Frequently asked Questions About Fume Hood Monitors

In recent months we have received a number of questions from fume hood owners who are very concerned about the safety and compliance of their fume hood monitors. For your convenience, some of their questions are recorded here.

Do I have a CAV or VAV fume hood?

Chances are that you have a CAV (constant air volume) fume hood. These devices have a fan that on the roof that runs at a continuous speed. Raising and lowering the sash changes the face velocity. Many older fume hoods are CAV.

VAV (variable air volume) hoods are programmed to maintain a constant face velocity (airflow at the open sash) as the sash moves. These are useful for conserving utilities costs.

If you have CAV, select from our featured fume hood monitors . If you need a VAV monitor, call us at 888-327-4295.

I have a monitor already. Am I compliant with California law?

Almost. If the current monitor measures actual air velocity and can be calibrated, you are already compliant with respect to the hardware requirement of the new law. However, if you haven’t put into place a testing program for the flow monitor, do it soon.

How do I know that I need the bracket kit?

Many fume hoods have a pre-cut knockout panel on the side post, about the size of a single electrical receptacle. This looks like a hole with a solid plate fastened behind it. Monitors are installed by knocking out the back plate, and inserting the monitor in the hole. This type of installation does not require a surface mounting bracket.

Fume hoods without the knockout require the surface bracket kit.

Do you install?

No we don’t. Many larger institutions have facilities maintenance or HVAC personnel who are trained in the maintenance, calibration, and repair of laboratory fume hoods.

On our web site we have a list of companies that are members of CETA International, the Controlled Environment Testing Association at The non-profit Association is devoted to promoting and developing quality assurance within the controlled environment testing industry includes fume hood and bio-safety cabinet certifiers, laboratory safety professionals, industrial hygienists, facility engineers and control personnel. They are an excellent resource of trained and experienced laboratory service contractors, who will install your monitors, calibrate them, and certify the performance of your fume hood.