MERV values range from 1 (minimal filtering) to 20 (maximum filtering). "acceptedAnswer": { They are used in light industrial and residential applications. 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. 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. This is important to consider when choosing a filter for your application and your HVAC unit. = 4.5 x CFM x h (std. Do I Really Need to be Concerned with the MERV/Pressure Drop Issue? "@type": "Answer", "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. This method tests Air-Cleaning Devices for dust removal efficiency. Electrostatic air filtration is not easily compared to media filters. The E3 arrestance describes how well an air filter removes larger particles such as dirt, lint, hair, and dust. ", Higher pressure drop = less airflow . Filters rated MERV 7-12 are typically considered to be suitable for residential HVAC systems. Particle filtration can be "modestly effective" against allergy and asthma symptoms. Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings. "mainEntity": [{ What was their secret? Use this rating system compare filters made by different manufacturers. 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? These air filters are used to protect people or products from airborne contaminants. You can check the whole EPAs list of air pollutants here. When used as final filters, they are the primary filters for an HVAC system. "@type": "Answer", So, you just purchased some new filters for your home HVAC system. 1.0-3.0 greater than or equal to 90% 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. What are ionizers and other ozone generating air cleaners? "acceptedAnswer": { The higher the MERV number, the smaller the particles the filter can trap and the more of them. And MERV-13* is practically where you want to be. Use this rating system compare filters made by different manufacturers. Consider the following MERV 13 pressure drop chart, comparing a high quality Camfil MERV 13 filter vs. a lower quality MERV 13 filter. These values were correct at the time of printing and Filtermakers do not accept any liability for any information provided herein. Q: Can HVAC operations strategies help prevent the spread of COVID-19? Refer below to four average contaminant size intervals for MERV rating consideration. Most current household HVAC units/handlers can handle a MERV 6-13 pleated filter with ease. The chart also provides instructions on how to determine electric fan energy consumed by AHUs in your own facility. The amount of the HVACs air flow slowed by the filter is equivalent to the filters pressure drop. That will definitely increase the pressure drop and place unwanted strain on your HVAC system. "name": "What is the relationship between filter pressure drop and air flow rate? At LakeAir, we recommendMERV 10 filtersas our good air filter. Industrial HVAC air filters are installed in commercial HVAC systems to remove airborne contaminants from the air stream. 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. 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. "text": "Filters use various types of medias depending on the application or what the environment requires. ". The higher the MERV, the smaller the particles removed, and the more of them removed. The higher the pressure drop the more restrictive the filter is to air flow. Available in a variety of sizes for virtually any application. "@type": "Answer", Get more great content like this sent to your inbox. Can I purchase a 2x14x20 air filter with rating of 20, or 30 if possible, online? These filters should not be used in home HVAC or furnace systems. As the MERV rating increases the finer the filtration becomes. 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." As an air filter manufacturer, we are uniquely positioned to custom make any and all types of air filters. 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 higher the filtering efficiency rating (MERV rating), the higher the pressure drop. Using an air filter with a MERVrating higher than what your furnace or air conditioner manufacturer recommends can actually impair its performance. Generally, increasing filter efficiency leads to increased pressure drop which can lead to reduced air flow through the HVAC system, more . How to Tell if I Should Change Furnace Filter. The lower the pressure drop the easier it is for air to flow through the filter." MERV 9 through 12 filters are good filters for general home use. Increased efficiency of the HVAC system a higher MERV rating means that the filter is able to capture more particles, which leads to a more efficient HVAC system. 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. 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%. A filter's MERVnumber indicates how it's rated to remove these particles. They are washable. In particular, using an air cleaner with a MERV rating that is too high can damage the compressor, heat exchanger, and air conditioner coil. ", } 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. A filters pressure drop changes throughout its use. "@type": "Answer", 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. During each cycle a predetermined amount of dust particles is released into the airstream. "name": "What is static pressure? LakeAir provides discounts to Veterans, First Responders, and the Elderly. HEPA, ULPA, and ASHRAE filters are typically used in commercial and industrial environments or in applications. What are the benefits of a higher MERV rating? The wasted energy (and associated energy bill costs) required to push air through a higher MERV-rated filter to overcome the increased pressure drop shocks some owners. 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. Most manufacturers recommend ratings of 0.5 or lower for the IWC test. 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. Includes a moisture resistant, high wet-strength beverage board frame. Doing so could cause strain on your HVAC unit and could cause costly maintenance and repairs." 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. (std. 52.1-1992 ASHRAE Test Procedure ATMOSPHERIC DUST SPOT EFFICIENCY 1. MERV Rating Chart: How to Choose the Right Air Filter for You? "name": "What are the signs of unhealthy static pressure in an HVAC system? 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). A .gov website belongs to an official government organization in the United States. The MERV filter rating measures the amount of microparticles and macroparticles in the air from 0.3 microns and 10 microns in size. The scale rates how well a filter removes fine particulates from the incoming air. 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. Hot or cold spots throughout your home? Typically, the higher the MERV rating, the higher the pressure drop and the more restrictive the air flow is. Remembering to change your air filter is key to reducing the risk from pressure drop. 