Most people have heard of MERV ratings but might not know what they are. MERV stands for Minimum Efficiency Reporting Value and is a rating system used to measure the effectiveness of HVAC air filters. The higher the MERV rating, the better the filter is at trapping tiny particles from the air.
Here I’ll have MERV rating explained, what MERV is and how it works, as well as give you an idea of which ratings are appropriate for different applications. In my experience as a mechanical engineer working in the HVAC industry in Manhattan, the appropriate filter MERV rating can vary greatly depending on the specific situation, so it’s important to understand it and what it affects.
What Is MERV?
As explained above, MERV is a rating system developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to evaluate how effectively an air filter removes particles from the air stream.
The higher the MERV rating, the more efficient the air filter is at removing particles. However, it’s important to note that as efficiency increases, airflow decreases. That’s why choosing an air filter with a MERV rating that meets your specific requirements is important.
Understanding the MERV Rating Chart
To understand how the MERV rating chart works, you need to know a little about air filters and how they remove contaminants from the air.
Air filters are designed to trap particles in the air, such as dust, pollen, and pet dander. The size of the particle is measured in microns, and the smaller the micron, the more efficient the filter will be at trapping it. The MERV rating measures the smallest particle size that a filter can trap and still allow airflow through it.
The higher the MERV rating, the more efficient the filter will be at trapping smaller particles. However, the higher the MERV rating, the more resistance there is to airflow. This means that your HVAC system will have to work harder to push air through the filter, which can lead to higher energy bills.
To find the right balance for your home, you’ll need to consider the types of contaminants in your air and how much airflow you need. For homes with pets or people with allergies, a higher MERV rating may be necessary to trap all of the allergens and keep them out of the air. However, a lower MERV rating will be sufficient if you don’t have any major concerns about air quality.
MERV Rating Scale
The MERV rating scale goes from 1 to 16:
- MERV 1-4: These filters are typically used in residential settings. They’re designed to remove large particles, such as dust, pollen, and mold spores.
- MERV 5-8: These filters are often used in commercial settings, such as office buildings and hospitals. They’re effective at removing smaller particles, such as bacteria and viruses.
- MERV 9-12: These filters are typically used in industrial settings, such as factories and laboratories. They can remove very small particles, such as smoke and fumes.
- MERV 13-16: These filters are used in cleanroom applications, such as those found in the semiconductor industry. They can remove extremely small particles, such as viruses and bacteria.
Looking for a specific MERV rating air filter? Here’s our complete guides if you are looking for:
- The Best Merv 8 Air Filters
- The Best Merv 11 Air Filters
- The Best Merv 13 Air Filters
- The Best Merv 14 Air Filters
- The Best Merv 16 Air Filters
How Is MERV Used?
The MERV rating is used to help determine the most appropriate air filter for a given application. When choosing an air filter, it’s important to consider both the desired level of filtration and the potential impact on airflow.
For example, a home with pets may benefit from a filter with a higher MERV rating to remove pet dander from the air. However, if that same filter also decreases airflow too much, it could create problems for the home’s HVAC system.
Pre-Filters vs Final Filters
Most HVAC systems have two types of filters: a pre-filter and a final filter. The pre-filter’s job is to protect the final filter from larger particles that could clog it. The final filter’s job is to remove smaller particles, like dust and pollen, from the air.
There are several benefits to using both a pre-filter and a final filter in your HVAC system. First, it can prolong the life of your final filter by protecting it from larger particles. Second, it can improve the efficiency of your HVAC system by allowing it to run for shorter periods of time. And third, it can enhance the air quality in your home by removing more particles from it.
If you’re considering using a pre-filter and a final filter in your HVAC system, there are a few things to remember.
- First, you’ll need to choose the right size filters for your system.
- Second, you’ll need to decide how often to change the filters.
- Third, you’ll need to make sure that the filters are installed correctly.
The size of the filter is important because it needs to be able to capture all of the particles that pass through it. If the filter is too small, some particles will escape and eventually end up in your home’s air. If the filter is too large, it will restrict airflow and can cause your HVAC system to work harder than it needs to.
The frequency with which you need to change the filters will depend on the type of filter and the level of use your HVAC system gets. For example, if you have a pleated air filter, you’ll probably need to change it every three months or so. But if you have a cartridge air filter, you might be able to go six months or more between changes.
Finally, it’s important to ensure the filters are installed correctly. If they’re not, they won’t be able to do their job correctly. Ensure that the filters fit snugly in their housing and that they’re not blocked by anything.
If you follow these tips, using a pre-filter and a final filter in your HVAC system can be a great way to improve the air quality in your home and prolong the life of your system.
MERV Filter Ratings and Efficiency
Higher efficiency comes at a cost. Filters with higher MERV ratings typically have a smaller surface area and therefore need to be replaced more often. They also tend to be more expensive.
