The chart displays the static pressure drop curves for filters at four MERV ratings. "@type": "Answer", },{ What guidelines are available to compare air cleaners? A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. "acceptedAnswer": { A MERV rating of between 6 and 13 generally meets the needs of most residences. These filters do a good job at removing harmful indoor air pollution. Is it a problem? Browse a full list of industry terms to better choose your filters. },{ The furnace filter frames use a M 10 rated level air filter. This part is common to the three previous studies. 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. Want to work for Air Filters Inc.? 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. 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. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Copyright 2014-2023, PICKHVAC All Rights Reserved. MERV stands for Minimum Efficiency Reporting Value. ), 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/. Generally, filters with higher MERV ratings have less airflow. Most manufacturers recommend ratings of 0.5 or lower for the IWC test. This could be because your system is moving too much or not enough air through its ductwork." 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. Similarly, the medium MERV filters also showed a decrease in airflow . 2/11/20 Use this rating system compare filters made by different manufacturers. To get the right HVAC product and suitable MERV-rated air filter, you should know the area you want to use. ", The health benefits of particle filtration are proportional to "the reduction in total exposure to particles less than 2.5 m in diameter. Watch helpful videos from AFI. This value is used at the filters lowest efficiency. The dirty MERV-8 filters had lower pressure drops than the clean MERV-13s. } 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 you air filter is installed, it is a barrier between your HVAC and your ducts/vents. Restrictive filters are one of many causes for low airflow, but if youve just installed a high-MERV filter and now air isnt flowing very well, this is likely the reason in this instance. Which is not recommended, and could cause increased energy bills, and undue wear on your HVAC unit. 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. 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. "@type": "Question", "@type": "Question", Firstly, MERV ratings range between a 1 and 20 scale, which denotes the effectiveness and efficiency of filters to catch specific air-particle sizes. It should be noted that pressure drop through a high-MERV filter varies depending on the velocity of the air flow. They remove pet dander and most allergy causing air particles. 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. Does the airflow significantly improve? JavaScript appears to be disabled on this computer. A .gov website belongs to an official government organization in the United States. Other materials used for filters have different MERV and air flow (IR) properties. 1.0-3.0 greater than or equal to 95% MERV Rating Chart: How to Choose the Right Air Filter for You? - LakeAir PDF ASHRAE 52 explained - Camfil 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. They specify a minimum MERV of a filter to use, but not the IR. Surface area of the filter. ", Thickness of the filter. "name": "Does the material affect the pressure drop of the filter? "name": "What is static pressure? 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. 2. We offer a variety of high quality Camfil-brand filters that can help you meet the latest filtration recommendations while keeping energy costs as low as possible. The higher the filtering efficiency rating (MERV rating), the higher the pressure drop. 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. When You Shouldn't Use High MERV (12+) Filter for Furnace or AC Thick and high-MERV filters can cause a significant drop in pressure inside your HVAC system from before to after the filter. When selecting the right filter for your application, higher is not always better. Using an air filter with a MERVrating higher than what your furnace or air conditioner manufacturer recommends can actually impair its performance. DC Wire Gauge Calculator: What Gauge Wire (12V, 24V, 48V)? This multi-filter system extends the life of the more expensive final filters, leading to overall cost savings. 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. 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. Our Complete Recommended MERV Rating Guide is a good source for understanding the best filter for your HVAC system. Dust Mites. "text": "When you air filter is installed, it is a barrier between your HVAC and your ducts/vents. 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. If your facility needs to upgrade to MERV 13+, R.P. Air Filter Static Pressure Drop - HVAC School Extended Surface Pleated Filters Standard and high capacity MERV 8, MERV-A 8-A Low Initial Resistance for energy savings . MERV stands for Minimum Efficiency Reporting Value. 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. The scale rates how well a filter removes fine particulates from the incoming air. It shows particle size ranges. 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. In fact, they are high-efficiency filters. Pressure drop occurs, airflow is reduced and system . Actual Size: 23-3/8 x 23-3/8 x 3-3/4. },{ The Chart below shows the scale used to evaluate each of the 6 test cycles. You can help minimize the risk of HVAC equipment issues or damage from pressure drop, by regularly changing your air filter. Pre filters are rated MERV 2. At LakeAir, we recommendMERV 10 filtersas our good air filter. However, one study found that actual pressure drops in home. This is an industry standard rating system. A M rating of 13 through 16 are higher quality filters. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease." The higher the MERV rating the better the filter is at trapping specific types of particles. 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. } 3M Pro Series Residential Air Cleaning Filters 4" and 5" filters last up to 6 to 12 months. 