merv rating merv filter pressure drop chart

At the lower end of the efficiency spectrum a fiberglass or polyester panel filter may have a MERV of 4 or 5. MERV stands for Minimum Efficiency Reporting Value. When a filter is in use, it traps and gathers particles, the more particles that are trapped the harder it is for air to pass through; when this occurs the filters pressure drop rises. "text": "Static pressure is the measurement of the exertion of air flow your HVAC system is moving throughout the system and ductwork." Pressure drop directly corresponds to a filters air flow rate." MERV stands for Minimum Efficiency Reporting Value. Each filter is assigned a rating based on how much debris a filter manages to block when circulating air. But lets start with what kind of particles are between 0.3 and 10 microns: Lets look at examples of two filters with 10 MERV and 14 MERV ratings. So, you just purchased some new filters for your home HVAC system. They are available for the home and business. "@type": "Answer", Below is a chart comparing the pressure drop of standard 20X24X1 MERV8, 11, and 13 at 1000 CFM. The COVID-19 pandemic has caused concerns about data center HVAC (heating, ventilation and air conditioning) filtration. } It is measured in Pascals in the SI system. 99.97% or better for all particle sizes). The amount of E1, E2 and E3 dust particles that are captured and missed is calculated. "@type": "Answer", If you dont have, or cant find, the owners manual for your HVAC system, here are the recommendations of three agencies. MERV values range from 1 (minimal filtering) to 20 (maximum filtering). You can help minimize the risk of HVAC equipment issues or damage from pressure drop, by regularly changing your air filter. Q&A Debunking Myths About MERV, Air Filtration . MERV, which is an acronym for Minimum Efficiency Reporting Value, is a rating system that was developed by ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers). MERV stands for Minimum Efficiency Reporting Value. An official website of the United States government. Particles that are larger or smaller are trapped with even higher efficiency. Includes a moisture resistant, high wet-strength beverage board frame. The minimum efficiency reporting value, is a number from 1 to 16 that is relative to an air filter's efficiency based upon particle size. When a filter is in use, it traps and gathers particles, the more particles that are trapped the harder it is for air to pass through; when this occurs the filters pressure drop rises. This allows greater airflow without having to increase the size of the actual filter. In particular, using an air cleaner with a MERV rating that is too high can damage the compressor, heat exchanger, and air conditioner coil. 3M Pro Series Residential Air Cleaning Filters 4" and 5" filters last up to 6 to 12 months. The difference between the FPR and MERV ratings is that FPR uses a scale of 1-10, while MERV uses a scale of 1-16. In January 2009 ASHRAE stopped recognizing MERV 17 -20 values. (State-By-State Chart), How To Convert Therms To kWh? The pressure drop across the MERV-13 filter was 0.0274 inch of water column. "name": "What pressure drop is safe for my AC/Air Handling System? Depending on what size of particles the air filters can trap or let through, they are classified in a chart known as the MERV rating. { When used as final filters, they are the primary filters for an HVAC system. },{ If I look at AprilAire's CFM table per product, it shows the following pressure drops in order from the 410, 413, and 416 models (i.e. M values 1 through 4 are designed to remove large particles. This type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3microns (m). "@type": "Answer", Hi, great article! Why? E2 arrestance is for the middle size particles. A: Our current recommendation is to use a filter with a Minimum Efficiency Reporting Value (MERV) of 13, but a MERV 14 (or better) filter Is preferred. We cannot assume that the two AHUs operate at the same airflows, so the costs normalized for airflow are best used to make an estimate of annual energy savings by using 5-Star air filters. In 2020, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommended switching from MERV 8 filters to MERV 13+ filters in order to help protect against the COVID-19 virus. "@type": "Question", Learn more about these recommendations here. The test results are then used to give a filter its MERV rating. As the MERV rating increases the media typically becomes loftier and thicker, to capture more air pollutants, with this you could see slightly more air restriction. The higher the MERV rating, the more particles the filter will remove. This helps improve indoor air quality and prevents the build up of contaminants in equipment and