"name": "What is static pressure? 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. Remembering to change your air filter is key to reducing the risk from pressure drop. The test results are then used to give a filter its MERV rating. The Chart below shows the scale used to evaluate each of the 6 test cycles. 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. They are used in light industrial and residential applications. "name": "How is filter pressure drop measured? Standard 52.2 establishes a testing protocol. The rating describes a filter's effectiveness at removing particles from the air. 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). You must have JavaScript enabled in your browser to utilize the functionality of this website. When selecting the right filter for your application, higher is not always better. Pressure drop describes what happens when air pressure is decreased from one section in an HVAC system to another section downstream. Their rating is based upon filtering out a particular size of air particles, 0.3-micron ones. This depends on a variety of factors, including the type of air filters you have, the size of your home, the number of people in your household, the presence of pets, and your own personal preferences. LakeAirElectrostatic Air Filterswork as well as a MERV 16 air filter. 1.0-3.0 greater than or equal to 90% Source: www.doityourself.com. Grainger Editorial Staff. 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. These are the smallest particles that both FPR and MERV-rated air filters will be able to pick up. filtration helps provide healthier indoor air quality, Learn more about these recommendations here, recommendations for filtration, humidity set points, automation and more. The chart below shows a detailed description for each MERV rating 1 through 16. } Filters use various types of medias depending on the application or what the environment requires. MERV rating ranges between 10 and 12 are suitable for removing a broad range of particles. Hot or cold spots throughout your home? Changing your air filters regularly will prevent filters from being loaded and overly restrictive. Filters with higher MERV ratings are more restrictive because they are capable of filtering more particles than filters with lower MERV ratings. These filters do a good job at removing harmful indoor air pollution. Pollutant Size. ", MERV stands for Minimum Efficiency Reporting Value. You can learn how to measure the air filter static pressure drop by watching THIS video. HEPA and ULPA filters are represented in the 17 through 20 ratings. Higher pressure drop = less airflow . A position paper published by ASHRAE looked at the claim that particle filtration has health benefits. = 4.5 x CFM x h (std. 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). What is interesting is that youll rarely see MERV rating in an air purifier specification sheet. 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 . Air filter selection chart and Performance Ratings. Once the filter is fully loaded the filter will reach its final pressure drop. When used as final filters, they are the primary filters for an HVAC system. 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. While that can happen, it most likely will not be a result except under extreme circumstances involving a cheap blower motor and the concern addressed below. },{ 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. For example, if bacteria ranges from 0.3 microns to 4 microns, the chart indicates a MERV 13 would be the minimum rating to select, and higher MERV-rated filters should be selected with the end users' level of comfort and The Air Conditioning Contractors of America assumes that the pressure drop across a . "acceptedAnswer": { At LakeAir, we recommendMERV 10 filtersas our good air filter. 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. Is it a problem? They are washable. Using an air filter with a MERVrating higher than what your furnace or air conditioner manufacturer recommends can actually impair its performance. MERV stands for Minimum Efficiency Reporting Value. Average particle size efficiency for 1 size range (0.3-1.0 micron, to be exact). If a system is designed with a standard filter for that pressure drop, the pressure drop with a pleated filter of the same size will most likely be higher. 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). Riga-Flo For instance, the most common cause of pressure drop is a dirty filter and some low-quality MERV 13 filters will clog more frequently, leading to increased pressure drop which requires more frequent filter replacements. Guaranteed against media pack failure to 5.0 w.g. 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. //