3.0-10.0 greater than or equal to 90%, 0.30-1.0 greater than or equal to 75% in the Inch-Pound system of measurement. Heres the definition of what that actually means: Definition: HEPA filter is a mechanical filter that must remove 99.97% (according to U.S. DOE) of particles whose average size is equal to 0.3 microns. (std. 1-Inch vs 2-Inch vs 4-inch Furnace Filters: Which is Best? The more tightly woven or thick a filters media is, the more particles and contaminates the filter can trap." How often should I change my filter if I have a high MERV rating? MERV Ratings 17-20 reflect values that are used in the rating of HEPA and ULPA filters. The filters initial pressure drop (initial resistance) will vary by the filter type, MERV rating, and size. Use this rating system compare filters made by different manufacturers. P.S. Using the worst case particle size results in the worst case efficiency rating (i.e. Remembering to change your air filter is key to reducing the risk from pressure drop." These filters remove at least 99.97% of dust particle and are capable of removing viruses and radioactive material. MERV Rating Chart: AC, Furnace & Purifier Filters Explained They offer good airflow. "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. HEPA stands for High-Efficiency Particular Air. It isnt easy to navigate through 20 classes of MERV ratings. MERV 8 vs MERV 11 Air Filters: Which Should I Use? | FilterBuy These filters should not be used in home HVAC or furnace systems. The US Department of Energy recommends at least a MERV 8. These ratings lie on a scale of 1 to 20. } Pros. Do High-MERV Filters Restrict Airflow? | HVAC Training Shop Not as taxing on your HVAC system. 3M Filtrete MERV 5 Review Conclusion. They are usually reserved for superior commercial applications. This is usually when the filter is new. According to theAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),this filtration helps provide healthier indoor air quality. Please click here to see any active alerts. 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. The higher the MERV rating, the more particles the filter will remove. ; High-rated media is able to retain fumes . Click the button below to get your discount ! the expression of the Minimum Efficiency Reporting Value (MERV). 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. depth MERV 13 filters are available with pressure drop characteristics comparable to or lower than some MERV 6 filters, staff also finds that a 2" filter depth is valuable in allowing filters to have airflow characteristics that are superior to a 1" filter, and may facilitate use of even higher MERV filters (such as the MERV 16 recommended by Its actually based on the MERV rating. When youre buying an air purifier for a specific purpose, you need to know how big the air contaminants youre looking to remove are. MERV means Minimum Efficiency Reporting Value (MERV) and is an industry standard that measures the overall effectiveness of air filters. to the test filter, expressed in grams, and its average arrestance. As a filter traps and gathers airborne contaminants the filters pressure drop increases and air flow decreases. As you can see from the . ", Typically, the higher the MERV rating, the higher the pressure drop and the more restrictive the air flow is. Note that when the MERV 13 is added, it is more restrictive than either. Is There a Downside to High-MERV Filters? - Home Energy Filters rated MERV 7-12 are typically considered to be suitable for residential HVAC systems. Does merv rating affect airflow? They never need to be replaced. They require special blowers to pull the air through them. This also means that as the MERV rating goes up, the more particles and contaminants the filter can capture. 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. Also, just because a filter fits with a system, that doesn't mean it's the best filter for the system. The air filter's efficiency has an indirect impact on airflow. It ensures reliable and consistent testing of air filter performance. As an Amazon Associate we earn from qualifying purchases. Comparative Tests on Pressure Drop of HVAC Filters Secure .gov websites use HTTPS Has the lowest pressure drop of any fine fiber 4 deep mini-pleated filter. We do not recommend M 12 or higher 13 filters. 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. Pressure Drop inches w.c. 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. // Air Filter Pressure Drop FAQ | Air Filters, Inc. OK ! At the lower end of the efficiency spectrum a fiberglass or polyester panel filter may have a MERV of 4 or 5. This value is helpful in comparing the performance of different filters Average particle size efficiency for 1 size range (0.3-1.0 micron, to be exact). The MERV rating system goes from 1 to 16, with the higher numbers representing filters that can remove smaller particles from the air. ", You must have JavaScript enabled in your browser to utilize the functionality of this website. General ventilation filters | Camfil },{ 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. These particles could hurt health and productivity. . The higher the MERV of a filter, the smaller and the more particles it will remove from the air that passes through it. The "dirt" on the filters adds resistance. 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? } Includes a moisture resistant, high wet-strength beverage board frame. There are a number of factors that determine what the resistance to airflow of a new, clean filter (Initial Resistance, or IR) and the resulting pressure drop will be: 1. What are ionizers and other ozone generating air cleaners? COVID-19, air filtration and energy use - Uptime Institute Blog 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. Our price is lower than the manufacturer's "minimum advertised price." 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. "@type": "Question", 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 Inch-Pound system of measurement. Can I purchase a 2x14x20 air filter with rating of 20, or 30 if possible, online? },{ "name": "What initial pressure drop vs. final pressure drop? Manufacturers are in continual competition to try to provide the best of both worlds in this area. You will find exactly the same MERV rating chart there in a bit more technically language. "@type": "Question", 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. What Are All Those Gadgets On A Multitool? It also shows air filter efficiency levels. Well also look into how high a MERV rating an air purifier should have to best filter out different air contaminants (pollen, mold spored, smoke, dust, etc.). 