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. The Minimum Efficiency Reporting Value (MERV) of an air filter (from 1 to 20) measures how much dust, pollen, mold spores, and other contaminants pass through that filter to enter the indoor airstream. . MERV rating ranges between 10 and 12 are suitable for removing a broad range of particles. 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? When your HVAC system is running the filter slows and limits the air that is being pulled through your vents and ducts. Also, just because a filter fits with a system, that doesn't mean it's the best filter for the system. { This chart shows their stated resistance to air flow in inches of water column (IWC/i.w.c.) Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings. This 4 inch filter has over 60 square feet of synthetic dirt grabbing fibers. Estimated energy savings from 5-Star filters per AHU, extrapolated to annual basis (assuming 24/7 AHU operation, 34,235 cfm airflow per AHU): ($0.463/cfm $0.575/cfm) x 34,235 cfm = $3,834 annual electric energy savings per AHU. Since it collects more particles, its likely to get dirty more quickly than some other filters. This part is common to the three previous studies. Besides the basic need for good indoor air quality (IAQ), many extremely relevant reasons exist in 2020 to discuss air filters, according to Kathleen Owen, Fellow ASHRAE, member of the ASHRAE Epidemic Task Force, and Carolyn (Gemma) Kerr, Ph.D., Life Member ASHRAE. Official websites use .gov ", Characteristics. Using an air filter with a MERVrating higher than what your furnace or air conditioner manufacturer recommends can actually impair its performance. 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 is important to consider when choosing a filter for your application and your HVAC unit. For a product to be called Made in USA, the product must be all or virtually all made in the U.S. How to Tell if I Should Change Furnace Filter. These values were correct at the time of printing and Filtermakers do not accept any liability for any information provided herein. 1-Inch vs 2-Inch vs 4-inch Furnace Filters: Which is Best? in the Inch-Pound system of measurement. Most current home HVAC units can accommodate a filter with a MERV 13 or lower. "acceptedAnswer": { You can check the whole EPAs list of air pollutants here. A MERV rating chart shows a numerical value. These filters can cause restricted airflow. MERV stands for Minimum Efficiency Reporting Value. The blowers in HVAC units rely on a good air supply to keep them cool. This value is used at the filters lowest efficiency. This is an industry standard rating system. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease. 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. 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. Activated carbon filtersremove VOCs and odors. 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. ", Other materials used for filters have different MERV and air flow (IR) properties. Static pressure is the measurement of the exertion of air flow your HVAC system is moving throughout the system and ductwork. 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. ", He holds an HVAC associate degree from Lone Star College and EPA & R-410A Certifications. What are ionizers and other ozone generating air cleaners? Do a quick search online using MERV in your question and youll see statements such as, Higher MERV means higher pressure drop. OR Higher MERV filters can destroy your HVAC system. These statements are presented as set-in-stone, hard facts that are not to be refuted. The pressure drop across the MERV-13 filter was 0.0274 inch of water column. As the MERV rating increases the finer the filtration becomes. 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. "acceptedAnswer": { I know you're dying of the suspense now, so here are all the measurements. } In some ways they are better than all media filters in others they have drawbacks. 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. 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. What MERV filter is recommended for preventing the transmission of airborne illnesses such as COVID-19? The majority of residential HVAC systems use a 1 thick filter, but filters are available at 2, 4 and 5 thick. This value is helpful in comparing the performance of different filters It was about 0.08 inches of water column (20.7 Pascals). Rather, they use simplified words that everybody knows. They are washable. Thats why air filter producers dont usually specify the MERV rating. These ratings lie on a scale of 1 to 20. Using an air filter with a MERV rating that is too high is as bad as using one that is too low. They generally allow enough air to flow through a furnace filter to allow the blower to stay cool. ; High-rated media is able to retain fumes . Refer below to four average contaminant size intervals for MERV rating consideration. "acceptedAnswer": { Pleats look like an accordion, and can more than double the face area of a filter. It assigns a single number to a filter in an effort