WHAT IS THE DIFFERENCE BETWEEN HEPA AND MERV FILTRATION FOR FACILITIES

One major step towards significantly improving indoor air quality is the upgrading of a building’s HVAC and filter to one that is rated at MERV 13 level or higher.

MERV stands for ‘minimum efficiency reporting value’, and a MERV 13 filter is effective at capturing more than 75% of particles sized 0.3 to 1 microns which means it is reasonably effective against mould spores, bacteria and smoke.  However, the Sars Cov 2 virus and Influenza particle size is around 0.1 microns, so whilst a MERV 14 filter is definitely a step in the right direction to improving indoor air quality, it is not as effective at capturing smaller virus sized particles and other airborne allergens that cause respiratory problems.

Another challenge with upgrading HVAC systems in addition to the very high installation and maintenance costs of new filters, is that often the existing fans are not designed to cope with more than MERV 8 or MERV 9 filtration, so the new filters end up doing more harm than good as well as reducing the amount of airflow that is required.  Many facilities are limited to the filtration they can use in their existing systems, so are looking at alternative options.

Here is where the benefits of portable HEPA (high efficiency particulate air) filters comes in.  HEPA filters are essentially the ultimate solution in the air purification world and far exceed what a MERV 13 filter is able to do. All HEPA filters have a rating of a MERV 17 or higher. A HEPA filter with a MERV 18 rating will trap 99.997% of air particles that are 0.3-1.0 micron in size and an even better % of particles below 0.3 microns. The ability of HEPA filters to capture extremely small airborne particles like viruses and bacteria is why they are used in hospital operating rooms to reduce infection risk.

Unfortunately most HVAC systems cannot take retro fitted HEPA filters as the filter media is too fine to allow the desired airflow and ventilation.  The best way to add HEPA filtration and air purification into a facility is through standalone portable HEPA units with their own dedicated fans especially designed for the increased resistance of this filter type.

Zonitise range of medical grade air filtration devices have HEPA filtration rated at 99.997% effectiveness.  This allows any type of building to easily and economically upgrade to the cleanest air quality without having to do a costly redesign of the current HVAC system.  Furthermore, with easily movable devices you can choose where to locate them where they will be of the most benefit.

Portable HEPA devices have been proven to significantly reduce absenteeism by eliminating airborne germs and pathogens that cause respiratory illnesses in many types of environment.  The investment into these systems goes a long way towards providing the best quality of air and all users within a facility.