A MERV 13 pleated air filter, the highest quality offering from Second Nature and most other filter companies, has a pressure drop of around 0.25. MERV values range from 1 (minimal filtering) to 20 (maximum filtering). . The filter is assigned a value based on the test. Pressure drop occurs, airflow is reduced and system . "name": "What is static pressure? The resulting rating is theen given to each filter. MERV stands for "Minimum Efficiency Reporting Value" and is a system used to determine how efficiently an air filter can clean the air in your home with each use. It can remove small particles such as dust mites, spray paint dust, carpet fibers, and pollen. Get more great content like this sent to your inbox. 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). There are many benefits to having a higher MERV rating, including: If you have a high MERV rating, you should change your filter every 3 months. But what is MERVrating, exactly? The accepted pressure drop is different for each air conditioning or air handling system, and you should always refer to your manufacturers guide prior to inserting replacing your air filter to ensure you are using the appropriate filter. You can see from the MERV scale above that MERV 10 filter will filter out 85% of 3.0-10.0 m particles. Here's what you're not being told. Filters with higher MERV ratings are more restrictive because they are capable of filtering more particles than filters with lower MERV ratings. 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. When choosing a filter, remember that airflow (pressure drop) is just as important to consider as filtration (MERV rating). The MEGApleat M9 filter is the longest-lasting and strongest MERV 9 pleated filter on the market. 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). 2/11/20 },{ 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. Cookies Policy. These filters are used primarily to protect equipment. Our test duct is 8 feet long, two feet wide and two feet high. } Can you provide some insight on how ASHRAE 52.2 Appendix J plays a role in the data tables mentioned above? 3.0-10.0 greater than or equal to 70%, 1.0-3.0 greater than or equal to 50% "name": "What are the signs of unhealthy static pressure in an HVAC system? Our filtration specialists can help you determine the right air filter strategy for your facility. For comparison, a grain of sand is about 60 microns. "text": "Noisy systems when running, high static pressure could be the culprit. Thickness of the filter. Will it burn up your HVAC system? 3M Pro Series Residential Air Cleaning Filters 4" and 5" filters last up to 6 to 12 months. All air cleaners require periodic cleaning and filter replacement to function properly. 14 Culprits To Check For Now, MMBTU To MMSCFD Calculator For Natural Gas + Chart, 8 Best Infrared Heaters For Indoors, Patios, Garages (With ECO Thermostats), AGM Battery Voltage Charts: 12V, 24V Deep Cycle Battery Voltage, Lead-Acid Battery Voltage Chart For 6V, 12V, 24V, 48V Batteries, Natural Gas MMSCFD To MMBTU/Day Calculator + Chart, Smoke, dust, oil smell, bacteria, sneeze droplets, Car emissions, bigger dust particles (lead), Legionella, Hair spray, mold spored, mite debris, fabric protector, cat, and dog dander, Pollen, sanding dust, cockroach debris, textile fibers, 85% for 3.0-10.0 m particles, or greater, 90% for 3.0-10.0 m particles, or greater. [CDATA[ A numerical chart with values from one through 20 from 1 to 20 measures how effectively the filter stops dust and other contaminants from merv merv rated merv rating merv ratings merv stands minimum efficiency reporting value microparticle performance rating mpr minimum efficiency reporting value mpr mpr ratings range from 1 20 rated rating ratings signify an air filter's effectiveness at reducing airborne particles and contaminants standard 52 5 minimum the minimum efficiency reporting value. This allows greater airflow without having to increase the size of the actual filter. At LakeAir, we recommendMERV 10 filtersas our good air filter. The FPR system goes a step further and also rates filters based on the amount of pressure drop they introduce and their dust holding capacity. This also means that as the MERV rating goes up, the more particles and contaminants the filter can capture. The majority of residential HVAC systems use a 1 thick filter, but filters are available at 2, 4 and 5 thick. commentary on the MERV scale when it first came to light in 1987: (MERV rating) represents a quantum leap in the precision and accuracy of air purifiers. Resistance is measured in inches water gauge (w.g.) These are the 4 average contaminant size intervals MERV rating applies to: These are just a few contaminants that we want to get rid of with a good MERV air purifier. },{ 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. Includes a moisture resistant, high wet-strength beverage board frame. This is usually when the filter is new. 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. 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. The chart displays the static pressure drop curves for filters at four MERV ratings. This one of the main reasons why it is so important to check, change, and clean your air filter every month to help ensure your air filters pressure drop does not get too high and cause strain on your air conditioner/handler. "@type": "Answer", The filter has a Galvanized steel frame, the filter dimensions are 20 x 19.75 x 3.75. It is measured in Pascals in the SI system. 