Are Your Main Dental Office HVAC Filters Adequate?

MERV Rating

ASHRAE pioneered a filter rating system named a MERV rating. The fraction of

particles removed from air passing through a filter is termed “filter efficiency” and is

provided by the Minimum Efficiency Reporting Value (MERV) under standard

conditions. Buildings commonly have MERV 6 or MERV 8 filters. Most dental offices

do not employ HEPA rated filters.

Dental Office Air Filters

Consider the need to sustain proper air flow, maintain room air change rates, and

permit proper heating, cooling, and humidity control when evaluating filter upgrades.

Filters with MERV ≥13 (or ISO equivalent) are efficient at capturing airborne viruses.

A minimum MERV 13 or better is desirable, but increased filter efficiency may result in

increased pressure drop through the filter. Depending on the system, this may result

in lower airflows.

To help decide whether a given HVAC systems can handle filter upgrades without

negative impacts to pressure differentials and/or air flow rates prior to changing filters,

consult with HVAC specialists including ASHRAE professionals. Improved filter

technology has resulted in some MERV 13 filters having similar pressure drops to

older technology MERV 8 filters. This fact, coupled with adjustments to the HVAC

system fan speed, can enable higher filtration rates than were previously used