damaging it. } The higher the number, the better the filter is at capturing larger particles between 0.3 and 10 microns (m). } As air moves through a buildings HVAC system, air filters trap and collect large and small particles such as dust, allergens and microorganisms. Upgrade your filter to a MERV 13 rated air filter to protect your home or business from the spread of viruses and illnesses. This is how they get the name MERV (MINIMUM Efficiency Rating Value). This is one way a higher MERV filter can have a lower pressure drop than one with a lower MERV rating. A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. Simple use of MERV rating chart for air purifier filters: The higher the MERV rating, the better the filter. A filter's MERVnumber indicates how it's rated to remove these particles. MERV Rating Chart: How to Choose the Right Air Filter for You? ASHRAE stands for the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. "acceptedAnswer": { If you're looking at air filters rated for MPR compared to air filters rated by the MERV filter rating system, you can reference this chart below: MPR 600 is equal to MERV Rating 8; MPR 1000 is equal to MERV Rating 8; MPR 1200+ is equal to MERV Rating 11; MPR 1500 is . "text": "A filters pressure drop directly corresponds to a filters air flow rate. It isnt easy to navigate through 20 classes of MERV ratings. ; High-rated media is able to retain fumes . We are hiring! Many of our competitors claim read more. However, one study found that actual pressure drops in home. The MERV filter rating measures the amount of microparticles and macroparticles in the air from 0.3 microns and 10 microns in size. The following example illustrates how this can play out for a hospital investing in higher quality filters to reduce their energy and filter replacement costs. That will result in more resistance to air passing through it. },{ } "text": "Filters use various types of medias depending on the application or what the environment requires. MERV 9 through 12 filters are good filters for general home use. The filters initial pressure drop (initial resistance) will vary by the filter type, MERV rating, and size. This could be because your system is moving too much or not enough air through its ductwork." An air filters minimum efficiency reporting value (MERV) rating measures how effectively the filter stops dust and other contaminants from passing through the filter and into the air stream. The M in MERV rating stands for Minimum. As you can see, the HEPA filters surpass the most restrictive 0.3-1.0 micron particle size interval MERV rating is based upon. The test is made of six cycles. the expression of the Minimum Efficiency Reporting Value (MERV). Firing Ranges. All filters will increase in pressure drop in use. DC Wire Gauge Calculator: What Gauge Wire (12V, 24V, 48V)? },{ E1 particle ar .3 to 1 micron and they include bacteria and tobacco smoke. HEPA stands for High-Efficiency Particular Air. "text": "A filters pressure drop is measured twice, once when the filter is brand new and again when the filter has been in service and is loaded with trapped air pollutants. These air filters are used to protect people or products from airborne contaminants. MERV Ratings 17-20 reflect values that are used in the rating of HEPA and ULPA filters. For comparison, a grain of sand is about 60 microns. Activated carbon filtersremove VOCs and odors. This method tests Air-Cleaning Devices for dust removal efficiency. The higher the MERV, the more efficient the air filter is at removing particles. According to theAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),this filtration helps provide healthier indoor air quality. Weve got em. Depending on the design [] ", Generally, increasing filter efficiency leads to increased pressure drop which can lead to reduced air flow through the HVAC system, more . The chart below shows the MERV ratings. MERV stands for Minimum Efficiency Reporting Value. The MERV rating is determined by the size of the particles that the air filter can remove, with the smallest particles being the most efficient at removing. The US Department of Energy recommends at least a MERV 8. It should be noted that pressure drop through a high-MERV filter varies depending on the velocity of the air flow. Frequent filter changeoutsare necessary to reduce the possible negative effects a loaded filter can have on your HVAC equipment. It is a rating system incorporated into the test specification of ASHRAE 52.2. HEPA and ULPA filters are represented in the 17 through 20 ratings. Rooms will be too hot or too cold: This is a symptom of low airflow. You must have JavaScript enabled in your browser to utilize the functionality of this website. This MERV rating chart has the MERV ratings, 1-16 on the left hand column and then there are five other columns showing the average efficiency in microns, average arrestance and the final resistance as measured in inches of water. This guideline determines a filters performance by particle size. In case you havent heard of MERV before, it stands for Minimum Efficiency Reporting Value. Characteristics. A: There is evidence that HVAC operations may help decrease people's exposure to airborne pathogens that spread COVID-19 and other illnesses. "acceptedAnswer": { "@type": "Answer", Heres one example: We compared three filters of a popular brand and the same size (20x25x1) with MERV 5, MERV 11 and MERV 13 ratings. 