Proper Air Filter Selection

Industrial and commercial indoor air quality is a subject of great importance given the number of hours we spend in these locations. In years past, we spent the majority of our time outdoors. Today it has been estimated that we spend the majority of our time indoors, sometimes exceeding 90%. When we couple this with the fact that today we are building more energy efficient “tighter” buildings it is not difficult to see the importance of IAQ, especially given the total number of hours per year we spend in the workplace environment.

There are several ways to improve indoor air quality. One of the best is air filtration. Among the contributors of poor air quality in the industrial environment is particulate matter (PM) which is generated in many different ways. For example, it is often the product of various manufacturing processes such as machining and welding. Smoke and mist are made up of particles. Particulate matter irritates the respiratory system and can lead to infection and illness. Air filtration systems when properly installed and maintained with the correct filters reduce particulate matter in the indoor environment. One of the primary ways to control air quality in a building is by the installation of the correct filters in the HVAC systems. The goal to keep in mind and strive for is the reduction of particulate matter in the indoor environment and we can accomplish this with the proper air filtration system and filters.

The first step in selecting the proper filter is to determine the objective for the filtration system. What is the application and what is its target particle size? Obviously, a healthcare facility will have different applications than a manufacturing plant and thus different filtration and particle size requirements. Most healthcare facilities will have a target particle size of one micron because 99% of all known bacteria are one micron and larger. Seek to identify just what the pollutants are and their particle size. The use of a test instrument to determine particle sizes and counts can be helpful in making this decision but is often not necessary.

Once the objective has been determined, the accompanying chart will be helpful in determining the correct MERV efficiency and filter that will remove the target particle. Locate the contaminant or close approximate in the application guidelines column and select the appropriate MERV filter from the first column. The chart also gives some typical applications for the various MERV filters.

Filters rated for MERV 13 and higher typically are used in conjunction with a prefilter to maximize their service life and minimize costs.

Contact us for assistance in the process of filter selection. We can assist you in identifying the target particle size and the selection of the proper MERV filter for your application.

Proper air filtration remains one of the primary ways of maintaining healthy indoor air quality (IAQ). The proper application and use of air filters in the HVAC, ambient air cleaners and mist collectors will go a long way towards maintaining a “healthy building”.