Are You Aware of the Health Risks of Using an Air Filter with a Low MERV Rating?

Did you know that the air inside your home could be two to five times more polluted than the air outside?

That's why air filters are so important. They help remove harmful particles from the air and keep you and your family healthy. But not all air filters are created equal. Some have a low Minimum Efficiency Reporting Value (MERV) rating, which can pose serious health risks.

In this article, we'll explore what MERV ratings are, why they matter, and the health risks associated with using a filter with a low MERV rating. So if you're concerned about the air quality in your home, keep reading!

What is a MERV rating and how is it measured?

A MERV (Minimum Efficiency Reporting Value) rating is a measure of an air filter's ability to capture different sizes of particles. Air filters capture particles that float in the air, such as pollen, dust, pet dander, and other pollutants. The MERV rating indicates the ability of an air filter to capture these particles, with a higher rating indicating better filtration performance.

The MERV rating is determined by subjecting the air filter to a standardized testing process. The test measures the filter's efficiency at capturing particles between 0.3 and 10 microns in size. The particles used in the test range from larger particles such as sand and pollen, to smaller particles like smoke and bacteria.

The air filter is rated on a scale of 1 to 20, with higher ratings indicating better filtration performance. For instance, a MERV rating of 8 is good for households with fewer allergies, while a rating of 13 is recommended for households with pets or allergies. It is essential to select the correct MERV rated air filter for your home or office to ensure that it performs efficiently.

In conclusion, understanding the MERV rating system allows you to make informed decisions when purchasing air filters. Remember to choose an air filter with a MERV rating suitable for your specific needs to ensure that the filter effectively captures airborne pollutants and promotes healthy air quality.

How a low MERV rating can impact your health

When it comes to air filters, the MERV rating is an important factor to consider. MERV stands for Minimum Efficiency Reporting Value and rates the filter's ability to capture airborne particles. Filters with a low MERV rating, such as those commonly found in homes and offices, may not be effective in capturing tiny particles that can have a huge impact on your health.

These particles can include pollen, dust, pet dander, and mold spores. Exposure to these particles can lead to a variety of health issues, including allergies, asthma, and other respiratory problems. Poor indoor air quality can also exacerbate existing health conditions, making it especially important for those with allergies or asthma to use air filters with a higher MERV rating.

Additionally, low-rated air filters may not be able to capture bacteria and viruses, making it easier for illnesses to spread throughout a building. This can be especially problematic in large office buildings or schools where many people are in close proximity.

Investing in a higher-rated air filter with a MERV rating of at least 11 can help ensure that you and those around you are breathing in cleaner, healthier air. By capturing more particles, this type of filter can also help improve the lifespan of your HVAC system, saving you money in the long run.

Don't underestimate the impact of your indoor air quality on your health. By choosing the right air filter with a high MERV rating, you can help protect yourself and those around you from the negative health effects of airborne particles.

The Benefits of Using Air Filters with High MERV Ratings

If you're looking to improve your indoor air quality and reduce health risks, using air filters with high MERV ratings is a wise choice to make. Here are some of the benefits you can enjoy:

1. Improved air quality: Air filters with high MERV ratings can capture a wide range of airborne particles, such as pet dander, pollen, and microorganisms. This means the air you breathe is cleaner and healthier.

2. Better allergy and asthma management: If you or any family member suffers from allergies or asthma, a high MERV rating air filter can help reduce symptoms by removing allergens and irritants from the air.

3. Enhanced HVAC performance: When you use air filters with high MERV ratings, they can help prolong the life of your HVAC system by preventing dirt and debris from building up in the system. This ensures that your heating and cooling systems work more efficiently and save you money on energy bills.

4. Increased comfort: Air filters with high MERV ratings are designed to trap more pollutants and allergens, leaving your indoor environment cleaner and more comfortable. You may notice a significant reduction in odors, dust, and other irritants when you use a high-quality air filter.

There are many different types of air filters available in the market, and choosing the right one for your home or office can be overwhelming. But when it comes to reducing health risks and improving indoor air quality, investing in air filters with high MERV ratings is a smart move that you won't regret.

The Different Types of Air Filters and Their MERV Ratings

Air filters come in different types, and each one has its own MERV rating. Understanding these ratings can help you choose the right filter for your needs.

Fiberglass Filters

Fiberglass filters are the most common and cheapest air filters in the market. They are made of spun fiberglass threads that capture large particles such as dust and lint. However, they have a low MERV rating of 1-4, making them less efficient in removing smaller particles such as pollen and mold spores.

Pleated Filters

Pleated filters have a higher MERV rating of 5-13 and capture smaller particles such as mold spores, pollen, and pet dander. They are made of folded sheets of polyester or cotton, and their compact design allows them to fit into smaller HVAC systems.

