The Pro Kit is able to neutralize a space of 375m3 or 13,000ft3*. The oil will last between 4-6 weeks with 24 hour use. It only requires 1 hour for the room to be fully neutralized and smell free.
The Neutralizer works in a specified amount of space, and the number of units required will be determined by the density of smell or number of smell sources in the room.
Like with an AC unit, and as an example, an office of 4 people may require 3000BTU output to cool it. However, an output of 3000BTU would not be sufficient if there were 25 people in that room.
The Neutralizer functions in the same way. So if you happen to notice unwanted smells in the correct sized space, it may be the odour density is too strong for 1 unit; add an extra Neutralizer to your space.