to identify its minimum performance in removing particulate from an airstream. "text": "The pressure drop of a filter is a measure of its resistance to airflow through it. How do I know if I need a higher MERV rating? Doing so could cause strain on your HVAC unit and could cause costly maintenance and repairs. Pressure Drop inches w.c. "@type": "Answer", 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. The Back pressure from this filter is 0.22 WG. "@type": "Question", While it is not important to fully understand the comparison chart, it is good to familiarize yourself with it. The 3M Filtrete MERV 5 review concluded that this furnace filter is a good choice for any household as long as there are no allergy issues, pets such as dogs and cats, smokers in the house. If you have more questions about the right air filter or air purifier, call our customer service number 800-558-9436. Pollutant Size. MERV stands for Minimum Efficiency Reporting Value. 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. "@type": "Question", The higher the MERV rating, the more a filter can capture and the cleaner the air will be. should be helpful in determining the MERV rating of the filter once the particulate size has been determined. These air filters are used to protect people or products from airborne contaminants. The higher the MERV of a filter, the smaller and the more particles it will remove from the air that passes through it. Again, it has a pleated design. 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. MERV Rating:MERV is the Minimum Efficiency Reporting Value - The gist of MERV is a measurement of the smallest (minimum) particles a filter will effectively (efficiency) remove when tested - with test results that are verifiable and reportable (reporting value). Our filtration specialists can help you determine the right air filter strategy for your facility. An official website of the United States government. The range is from 1 (lowest efficiency) to 20 (highest efficiency). 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. Low initial resistance and high dust holding capacity requires less energy consumption, resulting in lower operating costs and energy savings. Weigh the test filter. The amount of the HVACs air flow slowed by the filter is equivalent to the filters pressure drop. When a particle is in the 0.3 to 1 micron in size it is considered microparticle. } On the other hand, a merv 13 filter can sift all the particles that a. It is an acronym for "high efficiency particulate air [filter]" (as officially defined by the U.S. Dept. The chart below shows the MERV ratings. While it is true that the more the air filter traps the more effective it is at capturing more particles; it will eventually become too loaded, at which point, the airflow could be zero and extremely restrictive. We will help you understand your best air filtration options. When used as final filters, they are the primary filters for an HVAC system. Typical MERV 11 Filter 3M MERV-11 3M MERV-14 How Our Filters Perform Over Time This chart shows how our media performs over time as a 20" x 25" filter collects particulates as measured at different air volumes. Readers with specific questions should refer to the applicable standards or consult with an attorney. Welding fumes and milled flour are this size. Does the airflow significantly improve? This level of filtration does fall into the MERV system but they are shown here to add continuity to the overall filter picture. 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? The final pressure drop/final resistance is measured when the filter has reached its total dust holding capacity and is ready to be replaced. 3. The poorest performance of the filter on all three particles sizes during each of the 6 cycles is used to determine the filters MERV rating. "acceptedAnswer": { Below is a chart comparing the pressure drop of standard 20X24X1 MERV8, 11, and 13 at 1000 CFM. WHEN YOU NEED THEM. The MERV is a single number that is used, along with the air velocity at which the test was performed, 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. "acceptedAnswer": { Products and solutions to help your business move forward. "name": "What is the relationship between filter pressure drop and air flow rate? You must have JavaScript enabled in your browser to utilize the functionality of this website. 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. That will definitely increase the pressure drop and place unwanted strain on your HVAC system. They are available for the home and business. You can see from the MERV scale above that MERV 10 filter will filter out 85% of 3.0-10.0 m particles. Standard 52.2 establishes a testing protocol. Firstly, MERV ratings range between a 1 and 20 scale, which denotes the effectiveness and efficiency of filters to catch specific air-particle sizes. "@type": "Question", They may negatively affect certain HVAC systems. SIGN UP FOR EMAILGet more great content in your inbox. Some pleated filters with the same or lesser MERV's have higher pressure drops. Your HVAC equipment will give off a few clues that the filter is too restrictive and creating unacceptable pressure drop. The mid-MERV is twice as much and the high-MERV is three times as much. These include mold, smoke and pollen. Changing your air filters regularly will prevent filters from being loaded and overly restrictive. 