Which is Better for Your HVAC System: HEPA or MERV Filters?
Know the meaning of various HEPA and MERV ratings before you buy your next HVAC filter.
Considering how much time the average American spends indoors, having good indoor air quality is no doubt important, both for your health and for your comfort. While many factors affect air quality, filtration is definitely one of the most important. Without adequate filtration, you’ll end up with high amounts of airborne contaminants like:
- Dust
- Dust mites
- Pollen
- Pet dander
- Mold
- Skin flakes
- Viruses
Of course, not all filters are created equal. Before you purchase your next HVAC filter, make sure you understand how it affects your indoor air quality and energy efficiency.
What is MERV?
Most residential HVAC filters carry MERV ratings. MERV stands for Minimum Efficiency Reporting Value. This is not to say that MERV filters are poor quality in reality they are more than adequate for the needs of most homeowners. Just be sure to remember that the higher the MERV rating, the better the filtration. A filter with a MERV rating of 13 to 16 is considered a high-ranking MERV filter and can remove up to 75 percent of all airborne particles 0.3 microns or greater from the air.
What is HEPA?
HEPA, or High Efficiency Particulate Air filters, are designed for applications where contaminants must be trapped on the first go round. For example, you wouldn’t want viruses circulating in the air in a hospital, so the facility would probably be equipped with HEPA filtration. HEPA filters can capture up to 99.7 percent of all contaminants 0.3 microns or greater using a dense mat of fibers arranged in a specific configuration. Some particles naturally adhere to the fibers when they hit, while others get trapped by the curved contours of the fibers. The remaining particles are trapped when they are forced to collide with gas molecules in the filter. This high particle capture rate comes at a cost HEPA filters present more resistance to air flow than MERV filters. This means the blower on your HVAC equipment has to work harder to push air through the filter and therefore uses more energy.
Which is Better?
In the end, the decision of which filter to get will come down to your own specific needs. In most cases, you can strike a good balance between air cleanliness and HVAC efficiency with a MERV-rated filter. Remember that the air in your home is recirculated, so the same air will pass through your filter multiple times each day. After several rounds, each of which captures up to 75 percent of airborne particles, your air will get plenty clean, without requiring the extra energy that HEPA filtration would.
by HEPACART on Apr 11, 2023
If you want to improve your facility's indoor air quality (IAQ), you will quickly learn that you can choose from multiple air filters. Air filters are designed to pull indoor air through their system and trap any harmful particles within their fibers. Numerous facilities and businesses use air filters to prevent the spread of bacteria and keep their people healthy. Two of the most popular air filters are MERV 13 and HEPA filters. Not all filters will work the same or have the same efficiency level. Let’s examine the differences between the two and why one may be better suited for your facility.
What is a MERV Filter?
A filter’s minimum efficiency reporting value, or MERV, is a rating system that measures how efficient a system is at trapping harmful particulate matter, dust, and debris that roams throughout the air. Generally, it is used to compare different filters. This system categorizes filters into a ranking from 2 to 20, with a MERV 8 being the standard. A higher MERV rating means that a system is more efficient. MERV 13 is recommended for many commercial and industrial buildings. At its minimum, a MERV 13 filter traps less than 75% of air particles that are 0.3 to 1.0 microns in size. It is at least 90% effective when the particles increase to 3 to 10 microns in size.
This budget-friendly option works to prevent contaminants from spreading throughout a building. However, if you are trying to determine which MERV filter is best for your building, do not assume that a higher ranking is the best option. Your HVAC system may not be designed to handle much air resistance. With a higher ranking, you will find that these filters have smaller pores, making it difficult for clean air to pass through smoothly. Make sure you choose a filter that will be compatible with your HVAC system.
What is a HEPA Filter?
A high-efficiency particulate air (HEPA) filter targets the tiny particles within the air to help promote proper IAQ. Most HEPA filters are pleated and typically made of borosilicate glass, plastic, or fiberglass fibers. Trapping the particulate matter in the filter can greatly reduce the number of harmful particles in the air. These mechanical filters can remove particles smaller than 0.30 microns at a 99.97% efficiency, making them the perfect filter for healthcare and educational facilities. All HEPA filters have a MERV rating of 17 or higher.
HEPA filters capture unwanted particles in one of three ways. Impaction occurs when particles crash into the surface of the filter. Typically, larger particles, 1 micron or bigger, are captured through this method. An interception occurs when the particles successfully pass through the screen and into the filter. Fibers intercept the particles and remove them from the air. Diffusion is the final attempt to remove particulate matter from the air. Gas molecules will move through the filter, causing the particles to crash into fibers. When this happens, they are permanently trapped and unable to continue their journey.
Core Differences
The American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) developed the MERV charts in 1987. When the MERV rating system was created, it did not go high enough to include HEPA filters. It only exceeded a MERV 17, meaning anything greater was classified as HEPA. Over time, higher levels have been added to include these extremely proficient filters. MERV 13 filters are excellent at removing large particles, while HEPA filters trap small particles more efficiently.
Another difference between a MERV filter and a HEPA filter is the cost. Generally, a HEPA filter will have a higher price tag but are more beneficial for construction zones, medical facilities, and educational facilities. A standard office or department store can run smoothly on a MERV filter alone, but a HEPA filter is the better choice when you are worried about the health of those within your facility.
Best HEPACART® Dust Containment and Air Filtration Systems for Your Working Area
When looking for an indoor air filtration system to improve your facility’s IAQ, you must ensure the equipment will be compatible with your HVAC system. Plus, the system will need to work at an efficiency level appropriate for your facility’s use. Healthcare or educational facilities require a more robust and efficient system than a standard commercial or industrial building. If you need a powerful system to help your facility have better IAQ, investing in equipment that uses HEPA filters is a great place to start. At HEPACART®, we provide dust containment, air filtration, and surface disinfection solutions to keep people safe in high-risk environments.
HEPACART Mobile Containment Cart
Mobile containment carts provide dust containment and infection control in high-risk environments. Healthcare contractors designed the HEPACART® Classic and Auto Lift for healthcare contractors. These ceiling access carts have an embedded, fully tested, and certified negative air machine. Both utilize HEPAFORCE technology to clean the air within an area by efficiently removing dust.
HEPAFORCE® Air Filtration
When you need to clean and disinfect the air within your facility, our air filtration and purification machines are a great solution. To clean the air in a confined area, it creates positive or negative air pressure to disinfect and promote good IAQ. The health of those within your facility should be a priority, and there are harmful particles that can be a threat to their health. A GermBuster can prevent infection and particulate matter from spreading.
Protect Your Facility
Taking steps toward better IAQ can seem overwhelming. Knowing which option is best for your facility can be difficult with so many choices and products. However, investing in air filtration solutions that will protect your facility and those in it is one of the most important things you can do as a facility manager. Air filtration can keep bacteria, dust, and harmful particles out of the air, so workers can do their jobs distraction-free. To learn more about what HEPACART offers, download our product pricing guide here.