11 filters 11 merv 13 filters 13 merv 8 filters air air filter air filters air flow air purifier air purifiers air quality airborne airborne particles airflow allergens allergies allergy as dust as merv asthma bacteria best air by particle carbon carbon dust clean cleaner cleaning covid dust dust mites dust particles electrostatic filter filter's filtering filters filters air filtration furnace filter hepa hepa filters higher merv higher merv rating home home air homes household humidifier dust indoor air insecticide dust is merv large particles lead dust manufacturer manufacturers manufacturing merv merv filter merv rating merv ratings merv scale merv stands microparticle performance rating mold mold spores more particles my filter particle particle size particles performance rating pharmaceutical manufacturing purifier purifiers rating rating chart ratings refrigerating and air room sanding dust small particles smaller particles smoke technology these filters these particles this filter this rating to air tobacco smoke usa virus viruses water filters what does merv which merv which merv rating. Minimum Efficiency Reporting Values, or MERVs, report a filter's ability to capture larger particles between 0.3 and 10 microns (m). They also found that airflow in the high MERV filters decreased by 7% and 11% in the two HVAC systems compared to the low MERV filters. Industrial Filtration Process: Why Its Important and Its Uses, How Often to Change a MERV 13 Filter: Everything You Need to Know, MERV 13 vs HEPA Filter (What Are The Differences? "acceptedAnswer": { Woodhead Publishing, 2017. While that can happen, it most likely will not be a result except under extreme circumstances involving a cheap blower motor and the concern addressed below. According to the standard's application guidelines, particles in this size range include pollen, dust mites, mold spores, hair spray, powdered milk, and of course, snuff. If U are going to use pleated filters U need a deep pleated filter to provide a lot more area; which would require new Return Air filter racks . What are the benefits of a higher MERV rating? W2 Wire Thermostat Wiring (2nd Stage), Thermostat Wire Color Codes For 3-8 Wire Thermostats (Color-By-Color), How Many Therms Of Gas Per Month Is Normal? For example, in order to achieve a MERV 13 value, the tested filter must be at least 50% efficient on dirt particles in the E1 range, at least 85% on E2 . CFM Calculator Calculate Clean Air Flow. In general, filters with a rating of MERV16 or below are considered to be HVAC-system-grade filters for residential, commercial and general hospital use. These filters capture particles at 10.0 microns in size, including pollen, dust mites, and carpet fibers. When selecting the right filter for your application, higher is not always better. Resistance is measured in inches water gauge (w.g.) These values are shown to reflect the common vernacular used by many players in the filtration industry, Generally, the higher the MERV (M), you get better filter performance. The possible air speeds used for testing is as follows: 118 FPM (0.60 m/s)246 FPM (1.25 m/s)295 FPM (1.50 m/s)374 FPM (1.90 m/s)492 FPM (2.50 m/s)630 FPM (3.20 m/s)748 FPM (3.80 m/s). 1-Inch vs 2-Inch vs 4-inch Furnace Filters: Which is Best? Inexpensive and energy-efficient. For instance, the most common cause of pressure drop is a dirty filter and some low-quality MERV 13 filters will clog more frequently, leading to increased pressure drop which requires more frequent filter replacements. These ratings lie on a scale of 1 to 20. In addition, poorly designed and installed duct systems already have external static pressures that are too high. Most of us dont have gauges to check the pressure drop, but we can remove the filter and hold it up to a light or a window. I normally see a product spec sheet with ASHRAE 52.2 testing, but I dont normally see Appendix J associated with it. (std. 99.97% of particles in the 0.3-micron range. The MERV scale ranges from 1 to 20, and on the lower end of the scale MERV 1 filtration can capture particles as small as 10 microns with 65% efficiency, and on the higher end of the scale MERV 20 filtrations can capture particles as small as 0.3 microns with 95% efficiency. This is your main concern. 