HEPA Filters

HEPA filters have the highest MERV rating of 17-20 and can capture particles as small as 0.3 microns. They are made of tightly packed fibers that create a maze-like structure that traps even the smallest airborne particles. HEPA filters are popular in hospitals, laboratories, and other places that require a high level of air filtration.

When choosing an air filter, consider the MERV rating and the type of filter that best suits your needs. The higher the MERV rating, the better the filtration efficiency, but keep in mind that higher-rated filters may also reduce the airflow in your HVAC system, so it's essential to find a balance that works for you.

5 Tips to Maintain Your Air Filter and Ensure Optimal Air Quality

Regular maintenance of your air filter is crucial to ensure optimal air quality in your home. Here are five tips to help you maintain your air filter and improve your indoor air quality:

1. Change or Clean Your Filter Regularly: Depending on usage and the filter type, it's recommended to change or clean your air filter every 1-3 months. A dirty or clogged filter can reduce the efficiency and effectiveness of your air filter, leading to poor air quality in your home.

2. Check for Air Leaks: Air leaks can reduce the performance of your air filter by allowing unfiltered air to enter your home. Check for air leaks around doors, windows, and vents, and seal them with weatherstripping or caulking to improve your air quality.

3. Use High-Quality Filters: Choose filters with a high Minimum Efficiency Reporting Value (MERV) rating to trap smaller particles and improve air quality. Consider upgrading to a HEPA (High-Efficiency Particulate Air) filter for the best filtration performance.

4. Keep Your Air Filter Housing Clean: A clean filter housing can improve the performance and lifespan of your air filter. Regularly vacuum or wipe down the housing to remove any dust or debris.

5. Maintain Proper Ventilation: Proper ventilation can help improve air quality by circulating fresh air throughout your home. Open windows and doors for natural ventilation or consider installing an air exchange system to provide consistent fresh air circulation.

By following these tips, you can maintain your air filter and ensure optimal indoor air quality for you and your family.


It’s important to remember that not all air filters are created equal. A low MERV rated air filter might seem tempting due to its affordable price tag, but it could potentially cost you in the long run with health risks associated with poor indoor air quality. It’s crucial to invest in a high-quality air filter that will keep you and your family healthy in the long run. Make sure to check the MERV rating before purchasing any air filter and consult with an HVAC professional to ensure you are selecting the best option for your home.

Don’t take unnecessary risks when it comes to your health. Make the smart choice and choose an air filter with a high MERV rating for a cleaner and safer environment.

Frequently Asked Question

MERV stands for Minimum Efficiency Reporting Value - a scale created by ASHRAE to measure the effectiveness of filters in removing different sized particles. For example, a MERV-13 filter is designed to catch 90% of particles 3-10 µm in size, 85% of particles 1-3 µm in size (PM2.5), and 50% of particles 0.3-1 µm in size. Generally, filters with higher MERV ratings are better at catching higher percentages of particles, including the smaller ones.

When you install a filter in the airstream, it will create resistance. The amount of resistance depends on the type of filter material and the amount of area it covers. Standard fiberglass filters don’t generate much resistance, though it increases as the filter gets dirtier. To remove more pollutants from the air, you can use a filter with a different material such as a high MERV filter. These filters have smaller pores, which allow them to catch more pollutants, but also create higher resistance.

The problem with this is that the blower and furnace are only designed to handle a certain amount of pressure drop. Too much resistance means the air flow is low, making the heat exchanger get hotter and potentially crack. On the plus side, low air flow can result in better dehumidification in humid climates, as long as the air flow isn’t so low that it turns the condensate to ice.

So, the answer to the question is: yes, higher MERV filters are better, but you need to find the right balance between air flow, resistance, and effectiveness.

Air filters are designed to capture airborne particles, which can be anything from dust and pollen to mold spores and bacteria. The filter works by drawing air through itself and trapping the particles in the web of fibers that make up the filter.

What are the types of air filters

There are many different types of air filters available on the market. The type of filter you need will depend on the specific needs of your facility. Some common types of air filters include MERV, HEPA, activated carbon, and ultraviolet (UV) germicidal irradiation.

MERV: MERV stands for Minimum Efficiency Reporting Value. MERV ratings range from MERV-0 to MERV-16. The higher the MERV rating, the more efficient the filter is at capturing particles.

HEPA: HEPA filters are a type of air filter that is designed to capture very small particles. A true HEPA filter has a MERV rating of 17-20.

Activated carbon: Activated carbon filters are designed to remove gases and odors from the air.

UV germicidal irradiation: UV germicidal irradiation is a type of light that is used to kill bacteria and viruses.

There are pleated filters and panel filters. MERV 13 filters are pleated, while MERV 16 filters can be either pleated or panel. Pleated filters have more surface area because they are made up of multiple layers of filter media. The pleats create more space for the air to flow through, and the more layers of filter media there are, the more particles can be captured.

