Why We Test
Without testing there is no way to know if a hood is performing safely. And not just any testing. A hood is working safely when there is no/minimal loss of containment. And since there is no relationship between face velocity and containment, we need to do containment testing. We can do the standard ASHRAE 110 testing using SF6 (Sulfur Hexafluoride) but since it is very expensive, requires a lot of equipment and training and it is a very strong greenhouse gas, many are moving away from it. So a new solution was needed.
We had been using lasers and smoke to detect turbulence which is the primary cause for loss of containment. But it took a trained tester and often the results were not repeatable. We knew we needed something simple, inexpensive and repeatable, so we developed the Tri-Color Airflow Visualizer to make containment testing easy.
This test method is simple enough a 5th grader can do it. And because of its highly visual results, you don’t need to be a hood expert to know if your fume hood is containing. If you can see a problem, you can fix it.
If your testing consists of an average face velocity and maybe some local smoke then you are not testing containment and there is no way to know if the hood is performing safely