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. These ratings lie on a scale of 1 to 20. Below is a chart comparing the pressure drop of standard 20X24X1 MERV8, 11, and 13 at 1000 CFM. } The test results are then used to give a filter its MERV rating. 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. Filters use various types of medias depending on the application or what the environment requires. Some pleated filters with the same or lesser MERV's have higher pressure drops. Get Started With a New Filtration Strategy. Here is a list of the best air purifiers; the best ones have to have filters with as high MERV rating as possible. Since it collects more particles, its likely to get dirty more quickly than some other filters. However, most HVAC systems built in the last 20 years should have no issue using a MERV 6 - MERV 13 rated air filter. Thats why air filter producers dont usually specify the MERV rating. HEPA is a type of pleated mechanical air filter. Average Particle Size Efficiency in Microns, 1.0-3.0 greater than or equal to 20% The MERV rating system goes from 1 to 16, with the higher numbers representing filters that can remove smaller particles from the air. A MERV rating is a numerical rating system developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to rate the effectiveness of air filters. "text": "The higher the MERV rating the more efficient the filter is at filtering out and capturing air particles and contaminants. 3M Filtrete MERV 5 Review Conclusion. This one of the main reasons why it is so important to check, change, and clean your air filter every month to help ensure your air filters pressure drop does not get too high and cause strain on your air conditioner/handler. Simple use of MERV rating chart for air purifier filters: The higher the MERV rating, the better the filter. 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. LakeAir provides discounts to Veterans, First Responders, and the Elderly. NEC 310.16 Table: Copper And Aluminum Wire Ampacity Chart, NEC 310.12 Table: Wire Sizes For 100-400 Amp Services (83% Rule), kWh To Therms Calculator + Conversion Chart (1 kWh = 0.03412 Therms), MMBTU To Therms Calculator + Chart (1 MMBTU = 10 Therms), Therms To MMBTU Calculator + Chart (1 Therm = 1/10 MMBTU), AWG To Circular Mils Chart (For 4/0 AWG To 20 AWG). Air Purifiers, Dehumidifiers and Treatment. With finer filtration, fewer airborne contaminates & dust particles are allowed to pass through the filter. the expression of the Minimum Efficiency Reporting Value (MERV). These filters should not be used in home HVAC or furnace systems. },{ Thanks for any clarity. in the Inch-Pound system of measurement. Not as taxing on your HVAC system. Weigh the test filter. MERV stands for Minimum Efficiency Reporting Value. Spun fiberglass almost always has a lower IR than other materials. The lower the pressure drop the easier it is for air to flow through the filter. If your facility needs to upgrade to MERV 13+, R.P. The dirty MERV-8 filters had lower pressure drops than the clean MERV-13s. As a result, we cannot show you the price in catalog or the product page. These values were correct at the time of printing and Filtermakers do not accept any liability for any information provided herein. The chart below shows a detailed description for each MERV rating 1 through 16. The amount of the HVACs air flow slowed by the filter is equivalent to the filters pressure drop. 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. The test duct fans can operate up to a speed of 750 fpm. "@type": "Question", This rating system reports how well the filter captures and holds dust. This guideline determines a filters performance by particle size. There is still a common misconception that having a high MERV rated filter will be too restrictive and strain your unit. ASHRAE stands for the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Do I Really Need to be Concerned with the MERV/Pressure Drop Issue? They used a 20 x 20 filter. Since MERV 13 filters (https://www.rpfedder.com/filtration/merv-13-filters/) are on the higher end of the rating scale, they can be susceptible to excessive pressure drop. Generally, filters with higher MERV ratings have less airflow. WHEN YOU NEED THEM. This value is helpful in comparing the performance of different filters, The rating is derived from a test method developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) [see. 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. The pressure drop across an air filter will determine how negatively the filter affects airflow. Fibrous Filter Media,Philip J. A position paper published by ASHRAE looked at the claim that particle filtration has health benefits. The performance is based on particles that are 0.3-10 micron in diameter. Hot or cold spots throughout your home? } } We are hiring! This level of filtration does fall into the MERV system but they are shown here to add continuity to the overall filter picture. The filters initial pressure drop (initial resistance) will vary by the filter type, MERV rating, and size. This is one way a higher MERV filter can have a lower pressure drop than one with a lower MERV rating. You can check the best medical-grade air purifiers here; these use H13 HEPA filters. This system is designed by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). The informed consumer is a powerful force in the marketplace. A flat design with a MERV 13 would be too restrictive. The furnace filter frames use a M 10 rated level air filter. "name": "Does air filter pressure drop change? 