95% Air Filter, MERV-14, MERV-15, or MERV-16 - Yes? Because the pleated design creates more surface area, which is a less restrictive design. Relationship Between Pressure Drop and MERV Rating (+Chart) In other words: HEPA filters are better than anything MERV rating can measure. The vertical axis shows system static pressure drop by 0.1 inch w.c., and across the horizontal axis it shows system air flow in cubic feet per minute (CFPM). The higher the MERV, the smaller the particles removed, and the more of them removed. What is a MERV rating? | US EPA What are they and why they matter? 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 resulting rating is theen given to each filter. Thanks for any clarity. Weve identified that there is an increase in pressure drop and energy costs when switching to MERV 13 or higher filters. MERV 13 Filter Pressure Drop: Guidance for Facility Managers - R.P. Fedder The majority of residential HVAC systems use a 1" thick filter, but filters are available at 2", 4" and 5" thick. The pressure drop across the MERV-13 filter was 0.0274 inch of water column. A MERV 8 filter can remove particles down to 3 microns in size at an efficiency of 70% or greater (1 micron is about 0.04 thousandths of an inch). "text": "Static pressure is the measurement of the exertion of air flow your HVAC system is moving throughout the system and ductwork." The MERV rating is a scale from 1 to 16, with the higher numbers being the most efficient at removing particles. } ", A position paper published by ASHRAE looked at the claim that particle filtration has health benefits. "text": "The higher the MERV rating the more efficient the filter is at filtering out and capturing air particles and contaminants. While it is not important to fully understand the comparison chart, it is good to familiarize yourself with it. 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. How efficient the filter is against all three size ranges is compared against a MERV chart and the final MERV value is the highest value where the filter meets all three requirements of MERV. The Complete Air Filter MERV Rating Chart - Grainger KnowHow "mainEntity": [{ 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). This is how they get the name MERV (MINIMUM Efficiency Rating Value). Grainger Editorial Staff. Categories Pollutant. Our filtration specialists can help you determine the right air filter strategy for your facility. Install the test filter in the test duct and obtain clean air filter resistance or initial pressure drop. The manometer below shows my reading across one of the clean MERV-13 filters. A filter's MERVnumber indicates how it's rated to remove these particles. This often coincides with a higher MERV rating; however, this also means that the filter is slightly more restrictive and the airflow rate through the filter is lower. "acceptedAnswer": { 2. Pleats look like an accordion, and can more than double the face area of a filter. Average 1-6 Person Home kWh Usage, Gas Vs Electric Water Heater Monthly Cost Comparison (State-By-State), Water Heating Costs For 1,2,3,4,5,6 Family Homes (State-By-State Analysis), Electric Water Heating Cost, kWh Usage Per Month (State-By-State RECS Analysis), What Is W2 Wire On Thermostat? This is an industry standard rating system. 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? Best Merv 16 Furnace and Air Conditioner Air Filter Do high merv filters restrict airflow? - merv-ratings.com The E3 arrestance describes how well an air filter removes larger particles such as dirt, lint, hair, and dust. Once the filter is fully loaded the filter will reach its final pressure drop. 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. 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. In some ways they are better than all media filters in others they have drawbacks. 3.0-10.0 greater than or equal to 95%, 0.30-1.0 greater than or equal to 95% Save my name, email, and website in this browser for the next time I comment. Frequent filter changeouts will help minimize risks from pressure drop. 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. What Is an Air Filter MERV Rating and Why Is It Important to - Yahoo! The most prevalent MERV ratings are MERV 4, 6, 8, 10, 12, 14, and 16: A Higher MERV rating automatically means a better filter. 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. 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." Of course, the ultimate choice needs to take the capabilities of the HVAC systems into consideration. The higher the number, the better the filter is at capturing larger particles between 0.3 and 10 microns (m). 1994-2021, W.W. Grainger, Inc. All Rights Reserved. } As air moves through an HVAC system and encounters a filter, the filter creates resistance to the airflow as it removes particles and contaminants from the air. There is still a common misconception that having a high MERV rated filter will be too restrictive and strain your unit. 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. Here's what you're not being told. "name": "What is the relationship between filter pressure drop and air flow rate? Particle filtration can be "modestly effective" against allergy and asthma symptoms. = 4.5 x CFM x h (std. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease. It is quite an important filter-specific factor. Spun fiberglass almost always has a lower IR than other materials. This will be determined by both the frame size of the filter (usually close to the size of the return duct), and whether or not the filter has a pleated surface. Standard 52.2 establishes a testing protocol. MERV stands for Minimum Efficiency Reporting Value. Simple use of MERV rating chart for air purifier filters: The higher the MERV rating, the better the filter. These particles are 1-3 microns. Hi Diane, MERV 20 are highly specialized filters and are not sold online. The MERV filter rating measures the amount of microparticles and macroparticles in the air from 0.3 microns and 10 microns in size. How do I know if I need a higher MERV rating? Many pleated HVAC air filters can still have a high MERV rating, while not drastically restricting air flow. The COVID-19 pandemic has caused concerns about data center HVAC (heating, ventilation and air conditioning) filtration. They also found that air flow in the high-MERV filters dropped by 7% and 11% in the two HVAC systems compared to the low-MERV filters. What MERV filter is recommended for preventing the transmission of airborne illnesses such as COVID-19? We are hiring! MERV rating. They are used in light industrial and residential applications. The test begins with a clean filter. As the MERV rating increases the finer the filtration becomes. High-MERV Filter | Building America Solution Center - PNNL
