levels and avoid using harsh chemicals whenever possible.

4. Pets and Smoking: Pets and smoking can both contribute to poor indoor air quality. Consider limiting smoking to outside and regularly grooming your pets to reduce dander and hair build-up.

5. Outdoor Air Quality: Outdoor air quality can greatly impact indoor air quality. Consider checking the Air Quality Index (AQI) for your area and using air filters or staying indoors during times when the AQI is particularly poor.

By addressing these other indoor air quality factors in addition to using a MERV 11 filter, you can create a healthier and more comfortable living environment for you and your family.

Using a Merv 11 Filter in the Wrong Climate

The Merv 11 filter is a popular choice for home air filtration, but it may not be the best option for every climate. In fact, using a Merv 11 filter in the wrong climate could do more harm than good.

In areas with high humidity, using a Merv 11 filter can actually cause mold growth. This is because the filter does such a good job of trapping particles that it can also trap moisture, creating an ideal environment for mold to grow. If you live in a humid climate, it may be better to use a Merv 8 filter instead.

On the other hand, if you live in a dry climate, a Merv 11 filter may be too much for your HVAC system to handle. The high level of filtration can restrict airflow, making your system work harder to push air through the filter. This can lead to increased energy costs and potential damage to your system over time. In a dry climate, a Merv 8 filter may be a better choice.

It's important to consider the climate in your region when choosing an air filter for your home. While a Merv 11 filter is a great option for many homes, it may not be the right choice for everyone. By taking into account the climate in your area, you can ensure that you're choosing the right filter for your home's needs.


Using a MERV 11 filter is a great way to improve the air quality in your home or workplace. However, to make the most of this filter, it's essential to avoid common mistakes such as failing to change it regularly and leaving gaps or leaks around the filter. By following these tips and tricks, you can ensure that you get the most out of your MERV 11 filter and enjoy the benefits of clean, fresh air.

Frequently Asked Question

A MERV 11 filter is a mid-range air filter, suitable for most residential and commercial buildings. It is ideal for households with pets or mild to moderate allergies or asthma. The MERV 11 filter is capable of trapping 85% of micron-sized airborne particles, which helps to improve indoor air quality and maintain the efficiency of the HVAC system. If you don't have any special needs, then a MERV 8 filter is usually sufficient.

The only standardized filter rating system is MERV, which stands for “minimum efficiency reporting value”. Developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers, the rating scale indicates how effectively a filter can stop particles from entering your home. The higher the MERV rating, the better the filtration and the more the HVAC system needs to work to overcome the filter’s back pressure.

For residential and commercial use, MERV ratings 8 to 13 are best. MERV 4 to 6 are only suitable for industrial applications, while MERV 14 to 20 are used primarily in hospitals and laboratories. HEPA filters, which aren’t included in the MERV rating system, are equivalent to a MERV 17 to 20 rating. Lastly, there are other rating systems like MPR (Microparticle Rating) and FPR (Filter Performance Rating) but these are not independent consumer standards.

When it comes to choosing the right furnace filter for your home, there’s no one-size-fits-all answer. To ensure that you make the best choice for your specific needs, you must consider various factors such as price, size, brand, and, most importantly, the MERV rating.

MERV stands for Minimum Efficiency Reporting Value, which is a rating system from 1 to 16 used to indicate how well the filter can capture airborne impurities. A MERV rating of 1 indicates the lowest efficiency, and 16 indicates the highest. MERV 8 and MERV 11 are two of the most popular ratings for residential use, as they are effective at trapping a majority of airborne particles.

So, which is better — MERV 8 or MERV 11? A MERV 8 filter is more affordable and perfect for filtering out large particles, but won't be as effective at capturing odors or small particles as a MERV 11 filter. MERV 11 filters are more expensive, and need to be replaced more often due to clogging, but can effectively reduce odors and capture small particles.

For the homes located in a polluted area, or those with pets or family members with allergies, a MERV 11 filter is the best choice. But if you don't fit into either of those categories, then a MERV 8 filter should suffice.

It is essential to keep in mind that the MERV rating for a filter is its minimum performance, and choosing the right one for your home will ensure that your HVAC system is functioning optimally.

Are you wondering what the difference is between MERV 11 and 13 furnace filters? Let us break it down for you.

MERV 11 filters are the most popular among residential users, and they can trap the majority of harmful contaminants in the air – this includes pollen, dust, lint, mold, dust mites, smoke, pet dander, and smog.

On the other hand, a MERV 13 filter is capable of capturing all of the particles that the 11 can, plus bacteria and viruses. This is due to its higher efficiency of particle arrestance (98%) compared to the 11 (90%).

When it comes to which one is better, it really depends on your needs. A MERV 11 is good enough for those living in moderately polluted areas, or those with mild allergies. But if you're in a heavily polluted area, or suffer from severe allergies/asthma, or own multiple pets – then the MERV 13 is the way to go.

No matter which rating you pick, it's important to remember to replace your filter periodically. Doing so will help ensure that your furnace remains in top shape for years to come.

MERV 11 air filters are more effective than MERV 8s, trapping smaller particles like pet dander, dust mites, auto-emissions and lung-damaging dust. This makes them a great choice for households with pets or those wanting improved air quality. It's also the most popular air filter option.

If you're looking for a middle-ground between MERV 8 and 13, MERV 11 is the perfect option. It’s more efficient than the 8, but cheaper than the 13, and won’t put extra pressure on your furnace due to its less dense material. Your furnace will last longer and your air will be healthier!

Before settling on a MERV rating, check your furnace's manual or info stickers to see what its max MERV rating is. Selecting an air filter with a higher rating than your system can handle can cause your furnace to work harder, increasing the risk of a breakdown.

MERV ratings are a standard that measure how well air filters work. The higher the rating, the finer the filtration, meaning fewer allergens, dust, and other contaminants can get through. Filters are tested for things such as pollen, dust mites, mold spores, pet dander, bacteria, tobacco smoke, and more.

Merv 8, 11, and 13 filters should be changed at least every three months. This is to ensure that your system doesn't get clogged, reducing its efficiency or damaging it. However, changing your filter every two months will give you even better filtration and healthier air in your home.

In short, the more often you change your MERV 11 filter, the better. A recommended minimum is every three months, but changing it every two months is even better for your home's air quality.