HEPA filters are usually pleated, but they can also be panel.

What are the differences between MERV 13 vs HEPA filters

While MERV 13 and HEPA filters both remove particles from the air, they work in different ways.

MERV 13 filters are designed to remove particles that are larger than 0.30 microns, while HEPA filters are designed to remove particles that are smaller than 0.30 microns. MERV 13 filters are often used in commercial and industrial settings, while HEPA filters are often used in hospitals and other medical settings.

MERV 13 filters are more efficient at removing large particles from the air, while HEPA filters are more efficient at removing small particles from the air. MERV 13 filters can remove up to 99.97% of particles from the air, while HEPA filters can remove up to 99.99% of particles from the air.

MERV 13 filters are less expensive than HEPA filters, and they can be used in a wider variety of settings. However, HEPA filters are more effective at removing small particles from the air, and they can be used in settings where MERV 13 filters cannot.

MERV and HEPA filters both work to capture airborne particles, but they do so in different ways. MERV 13 filters are designed to capture particles larger than 0.30 microns, while HEPA filters are designed to capture particles smaller than 0.30 microns. MERV 13 filters are more efficient at removing large particles from the air, while HEPA filters are better at capturing small particles. 

MERV 13 filters are less expensive and can be used in a wider variety of settings, but they can only remove up to 99.97% of particles from the air. On the other hand, HEPA filters are more expensive but can remove up to 99.99% of particles, making them ideal for medical settings. In short, MERV 13 filters are great for everyday use, while HEPA filters are better for specialized environments.

Your HVAC system includes a furnace, air conditioner, or heat pump. It's essential to keep these systems clean and efficient by regularly replacing the air filters. To do this, you'll need to know about MERV ratings.

The air filter in your HVAC system serves two key functions: it protects your system from dust, and it helps clean the air in your home. When the filter is clogged, dust can build up in the system, and the equipment may overheat and fail.

How often the air filter needs to be changed depends on your home's size, where you live, and if you have pets. Inspect it every month, and replace it when you can't see the filter material through the dust.

When choosing an air filter, refer to the specifications of your HVAC system to determine the size. The MERV scale is used to measure the filter's ability to remove particles from the air, and ratings range from 1 to 20, with lower ratings meaning lower-quality filters.

Remember to balance air cleaning with air flow when upgrading your filter to a higher MERV rating. Too dense of a filter can cause air flow restriction and harm your system. Ask your HVAC technician for advice when in doubt.

Replacing the air filter is easy. Open the blower compartment located between the air return and the furnace or air handler. Put the used filter in a plastic bag, then insert the new filter with the arrows pointing in the direction of the airflow.

MERV 11 filters used to be thought of as air flow restrictors, but this is no longer necessarily the case. Home Energy's 2009 experimental test concluded that the pressure drop of high-MERV filters isn't as severe as it used to be. If you're renting and don't have any special needs, then a standard, cheap fiberglass filter with a cardboard frame is fine to use every three months. But if you own your home, then it's worth investing in a more durable filter.

Pleated filters with more pleats per foot are the better option and should be more effective at improving indoor air quality. However, the price can be an issue. A standard 16x25x1 11 MERV filter will cost around $5, but you can save a bit if you buy them in packs of 12. Filtrete, Purolator, and Nordic Pure are all trusted brands.

If you plan to buy washable filters, be aware that cheaper models may have loose filter media after washing and won't perform as well. Disposable filters are also more hygienic since they remove all the dirt from the air. Keep in mind that the more pleats per foot, the better the filter will be.

So, when it comes to MERV 11, the issue of air flow restriction isn't as big as it used to be. With the right filter, you can improve your indoor air quality without having to worry about a pressure drop. Make sure to replace your filter every three months for the best performance.

MERV ratings are used to compare filters to determine which is most effective for eliminating pollutants in a home or office. The American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) developed the Minimum Efficiency Reporting Value (MERV) system to measure how well an air filter captures common airborne particles. There are 16 MERV values, ranging from 1 to 16, and the efficiency increases with the MERV number.

Filters are tested against 12 size ranges of particles, with the smallest being around 0.3 microns and the largest around 10 microns. To give a sense of the size, a micron is one millionth of a meter and a strand of human hair is approximately 75 to 100 microns.

The MERV rating is determined by measuring the particle count upstream and downstream of the filter being tested over six intervals, beginning with a clean filter. Afterward, a special ASHRAE test dust is added for five additional measurement cycles. The filter’s performance is determined by calculating the particle density before and after passing through the filter, and then assigning a MERV rating.

The MERV 8 filter is the most common filter in the U.S. Understanding how MERV ratings work can help you understand why it's so popular and how to choose the most beneficial filter for your needs.