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. Typically, the higher the MERV rating, the higher the pressure drop and the more restrictive the air flow is. 6-Pack 24x24x4 XTREME PLUS Air Filters MERV 8 XPH-STD4-405- 24X24X4 - $45 (Pacolet) 24x24x4 Air Filter for HVAC. "text": "An air filters pressure drop is the measurement of resistance to air that passes through the filter. They may negatively affect certain HVAC systems. 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). As the MERV rating increases the finer the filtration becomes. The MERV rating is a measure of the ability of an air filter to remove particles from the air. Similarly, the medium MERV filters also showed a decrease in airflow . So many data center operators are adjusting filtration protocols, including upgrading to finer MERV (minimum efficiency reporting value) 13 filters, to better filter out aerosols and COVID-19 virus carriers.1 But there is no free lunch. Air conditioning air ducts air filter air filters air filtration air purifier air purifiers air quality airborne particles airfilters airflow asthma dust filter filters filtration filtration and disinfection filtrete flu heating and air conditioning hepa filter hepa filters history of merv indoor air quality made in the usa merv microparticle performance rating. Minimum Efficiency Reporting Values, or MERVs, report a filter's ability to capture larger particles between 0.3 and 10 microns (m). While it is not important to fully understand the comparison chart, it is good to familiarize yourself with it. The filter can trap humidifier dust, lead dust, pet dander, and other small air pollutants. The higher the pressure drop the more restrictive the filter is to air flow. The higher the MERV, the smaller the particles removed, and the more of them removed. Hi Diane, MERV 20 are highly specialized filters and are not sold online. Many pleated HVAC air filters can still have a high MERV rating, while not drastically restricting air flow. The scale rates how well a filter removes fine particulates from the incoming air. "acceptedAnswer": { It is measured in Pascals in the SI system." The higher the MERV number, the smaller the particles the filter can trap and the more of them. Filter Rating: MERV 8-10 | FPR 5| MPR 600.MERV 8 air flow & pressure drop Sold in Packs of 624x24x4 MERV 8 furnace A/C filters are made with electrostatically charged synthetic media. Rather, they use simplified words that everybody knows. (1000-3000+ Sq Ft Homes), Thermostat Says Heat On But No Heat? As an air filter manufacturer, we are uniquely positioned to custom make any and all types of air filters. Pre filters are rated MERV 2. MERV ratings are derived from the ASHRAE 52.2-2012 test which groups the particles sizes into three categories. In fact, some MERV 8 and MERV 9 filters have similar or higher pressure drops than the MERV 13 filters. HEPA, ULPA, and ASHRAE filters are typically used in commercial and industrial environments or in applications. 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. What are the benefits of a higher MERV rating? "acceptedAnswer": { The performance ratings given above are adapted from equivalent EU and MERV ratings and test classifications for filters as outlined in AS1324.1, EN779 and ASHRAE52. Once the filter is fully loaded the filter will reach its final pressure drop. However, one study found that actual pressure drops in home. The US Department of Energy recommends at least a MERV 8. The Maxum electrostatic is a great air purifier for your home. Each filter is assigned a rating based on how much debris a filter manages to block when circulating air. According to this paper, there's a well established connection between higher concentrations of particles in outdoor air and poor health outcomes, so it would make sense that filtering these particles out of indoor air could lead to better health outcomes. 99.97% of particles in the 0.3-micron range. SIGN UP FOR EMAILGet more great content in your inbox. The higher the number, the better the filter is at capturing larger particles between 0.3 and 10 microns (m). That's all. These filters are installed in two air handling units (AHUs) in the Delaware Biotechnology Institute. The smaller pores in more highly rated air filters create resistance to air flow, and if the filter is used in an HVAC system that is not designed to handle this resistance, it can lower the system's efficiency, decrease indoor air quality, and put strain on the system's fan. If the light is significantly blocked, install a new filter. When youre buying an air purifier for a specific purpose, you need to know how big the air contaminants youre looking to remove are. HEPA and ULPA filters are represented in the 17 through 20 ratings. "@type": "Answer", Two 14X14 filter grilles are way too small. Performance MERV 8 Air Filter MERV 11 Air Fir Filter Particle Size 3.0 - 10.0 microns 1.0 - 3.0 microns % Particles Captured 90% 95% Lasting Time 3 months 2 - 3 months Level of Usese Basic - Standard The primary concern that some people have with the pressure drop issue is that of wondering if they are going to damage their HVAC system by using a filter with a high MERV. The poorest performance is used. 3. Because they go off the MERV chart, they are referred to as HEPA filters or high-efficiency filters. Enter your info to get the catalog emailed to you! The rating system is called ASHRAE Standard 52.2-2007. A filter is sent to an ASHRAE lab, and its efficiency is tested against aerosols at three different size ranges (E1, E2, and E3). Calculator + Chart (Natural Gas), Average Gas Bill For 1-Bedroom Apartment: State-By-State Cost Analysis, Average Electricity Bill For 4 Person Household (Survey Analysis), How Many kWh Per Day Is Normal? Grainger Editorial Staff. 