3. 52.1-1992 ASHRAE Test Procedure ATMOSPHERIC DUST SPOT EFFICIENCY 1. HEPA, ULPA, and ASHRAE filters are typically used in commercial and industrial environments or in applications. While it is true that the more resistance to the flow of air results in a greater drop in air pressure on the other side of the filter, it isnt always true that higher MERV means higher pressure drop. MERV-15: Not a common filter efficiency, MERV-15 will sometimes be called a 95%+ filter as that was it's label under 52.1 This filter tends to get overlooked as it is between two very common high efficiency air filter values and although the static pressure is more comparable to 14 than 16, and the pricing is typically not too much more than 14, Similarly, the medium MERV filters also showed a decrease in airflow . "name": "What is the relationship between filter pressure drop and air flow rate? As dirt and debris gets trapped by the filter, there is less space for air to pass through, causing the pressure drop to rise throughout the filters life. The Velocity (speed) of the air flow is tested at 1 of 7 different speeds. The pressure drop for highly efficient filters like HEPA, ULPA, and ASHRAE tends to be higher, they use a quality filter media that is excellent at capturing pollutants and fine particles. "@type": "Question", ". The MEGApleat M9 filter is the longest-lasting and strongest MERV 9 pleated filter on the market. What Are All Those Gadgets On A Multitool? A thicker filter of the same MERV as a thinner one will usually have a larger face area, a lower resistance to air flow, and less pressure drop. Readers with specific questions should refer to the applicable standards or consult with an attorney. For reference, a typical dust particle is between .2 and 8 microns, while pollen starts at 7 microns and can get up to 70 microns in size. Hi Diane, MERV 20 are highly specialized filters and are not sold online. The pressure drop of a MERV 8 pleated air filter is around 0.12 inches of water, which is almost exactly the same as the 0.10 of the fiberglass. If the light is significantly blocked, install a new filter. The ASHRAE paper reviewed studies suggesting that: Use the MERVrating chart below to understand which filters are best for which applications. They will not hook up to your furnace or HVAC system. The Average arrestance is used to determine MERV 1 through 4. Arrestanceis a measure of the ability of an air filtration device to dust from the air. Rather, they use simplified words that everybody knows. Static pressure is the measurement of the exertion of air flow your HVAC system is moving throughout the system and ductwork. While these numbers are fairly close, at least in this example the filter with a MERV of 11, which is more than twice the MERV 5, had a lower resistance to air flow. This part is common to the three previous studies. A M rating of 13 through 16 are higher quality filters. This article is not a substitute for review of current applicable government regulations, industry standards, or other standards specific to your business and/or activities and should not be construed as legal advice or opinion. This is usually when the filter is new. Most manufacturers recommend ratings of 0.5 or lower for the IWC test. Bryan. These values were correct at the time of printing and Filtermakers do not accept any liability for any information provided herein. Get more great content like this sent to your inbox. 3. Before we look at the MERV rating chart (1-20 rating for 0.3 10 micron particles), lets answer this question: Do you know why HEPA filters are called HEPA? 1.0-3.0 greater than or equal to 90% These particles could hurt health and productivity. The final pressure drop/final resistance is measured when the filter has reached its total dust holding capacity and is ready to be replaced. In the most basic sense, the MERV rating gives us an idea of how well filters (air purifiers, furnaces) can filter out 0.3 to 10 micron (10-6m) particles. 