How To Determine H2S Concentration and Airflow CFM
Other than the vent pipe size, to accurately size any of our larger adsorbers, you will need to know two other things: a) the velocity of the air moving through the vent; and b) the concentration of the hydrogen sulfide (H2S) in the airstream. Homeowners generally do not have to worry about these numbers. If your problem is imminating from a single-family home without extenuating circumstances, one of the four featured filters on our residential septic odor solutions page should work for you.
In the event that you don't have the necessary tools to measure the H2S concentration and the CFM of the airflow, below are a couple of products that can help you in accessing your situation.
Measuring the H2S Concentration
Measuring the concentration of hydrogen sulfide (H2S) in a septic vent airstream can be accomplished
using portable H2S detectors which are commonly available and provide real-time readings. They are suitable for monitoring in environments with
varying concentrations. You can find these on Amazon and other websites. Here is a link
to an H2S concentration meter on Amazon.
Determining the Airflow (CFM)

- Insert the anemometer into the vent pipe.
- Measure air velocity in cubic feet per minute (CFM) at multiple points across the cross-section of the vent.
- Calculate the average velocity from these measurements.
Before starting any measurement, ensure safety protocols are in place, as H2S is toxic. Consider conducting measurements during periods of typical venting activity to get accurate representations of concentrations. Here is a link to an anemometer Amazon.
Simple Solutions Distributing LLC does not receive remuneration for these links to Amazon.