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 rating was devised by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to answer one question: Which air purifier is the most effective? In other words: HEPA filters are better than anything MERV rating can measure. It is quite an important filter-specific factor. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. "name": "What are the signs of unhealthy static pressure in an HVAC system? 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? ASHRAE stands for the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Hot or cold spots throughout your home? 3.0-10.0 greater than or equal to 95%. This results in lower air pressure on the side of the filter from which the air exits. The furnace filter removes at least 90% of solid pollutants that measure 3.0 to 10 microns in diameter. 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 . Generally, increasing filter efficiency leads to increased pressure drop which can lead to reduced air flow through the HVAC system, more . Need more details? The E3 arrestance describes how well an air filter removes larger particles such as dirt, lint, hair, and dust. Hot or cold spots throughout your home? For facility managers this has provided a variety of challenges, including considerations around increased pressure drop in HVAC systems due to the more restrictive nature of filters with higher MERV ratings. air), Latent Heat (BTU/hr) = 0.69 x CFM x gr. in the Inch-Pound system of measurement. Air Purifiers, Dehumidifiers and Treatment. It is a rating system incorporated into the test specification of ASHRAE 52.2. Guaranteed against media pack failure to 5.0 w.g. Using the worst case particle size results in the worst case efficiency rating (i.e. 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? Has the lowest pressure drop of any fine fiber 4 deep mini-pleated filter. The lower the pressure drop the easier it is for air to flow through the filter. Check your filter at least once a month for dust buildup. Air filters can be used as final filters or pre-filters. The range is from 1 (lowest efficiency) to 20 (highest efficiency). 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. Cookies Policy. Share sensitive information only on official, secure websites. MERV stands for Minimum Efficiency Reporting Value. The filters initial pressure drop (initial resistance) will vary by the filter type, MERV rating, and size. 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. Building technology group ASHRAE has compiled recommendations for filtration, humidity set points, automation and more. "name": "What is static pressure? We may or may not be compensated for purchased you make as a result of our recommendation. PICKHVAC Terms of Use: Some of the products seen on our site are delivered through a relationship with outside suppliers like Networx.com, Google, and others. Spun fiberglass almost always has a lower IR than other materials. The poorest performance is used. How often should I change my filter if I have a high MERV rating? These dust particles fall into three size groups. Merv-ratings But before you update the filter, make sure it's specific. A: Although ASHRAE does not recommend a specific MERV filter rating for preventing COVID-19 transmission, the organization suggests that upgrading systems in non-healthcare facilities to MERV-13 or the highest achievable level can be a worthwhile step in emergency response plans. Surface area of the filter. 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 rating system is called ASHRAE Standard 52.2-2007. "acceptedAnswer": { Frequent filter changeouts will help minimize risks from pressure drop. 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." "@type": "Answer", They never need to be replaced. Is it a problem? 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 chart also provides instructions on how to determine electric fan energy consumed by AHUs in your own facility. 3. "@type": "Answer", Yes, really! Once the filter is fully loaded the filter will reach its final pressure drop. Green Manufacturing ~ How green is your air purifier? This is how they get the name MERV (MINIMUM Efficiency Rating Value). It also shows air filter efficiency levels. ". 52.1-1992 ASHRAE Test Procedure ATMOSPHERIC DUST SPOT EFFICIENCY 1. 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. "@type": "Answer", The speed at which the test was done is noted in the test results. "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. Use this rating system compare filters made by different manufacturers. MERV Rating Chart: How to Choose the Right Air Filter for You? 