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. As you can see above, research shows that in general, HVAC systems with high MERV* filters have a higher pressure drop across the entire filter. Their cost is often moderate and are within many budgets. Install the test filter in the test duct and obtain clean air filter resistance or initial pressure drop. THE PRODUCTS YOU NEED, The filter is assigned a value based on the test. Check your filter at least once a month for dust buildup. "@type": "FAQPage", But what is MERVrating, exactly? Pollutant Size. However, one study found that actual pressure drops in home. In addition, poorly designed and installed duct systems already have external static pressures that are too high. For a product to be called Made in USA, the product must be all or virtually all made in the U.S. Each filter is assigned a rating based on how much debris a filter manages to block when circulating air. 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. Cookies Policy. Follow manufacturer's recommendations on maintenance and replacement. 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. Pressure drop directly corresponds to a filters air flow rate. 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. "@type": "Answer", "acceptedAnswer": { Leadership in Energy and Environmental Design (LEED) also recommends a minimum of MERV 8. The MERV rating is a scale from 1 to 16, with the higher numbers being the most efficient at removing particles. Air filters can be used as final filters or pre-filters. Because the pleated design creates more surface area, which is a less restrictive design. "acceptedAnswer": { Typical Applications. ", This is how they get the name MERV (MINIMUM Efficiency Rating Value). 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.). In fact, some MERV 8 and MERV 9 filters have similar or higher pressure drops than the MERV 13 filters. "text": "The pressure drop of a filter is a measure of its resistance to airflow through it. Does the airflow significantly improve? "acceptedAnswer": { Most current home HVAC units can accommodate a filter with a MERV 13 or lower. This rating system reports how well the filter captures and holds dust. "@type": "Answer", What is interesting is that youll rarely see MERV rating in an air purifier specification sheet. What is a MERV rating? "@type": "Question", 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. "@type": "Question", "@type": "Answer", "@context": "https://schema.org", Likewise, the mid-MERV filters also showed decreased air flow relative to the low-MERV filters, this time 3% and 8% lower in the two systems. It is not recommended to continue to use your filter beyond its final pressure drop point. The test results are then used to give a filter its MERV rating. I normally see a product spec sheet with ASHRAE 52.2 testing, but I dont normally see Appendix J associated with it. If we were looking to buy a new filter today for our HVAC (heating, ventilation, and air conditioning) system, we'd aim for a medium-efficiency filter with a MERV rating in the 8 . The Chart below shows the scale used to evaluate each of the 6 test cycles. ", Want to work for Air Filters Inc.? In fact, they are high-efficiency filters. 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. "text": "Static pressure is the measurement of the exertion of air flow your HVAC system is moving throughout the system and ductwork." 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. Our test duct is 8 feet long, two feet wide and two feet high. 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. }] WHEN YOU NEED THEM. The lower the pressure drop the easier it is for air to flow through the filter. There are no products matching the selection. Depending on the design [] Since filters with a higher MERV can trap smaller particles, it is often assumed that they will automatically have a greater resistance to air flow. 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. 1-Inch vs 2-Inch vs 4-inch Furnace Filters: Which is Best? 3M Filtrete MERV 5 Review Conclusion. Pressure drop directly corresponds to a filters air flow rate." Because they go off the MERV chart, they are referred to as HEPA filters or high-efficiency 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. Do you know what could happen if you didnt get the right ones? Arrestanceis a measure of the ability of an air filtration device to dust from the air. Firstly, MERV ratings range between a 1 and 20 scale, which denotes the effectiveness and efficiency of filters to catch specific air-particle sizes. The chart below shows a detailed description for each MERV rating 1 through 16. Please click here to see any active alerts. CFM Calculator Calculate Clean Air Flow. Save my name, email, and website in this browser for the next time I comment. Other materials used for filters have different MERV and air flow (IR) properties. JavaScript appears to be disabled on this computer. As a filter traps and gathers airborne contaminants the filters pressure drop increases and air flow decreases. 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. For comparison, a grain of sand is about 60 microns. It can remove small particles such as dust mites, spray paint dust, carpet fibers, and pollen. Improved indoor air quality by capturing more particles, a higher MERV rating results in cleaner air being circulated throughout the home or office. } We are hiring! The air filter's efficiency has an indirect impact on airflow. Hi Nash, ASHRAE 52.2 is the source of all MERV effectiveness data. The resulting rating is theen given to each filter. } 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. The furnace filter frames use a M 10 rated level air filter. You will find exactly the same MERV rating chart there in a bit more technically language. air), Latent Heat (BTU/hr) = 0.69 x CFM x gr. You can help minimize the risk of HVAC equipment issues or damage from pressure drop, by regularly changing your air filter. 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. "name": "Do higher MERV rated filters restrict air flow? "acceptedAnswer": { "acceptedAnswer": { This value is used at the filters lowest efficiency. According to theAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),this filtration helps provide healthier indoor air quality. If you have more questions about the right air filter or air purifier, call our customer service number 800-558-9436. A filters pressure drop directly corresponds to a filters air flow rate. } The key is to look at the ratio of the filter area to the air flow rate. 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. ASHRAEdeveloped the MERV air filter efficiency rating system. It holds 24X24 filters with a depth of up to 20. ", } MERV stands for Minimum Efficiency Reporting Value. Why? Changing your air filters regularly will prevent filters from being loaded and overly restrictive. Thickness of the filter. },{ Every air purification system should have an activated carbon filter. The higher the pressure drop the more restrictive the filter is to air flow. The test is made of six cycles. Pleats look like an accordion, and can more than double the face area of a filter. Airflow through the vents is lower: Is the new filter causing low airflow? 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). 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. The higher the filtering efficiency rating (MERV rating), the higher the pressure drop. From ASHRAE Journal Newsletter, December 8, 2020 . This website uses cookies. What if they cause too much pressure drop? // ]]>. "@type": "Question", "acceptedAnswer": { "name": "What is filter pressure drop?