3.0-10.0 greater than or equal to 70%, 1.0-3.0 greater than or equal to 50% Pressure Drop inches w.c. Our test duct is 8 feet long, two feet wide and two feet high. They are used in light industrial and residential applications. A 1 MERV 13 pleated filter has a pressure drop of around 0.27, and a 1 MERV 8 has a pressure drop of around 0.14. And MERV-13* is practically where you want to be. "@type": "FAQPage", Riga-Flo ", ASHRAE no longer recognizes MERV 17-20 values. Here's what you're not being told. of Energy). The filter can trap humidifier dust, lead dust, pet dander, and other small air pollutants. I know that filter may look pretty dirty, but the light . The MERV rating system goes from 1 to 16, with the higher numbers representing filters that can remove smaller particles from the air. The MERV rating is a measure of the ability of an air filter to remove particles from the air. This has resulted in confusion and apprehension on the part of the homeowner who wants to provide good quality indoor air, but not at the expense of that expensive HVAC system. This results in lower air pressure on the side of the filter from which the air exits. Need to know how to install your filters? The process is repeated 6 times. The Air Conditioning Contractors of America assumes that the pressure drop across a . ", Most of them will specify using a certain size filter, and they may also suggest a minimum MERV and a maximum MERV or IR (resistance to air flow of a new filter). Higher pressure drop = less airflow . Manufacturers are in continual competition to try to provide the best of both worlds in this area. However, if you are noticing that your air filter or smoke eater are not working as efficiently as it used to, or if you are constantly having to clean your air filters, it may be time to upgrade to a higher MERV rating. VOCs and odors are not covered by ASHRAE tests. This is one way a higher MERV filter can have a lower pressure drop than one with a lower MERV rating. The most prevalent MERV ratings are MERV 4, 6, 8, 10, 12, 14, and 16: MERV Rating In Air Purifier Specification Sheets (Or Lack There Of) A Higher MERV rating automatically means a better filter. 3.0-10.0 greater than or equal to 95%, 0.30-1.0 greater than or equal to 95% PickHVAC is also a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Can I purchase a 2x14x20 air filter with rating of 20, or 30 if possible, online? The higher the MERV rating the better the filter is at trapping specific types of particles. The chart displays the static pressure drop curves for filters at four MERV ratings. The scale rates how well a filter removes fine particulates from the incoming air. OK ! MERV ratings 1 to 4 are generally only used as pre-filters but can be found in many typical applications like commercial buildings, furnaces, and window AC units. Camfil makes the best filters on the market: they are the most energy-efficient, have a longer and more effective service life than other filters, and feature a lower pressure drop than competing brands. (Don't worry, we will have a full comparison chart at the end of this . Air filters with MERV ratings of 7 to 14+ can have pressure drops anywhere from 0.05 to 0.3 inch WC, depending on filter thickness and air flow velocity. }] Available in a variety of sizes for virtually any application. As a result, we cannot show you the price in catalog or the product page. The furnace filter frames use a M 10 rated level air filter. in the Inch-Pound system of measurement. ", The higher the filtering efficiency rating (MERV rating), the higher the pressure drop. "text": "As dirt and debris gets trapped by the filter, there is less space for air to pass through, causing the pressure drop to rise throughout the filters life. An air filter's minimum efficiency reporting value (MERV) rating measures how effectively the filter stops dust and other contaminants from passing through the filter and into the air stream. Just dont leave it out for more than a day, as we advise in our FAQ post, Can I Temporarily Run My Furnace Without a Filter. "name": "What are the signs of unhealthy static pressure in an HVAC system? Please click here to see any active alerts. Our Complete Recommended MERV Rating Guide is a good source for understanding the best filter for your HVAC system. He holds an HVAC associate degree from Lone Star College and EPA & R-410A Certifications. },{ ", In fact, some MERV 8 and MERV 9 filters have similar or higher pressure drops than the MERV 13 filters. "@type": "Question", Remembering to change your air filter is key to reducing the risk from pressure drop." In some ways they are better than all media filters in others they have drawbacks. What are they and why they matter? Filters rated MERV 7-12 are typically considered to be suitable for residential HVAC systems. 