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. What if they cause too much pressure drop? This helps improve indoor air quality and prevents the build up of contaminants in equipment and damaging it. While its helpful to know something about the relationship between MERV and pressure drop, it isnt generally something that you should lose any sleep over. "acceptedAnswer": { ), CO2 Heat Pump Water Heaters Vs. Resistive Hot Water Heaters, MERV 13 Filter Pressure Drop: Guidance for Facility Managers, Free Tool to Measure the Air Changes Per Hour of Your Space, Mitigating the Impact of COVID-19 on Small Businesses By Improving Indoor Air, The In-Depth Guide to HEPA Filters in Hospitals, Medical Offices, & Clinics, Reopen Safely and In Compliance with NYS Mandates, Measure Your Spaces Air Changes Per Hour, https://www.rpfedder.com/filtration/merv-13-filters/. The majority of residential HVAC systems use a 1" thick filter, but filters are available at 2", 4" and 5" thick. 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. 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. },{ Actual Size: 23-3/8 x 23-3/8 x 3-3/4. A lint trap in a dryer is about M 2. Here is a list of the best air purifiers; the best ones have to have filters with as high MERV rating as possible. Get more great content like this sent to your inbox. Each air filter has its own unique pressure drop. I normally see a product spec sheet with ASHRAE 52.2 testing, but I dont normally see Appendix J associated with it. Doing so could cause strain on your HVAC unit and could cause costly maintenance and repairs." 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. Two 14X14 filter grilles are way too small. The MERV 5 is an excellent entry into the pleated filter lineup because it is low cost, readily available, and will . Heres why: Reputable HVAC manufacturers like Carrier, Rheem and Lennox make their systems to high standards that allow a certain amount of leeway in the choice of filters. } If your facility needs to upgrade to MERV 13+, R.P. The higher the number, the better the filter is at capturing larger particles between 0.3 and 10 microns (m). DC Wire Gauge Calculator: What Gauge Wire (12V, 24V, 48V)? MERV 9 through 12 filters are good filters for general home use. Average Particle Size Efficiency in Microns, 1.0-3.0 greater than or equal to 20% FPR 10 is the same as MERV Ratings 13; MPR vs. MERV Air Filter Ratings. Typically, the higher the MERV rating, the higher the pressure drop and the more restrictive the air flow is. ASHRAEdeveloped the MERV air filter efficiency rating system. Pressure drop describes what happens when air pressure is decreased from one section in an HVAC system to another section downstream. 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. The most prevalent MERV ratings are MERV 4, 6, 8, 10, 12, 14, and 16: A Higher MERV rating automatically means a better filter. That will result in more resistance to air passing through it. The higher the MERV rating, the more particles the filter will remove. },{ There is still a common misconception that having a high MERV rated filter will be too restrictive and strain your unit. Rooms will be too hot or too cold: This is a symptom of low airflow. 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. 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. Q&A Debunking Myths About MERV, Air Filtration . How to Mitigate Pressure Drop Caused by MERV 13 Filters According to theAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),this filtration helps provide healthier indoor air quality. Because they go off the MERV chart, they are referred to as HEPA filters or high-efficiency filters. The higher the filtering efficiency rating (MERV rating), the higher the pressure drop. The manometer below shows my reading across one of the clean MERV-13 filters. There seems to be a lot of misunderstanding about the MERV rating of HVAC air filters and its effect on the pressure drop within the system. VOCs and odors are not covered by ASHRAE tests. Many pleated HVAC air filters can still have a high MERV rating, while not drastically restricting air flow. Frankly, that can happen with about any filter higher than a MERV 5 if it gets dirty and clogged. It isnt easy to navigate through 20 classes of MERV ratings. } ", Not as taxing on your HVAC system. And MERV-13* is practically where you want to be. "text": "An air filters pressure drop is the measurement of resistance to air that passes through the filter. "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. Can I purchase a 2x14x20 air filter with rating of 20, or 30 if possible, online? Filters rated MERV 7-12 are typically considered to be suitable for residential HVAC systems. During each cycle a predetermined amount of dust particles is released into the airstream. 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. They remove pet dander and most allergy causing air particles. A filter is sent to an ASHRAE lab, and its efficiency is tested against aerosols at three different size ranges (E1, E2, and E3). A MERV rating of between 6 and 13 generally meets the needs of most residences. The chart displays the static pressure drop curves for filters at four MERV ratings.