What Are the Benefits of Using a High-Efficiency Filter?
There are several benefits to using a high-efficiency filter:
- Higher efficiency filters trap more particles, which can improve indoor air quality.
- They can help to prolong the life of your heating and cooling system by trapping smaller particles that can clog the system.
- They can save you money on your energy bill by allowing your system to run more efficiently.
What Are the Disadvantages of Using a High-Efficiency Filter?
There are also some disadvantages to using a high-efficiency filter:
- Higher efficiency filters need to be replaced more often, which can be costly.
- They can put a strain on your heating and cooling system if they are not properly sized or installed.
- They can create harmful ozone if used in an electronic air purifier.
MERV Filter Ratings and Air Quality
Air quality is important for both our health and comfort. Poor air quality can cause various respiratory problems, including asthma and allergies. It can also make breathing difficult, cause headaches, and make us feel fatigued.
There are a few things that you can do to improve your indoor air quality, such as using an air purifier or opening windows to let in fresh air. Another option is to use filters with a high MERV rating.
MERV 8 filters are great for removing pollen, dust mites, and pet dander. MERV 11 filters are even better at removing these contaminants and mold spores, and smoke particles.
If you’re looking for the best air quality possible, choose a filter with a MERV rating of 13 or higher. These filters are often used in hospitals and other commercial buildings because they are excellent at removing contaminants from the air.
No matter what your air quality needs are, there’s a filter with a MERV rating that can help. Choosing the right filter can improve your indoor air quality and breathe easier.
What Level of Filtration is Needed?
As you know, the quality of the air you breathe directly impacts your health. While most people are aware of the importance of indoor air quality, they may not be as familiar with the different types of HVAC filtration available to them.
There are many factors to consider when choosing the right level of HVAC filtration for your home or business. The first is the type of contaminants you are trying to remove from the air.
Each type of contaminant requires a different type of filter to effectively remove it from the air. For example, a pleated paper filter will do a better job of removing larger particles, such as dust and pollen. In contrast, a HEPA filter will be more effective at removing smaller particles, such as smoke and mold spores.
The second factor to consider is the size of the space you are trying to filter. A smaller space, such as a single room, can usually be effectively filtered with a portable air purifier. However, larger spaces, such as an entire home or office building, will require a more powerful system, such as a whole-house or commercial HVAC filtration system.
When it comes to choosing the right level of HVAC filtration for your home or business, there are many factors to consider. The type of contaminant you are trying to remove, the size of the space you are trying to filter, and the level of filtration you need will all play a role in determining the best solution for your needs.
Contact a professional if you are unsure which type of HVAC filtration is right for your home or business. They will be able to help you choose the right system for your specific needs and ensure that it is installed properly to provide the best possible air quality for your family or employees.
Question: Can HVAC systems slow down COVID-19?
Answer: Yes, HVAC operations strategies can help prevent the spread of COVID-19. The most important strategy is ensuring that the ventilation system is operating properly and that air is circulated throughout the building or home. Other strategies include increasing the fresh air coming into the building, using HEPA filters, and using ultraviolet germicidal irradiation.
The coronavirus pandemic has resulted in a great deal of uncertainty for businesses and organizations around the world. One of the most pressing questions has been how to keep employees safe and healthy in the workplace. For many organizations, this has meant reevaluating their HVAC systems and operations strategies.
In fact, the US Centers for Disease Control and Prevention (CDC) has released guidance specifically on the importance of HVAC systems in preventing the spread of the virus.
Question: What MERV filter can prevent airborne illnesses like COVID-19?
Answer: MERV 13 filters are recommended for preventing the transmission of airborne illnesses such as COVID-19. MERV 13 filters are able to capture particles as small as 0.3 microns, making them very effective at trapping viruses and bacteria. In addition, MERV 13 filters have a higher air flow rate than other filter types, meaning they can more easily handle the increased airflow rates associated with respiratory illnesses.
There are a few different ways to choose a MERV filter, but the easiest way is to simply look for a filter that is rated 13 or higher. This will ensure that you get a filter capable of capturing small particles while also providing good airflow.
So, Should I Buy Filters with High MERV Ratings?
Now that you know what MERV ratings are, you may be wondering if you should buy filters with high MERV ratings. The answer to this question depends on a few factors.
- First, it’s important to understand that not all air filters are created equal. Some air filters have better designs than others, which means they can remove more particles from the air even if they have a lower MERV rating.
- Second, it’s also important to consider your specific needs. For example, you may need a filter with a higher MERV rating to remove more allergens from the air if you have allergies or asthma.
- Third, it’s also worth considering the cost of filters with high MERV ratings. Generally, these filters are more expensive than those with lower ratings.
- Finally, it’s important to remember that even the best air filter won’t remove all particles from the air. That’s why it’s also important to focus on other things that can help improve indoor air quality, such as ventilation and keeping your home clean.