2. However, we use a pleated accordion style media, that allows us to effectively increase the filters surface area without having a high pressure drop or restricting air flow. The dirty MERV-8 filters had lower pressure drops than the clean MERV-13s. OurHEPA filtersystems are our best media air filters they remove 99.97% of all impurities. "@type": "Question", document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Copyright 2014-2023, PICKHVAC All Rights Reserved. These filters remove at least 99.97% of dust particle and are capable of removing viruses and radioactive material. Fiberglass and washable filters are typically 1-4 MERV, and can filter out particles of 10 microns and larger. Q: Can HVAC operations strategies help prevent the spread of COVID-19? High MERV ratings are recommended if you seek the removal of allergens from the air as the fibers they are comprised of are layered optimally to trap the smaller-size particles which are generally at fault for triggering symptoms in sensitive individuals. As an Amazon Associate we earn from qualifying purchases. WHEN YOU NEED THEM. } LakeAir Products are really made in the USA. Filters with higher MERVratings trap small particles more effectively than filters with lower MERVratings. Here is Ron Wilkinsons (P.E.) Remembering to change your air filter is key to reducing the risk from pressure drop. You can see from the MERV scale above that MERV 10 filter will filter out 85% of 3.0-10.0 m particles. Improved indoor air quality by capturing more particles, a higher MERV rating results in cleaner air being circulated throughout the home or office. LakeAir Commercial units have the ability to incorporate a MERV 14 High capacity media filter. The Chart below shows the scale used to evaluate each of the 6 test cycles. The test is based on particle size. However, an important factor is that MERV ratings are not standard and the quality of a filter will vary from one brand to the next, meaning that pressure drop will vary between different filters that are rated the same. ", The health benefits of particle filtration are proportional to "the reduction in total exposure to particles less than 2.5 m in diameter. This is an industry standard rating system. The chart also provides instructions on how to determine electric fan energy consumed by AHUs in your own facility. The MERV system rates air filters strictly on their ability to capture particles. An air filters pressure drop is the measurement of resistance to air that passes through the filter. From ASHRAE Journal Newsletter, December 8, 2020 . achieves MERV 8 rating before and after a conditioning step Independently tested and verified for quality control Support GridExtremely low pressure drop and high dust holding capacity Construction: For example, if bacteria ranges from 0.3 microns to 4 microns, the chart indicates a MERV 13 would be the minimum rating to select, and higher MERV-rated filters should be selected with the end users' level of comfort and Thickness of the filter. Tankless Water Heater Wire Size Calculator: What Gauge Wire (AWG)? filtration helps provide healthier indoor air quality, Learn more about these recommendations here, recommendations for filtration, humidity set points, automation and more. It holds 24X24 filters with a depth of up to 20. They are washable. Official websites use .gov The MERV rating is a scale from 1 to 16, with the higher numbers being the most efficient at removing particles. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommends a minimum MERV of 6 as their general rule for home HVAC systems. } This 4 inch filter has over 60 square feet of synthetic dirt grabbing fibers. The test begins with a clean filter. We may or may not be compensated for purchased you make as a result of our recommendation. Also, just because a filter fits with a system, that doesn't mean it's the best filter for the system. To build some good comparative data we tested 20 different air filters of various types, thicknesses and efficiencies. However, short of filter neglect, most modern HVAC systems are designed to be able to work with MERV filters in the range of 10 to 13. M 10 filters are easy on air blowers and fans. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease." Watch helpful videos from AFI. Particle filtration can be "modestly effective" against allergy and asthma symptoms. Cookies Policy. The chart below shows a detailed description for each MERV rating 1 through 16. "acceptedAnswer": { Do I Really Need to be Concerned with the MERV/Pressure Drop Issue? "name": "How does filter pressure drop affect flow rate? "@type": "Answer", This value is helpful in comparing the performance of different filters air). The rating system is called ASHRAE Standard 52.2-2007. This Standard is what led to the creation of the minimum efficiency reporting value, or MERV. Save my name, email, and website in this browser for the next time I comment. Minimum Efficiency Report Value (MERV) is a rating system designed by ASHRAE (American Society of Heating, Refrigeration, and Air Conditioning Engineers) to measure the effectiveness of air filters. They never need to be replaced. Pressure drop is defined by the National Air Filtration Association (NAFA):The pressure drop of a filter is a measure of its resistance to airflow through it.