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 . The higher the filtering efficiency rating (MERV rating), the higher the pressure drop. 52.1-1992 ASHRAE Test Procedure ATMOSPHERIC DUST SPOT EFFICIENCY 1. These filters remove at least 99.97% of dust particle and are capable of removing viruses and radioactive material. Most current home HVAC units can accommodate a filter with a MERV 13 or lower. Additionally, some brands drop their MERV rating almost immediately upon first use (e.g., a so-called MERV-13 becomes a MERV-9 as its used it cant hold its efficiency). It is not recommended to continue to use your filter beyond its final pressure drop point. What are 'Dark Factories,' and Do They Really Exist? ", The health benefits of particle filtration are proportional to "the reduction in total exposure to particles less than 2.5 m in diameter. Pleats look like an accordion, and can more than double the face area of a filter. This could be because your system is moving too much or not enough air through its ductwork. Tankless Water Heater Wire Size Calculator: What Gauge Wire (AWG)? Is it a problem? So, you just purchased some new filters for your home HVAC system. The MERV 5 is an excellent entry into the pleated filter lineup because it is low cost, readily available, and will . These particles are 1-3 microns. I normally see a product spec sheet with ASHRAE 52.2 testing, but I dont normally see Appendix J associated with it. The higher the MERV rating, the more a filter can capture and the cleaner the air will be. We may or may not be compensated for purchased you make as a result of our recommendation. { "acceptedAnswer": { For example, a household pleated filter that uses synthetic media will have a lower pressure drop than a micro-fiberglass media that is used in critical environments such as a hospitals and datacenters." Average particle size efficiency for 1 size range (0.3-1.0 micron, to be exact). MERV rating. "acceptedAnswer": { (std. Save my name, email, and website in this browser for the next time I comment. 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. LakeAir replacement filters use 4 different MERV rated filters. This value is used at the filters lowest efficiency. Which is not recommended, and could cause increased energy bills, and undue wear on your HVAC unit. The lower air pressure will then cause wasted energy because the HVAC system will need to spend more time and power to heat or cool the building to the desired temperature. That will definitely increase the pressure drop and place unwanted strain on your HVAC system. Firstly, MERV ratings range between a 1 and 20 scale, which denotes the effectiveness and efficiency of filters to catch specific air-particle sizes. I know that filter may look pretty dirty, but the light . When your HVAC system is running the filter slows and limits the air that is being pulled through your vents and ducts. What was their secret? Improved indoor air quality by capturing more particles, a higher MERV rating results in cleaner air being circulated throughout the home or office. 2. Fiberglass and washable filters are typically 1-4 MERV, and can filter out particles of 10 microns and larger. MERV10, MERV 13, and MERV16) Pressure Drop Chart Static Pressures at variable CFM (in W.C.) Filter Number = 410 (MERV10), 413 (MERV 13), 416 (MERV16) CFM 400 = .03, .05, .07 CFM 800 = .07, .10, .13 Air filter selection chart and Performance Ratings. The range is from 1 (lowest efficiency) to 20 (highest efficiency). Leadership in Energy and Environmental Design (LEED) also recommends a minimum of MERV 8. M 10 filters are easy on air blowers and fans. A lint trap in a dryer is about M 2. JavaScript seems to be disabled in your browser. You must have JavaScript enabled in your browser to utilize the functionality of this website. Does EPA certify/register or provide lists of acceptable air cleaners or manufacturers/sellers? },{ was at various amounts of airflow in cubic feet per minute (CFM). The truth is, there are many differences between HVAC filters that make statements like these tantamount to comparing apples with oranges they are both fruits, but thats where the similarities end. The final pressure drop/final resistance is measured when the filter has reached its total dust holding capacity and is ready to be replaced. Efficiency is measured by the percentage of particles captured. 