One of the most vital safety equipments in laboratories is the fume hoods. Fume hoods are extremely important because they help to purify the air that is inside the laboratory and clean it from any sort of contaminants and pollutants. These contaminants might be bi-products of laboratory tests and experiments. They are often toxic for human beings and hence people who work in the laboratories will be at risk of getting contaminated with these harmful and poisonous substances.
There are a lot of stringent quality tests which a lab fume hood must undergo before it can be deemed to be safe for use in laboratories. One of the most important tests for this purpose is the Ashrae 110 method of testing performance of laboratory fume hoods. In this article you will be learning more about this.
What is the Ashrae 110 method?
The ASHRAE 110 method for testing performances of the lab fume hoods is perhaps the most popular and commonly used method for testing and evaluating a fume hood’s performance. In this method, the test mainly will evaluate the ability of the fume hoods to be able to not only contain fumes but also exhaust them. Also there are a strict set of pre-conditions under which these tests are taken.
The AHRAE mode of testing will be used for commissioning and then certifying the installations of fume hoods. It will be one of the main tools which would be used for the manufacturers to use while designing, researching on and developing the fume hoods. The government agencies of several countries have adopted the ASHRAE method for the official evaluation standards for testing the performances of laboratory fume hoods.
There are three main standards of testing in the ASHRAE 110 method:
- Measurement of the Face Velocity
- Smoke Visualizations Technique
- Containment of Tracer Gas
Features of the Measurements of Face Velocity:
- There are several different point readings of the face velocity which are all taken for calculating an average value of the face velocity
- Measurement of all the cross drafts
- Verification of the VAV systems, its operations and responses
- Calibration of the fume hood and the air flow monitor
Features of Smoke Visualizations:
- Smoke stick tests
- Testing of the Dry ice
Containment of the Tracer Gas:
- SF6 gases (Colourless and Odourless) would be used for conducting this tracer gas containments tests.
- This gas is required to be ejected inside of the fume hoods with a specific standard pressure.
- A Mannequin would then be placed near the fume hoods in a specified standard distance and an easy pickup probe will get fixed. This probe will be connected with the unit of the SF6 Gas analyzer.
- The testing would be done for about five minutes in order to see the general escape rating.
- Gas analyzers will measure the concentration right down to about 0.01 PPM.
This is a very strict test and it ensures that the laboratory fume hoods are performing properly and can provide safe air in the laboratory environment.