Does MERV Even Matter? Choosing the Right Air Filter for Your Commercial Building

Filtration is one of the most important factors affecting the air quality and system performance of installed HVAC equipment. Statistically, units that receive regular preventative maintenance to include quarterly filter changes provide better heating and cooling efficiency, lower energy costs, healthier buildings, and longer equipment life. This is why well-managed commercial buildings follow a strict schedule for filter replacement of installed equipment.

Key Benefits of Regular Filter Changes for HVAC equipment include:

• Cleaner Air for Occupants
• Cleaner Air for Equipment
• Increased Heat Exchange Efficiency
• Increase Temperature Control Ability
• Lower Maintenance Costs
• Lower Energy Use
• Longer Equipment Life
• Maximum Return on Initial Investment

Filtration has long been hailed as one of the core fundamentals of effective air conditioning. Humidity, Temperature, and Air Flow are all critical factors for managing and conditioning the air within an occupied space. Filtration affects the flow of air for better and for worse. Improper filtration results in flow restrictions that can lead to problems with other factors of air conditioning.

All Filters Are Not Created Equal - The use of filters and regular changing is commonplace in most commercial spaces. However, a filter is not just a filter. There are several factors that should be considered when selecting a filter for an HVAC system and choosing the right filter can ensure maximum efficiency along with helping to maintain certain air quality standards to the desired levels.

What does MERV Rating Mean? MERV or Minimum Efficiency Reporting Values indicate the filter's capability to capture particulate between 0.3 -10 microns. Micron (μm) is the term coined for micrometer. As a unit of measurement that equals one-millionth of a meter. To put the size into perspective a grain of salt is an average of around 60 μm. MERV rating provides end users with a scale that can help match their filtration needs. The higher the MERV rating the smaller the particulate that the filter is able to entrap.

MERV ratings are derived from test methods of the American Society of Heating Refrigeration & Air Conditioning Engineers (ASHRAE). The specific rating coincides with what has been proven to be successfully filtered through the various filtration mediums. Most commercial applications of MERV ratings range between 1 - 16, whereas certain critical environments may call for higher MERV ratings or even HEPA (High-Efficiency Particulate Air) filtration.

Choosing the Right Filter for Your Commercial Space

For many spaces, a rating for MERV 6 and up has proven to be sufficient. However other commercial sites may require much higher filtration efficiency. Healthcare facilities, office spaces with numerous occupants, and sites where new or ongoing construction is occurring are all good examples of a space that may need higher MERV ratings along with the correct intervals for replacements. At the end of the day, there's just no one size fits all approach to air filter requirements.

MERV 13 is increasingly becoming the new gold standard for most commercial applications. With the impact and lessons learned through the COVID-19 pandemic facilities have sought out better options to filter carriers of viruses and bacteria. While a filter alone may not mitigate viral threats, it can reduce airborne particulate that may host certain micro-agents that could be present.

It's oftentimes thought that with filtration, more is better. Meaning, why not just go ahead and have the highest MERV rating to support maximum filtration? While this seems like an effective approach, it leads to other problems that have to be considered. Modern air-handling equipment is designed to produce the required air circulation throughout a building via its installed equipment. Adding filtration that is over the manufactures recommended specification can create pressure drops that will lead to other undesired results. So finding the right filter rating to meet the needs of the facility are critical.

Ultimately many factors have to be considered for the selection of an occupied space. Space use, contaminants, and the number or occupants all help determine the right choice. Offices of an industrial machine shop for example may need different MERV ratings or increased frequencies of changes over that of a marketing firm. All environmental effects should be weighed in the process of making a selection.

Keep in mind that one of the fundamentals of HVAC is airflow, clogged or over-rated filters can lead to the system working harder in an attempt to maintain set points and lead to premature failure and increased energy cost. Selecting the right filter for your commercial space and changing them at the correct frequencies based on air-borne contaminants is key to getting the longest life, optimum efficiency, and comfort from your systems. Likewise, as the intent of the filter itself, occupants of these commercial spaces will be in healthier and safer buildings.

Contact Chesapeake Controls Inc . for more information on finding the right filter rating for your commercial spaces. Since 1985 Chesapeake Controls has been committed to increasing indoor air quality in commercial, office, healthcare, and education facilities, through intelligent controls and monitoring equipment along with quality HVAC preventative maintenance. Let our team of experts make your commercial buildings as intelligent, healthy, and efficient as possible.

Visit Chesapeake Controls Inc. on the web for more information.