AHU air purifier: HEPA filter, activated carbon, ionic
Lenntech
Odor is a very complex matter to quantify and qualify. It varies from person to person what is considered smelly. A malodorous substance called mercaptanes can be very pungent at extremely low concentrations of for example 5 ppb (parts per billion). Other bad odours such as H2S loose their smell at very high concentrations.