1-Inch vs 2-Inch vs 4-inch Furnace Filters: Which is Best? These are the smallest particles that both FPR and MERV-rated air filters will be able to pick up. "@type": "Question", The Air Conditioning Contractors of America assumes that the pressure drop across a . When selecting the right filter for your application, higher is not always better. ", Q: Can HVAC operations strategies help prevent the spread of COVID-19? 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. "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. 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. MERV rating ranges between 10 and 12 are suitable for removing a broad range of particles. Hi, great article! filtration helps provide healthier indoor air quality, Learn more about these recommendations here, recommendations for filtration, humidity set points, automation and more. A MERV rating chart shows a numerical value. ASHRAEdeveloped the MERV air filter efficiency rating system. Using an air filter with a MERV rating that is too high is as bad as using one that is too low. We recommendMERV 11 filtersas our better air filter. 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. MERV 12 filter, for comparison, will filter out 90% of the same particles. It also shows air filter efficiency levels. Actual Size: 23-3/8 x 23-3/8 x 3-3/4. The information contained in this article is intended for general information purposes only and is based on information available as of the initial date of publication. Filters down to 10.0 micron particle size, Filters down to 3.010.0 micron particle size, Filters down to 1.03.0 micron particle size, Filters down to 0.31.0 micron particle size, Filters down to less than 0.30 micron particle size. Other Signs your MERV is Too High / Your Filter Too Restrictive, Can I Temporarily Run My Furnace Without a Filter, Relationship Between Pressure Drop and MERV Rating, Do Not Use High MERV (12+) Filter for HVAC. A filter with a MERV rating of between 1-6 can remove particles anywhere between 0.3 to 10 microns with an effectiveness of 20%. Airflow through the vents is lower: Is the new filter causing low airflow? To get the right HVAC product and suitable MERV-rated air filter, you should know the area you want to use. A filters material type and efficiency rating affect the pressure drop and resistance to air flow. "acceptedAnswer": { Even filters sharing the same MERV rating may have differing pressure drops. "text": "When you air filter is installed, it is a barrier between your HVAC and your ducts/vents. VOCs and odors are not covered by ASHRAE tests. Commercial Buildings. No representation is made that the information or references are complete or remain current. "name": "Does the material affect the pressure drop of the filter? What MERV filter is recommended for preventing the transmission of airborne illnesses such as COVID-19? The higher the MERV rating, the more particles the filter will remove. Remembering to change your air filter is key to reducing the risk from pressure drop." Need more details? OurHEPA filtersystems are our best media air filters they remove 99.97% of all impurities. Using the worst case particle size results in the worst case efficiency rating (i.e. When used in a multi-filter system, the pre-filters trap the dirt and large particles before the air reaches the final filters downstream, which then remove the smaller particles. When used as final filters, they are the primary filters for an HVAC system. E2 arrestance is for the middle size particles. ", It was about 0.08 inches of water column (20.7 Pascals). }] Typical Applications. Other materials used for filters have different MERV and air flow (IR) properties. Levels 17 and above are used . "@type": "Question", Dust spot efficiency is a soiling index that ", The MERV system rates air filters strictly on their ability to capture particles. At the lower end of the efficiency spectrum a fiberglass or polyester panel filter may have a MERV of 4 or 5. "@type": "Answer", 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. The High Capacity MERV 14 Media filter (HC-14) provides a large volume of dust capacity. ; This scale addresses particles that scope in size from 0.3 to 10 micrometers. Air Filters, Inc. is committed to providing a "one-stop shop" for all of your air filtration requirements. They are usually reserved for superior commercial applications. (State-By-State Chart), How To Convert Therms To kWh? Thick and high-MERV filters can cause a significant drop in pressure inside your HVAC system from before to after the filter. 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. What is interesting is that youll rarely see MERV rating in an air purifier specification sheet. "@type": "Question", 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. Its and apples and oranges kind of thing. Browse a full list of industry terms to better choose your filters. As air moves through a buildings HVAC system, air filters trap and collect large and small particles such as dust, allergens and microorganisms. 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. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease." Where to find MERV and IR: This information is printed on the edge of the frame of the filter and can be seen before you purchase it. P.S. The more tightly woven or thick a filters media is, the more particles and contaminates the filter can trap." The MERV rating is a scale from 1 to 16, with the higher numbers being the most efficient at removing particles.