The ducted fume hoods are the most common form of fume hoods which are used in laboratories all over the world. These fume hoods are fixed in a specific position and have a duct system in place, through which the fumes are expelled out. The fumes go out through the ducts and out of the building, thereby keeping the insides of your lab safe from toxicity. These types of fume hoods will require certain additional services like ductwork, fans for exhaust, mechanical systems and so on. As a result of this, it will be a big investment to setup ductless fume hoods in your lab. Thus, it is essential that you make all the necessary considerations before installing ductless fume hoods. In this small article, you will learn more about choosing ductless fume hoods.
Placing your fume hoods at the correct location: Before you purchase your fume hoods, it is important to decide where you will be placing the hoods. Various states and countries have specific regulations regarding the location of fume hoods for labs. When you are deciding upon the position of your fume hood, you must consider the following details also:
Nearby traffic areas - You will have to ensure that there are no large scale vehicular movement immediately besides the fume hoods. There has to be a minimum of 1 meter distance between the sash, that is the barrier between the researcher and his experiment, and an area of traffic. Certain regulations also specify the distance for the traffic area to be a minimum of 5 meters.
Benchtop proximity - In the event that your fume hood is close to a bench top, then you will need to ensure that there exists a minimum distance of 1.5 meters between the sash and your bench top. However, this rule is more commonly applied in the event when the same operator is using both fume hoods and bench tops.
Obstructive devices, walls, other workers - You must take care to ensure that there are no walls, obstructive devices, or other lab operators immediately opposite to the fume hood. You should ensure a minimum of two meters from the sash to the wall. Other lab operators must also not be directly in the line of the exhaust.
Closeness to other forms of obstacles: It is also important that you should see that there are no forms of architectural obstacles in the line of your fume hood. These obstacles include:
Walls with other fume hoods - The fume hood must not be closer than at least 300 mm from both the side of the fume hood. And no obstructive walls should extend past the lines of the face of the ductless fume hoods.
Doorways – The doorways cannot be within a distance of 1.5 m from the sash and has to be at least 1 m away from the sides of the fume hood.
Access for maintenance - You will need to ensure that the fume hoods must have enough access for allowing easy maintenance works.
Testing Fume Hoods : In order to be compliant with the government standards for installing fume hoods, it is important that you conduct proper testing to check the functionality and ventilation. The tests include a smoke test, noise level, illuminance and face velocity. Government authorities have specific guidelines with regards to who can conduct these tests. The results of the tests will have to be recorded and lab managers need to go through them and be cognizant of the results.
Maintaining your fume hoods: Aside from commissioning the fume hood, it is also essential that you can subject the fume hoods to timely maintenance and regular testing. During the period of the maintenance work, you will need to ensure that the fume hoods are disconnected from power sources and there are signs displaying that the fume is "under maintenance" so that lab workers do not try to use them by mistake. You should ensure that no chemicals are inside the fume hood during the testing phase. You will need to do at least a test every six months and submit the reports to the lab managers.
Conclusion : Thus, there are several aspects to using fume hoods in your lab. The ducted fume hoods are going to be a big investment for your lab and so you need to make a thorough plan with regards to how you will be using it and where you shall be placing it before you invest your hard earned money into the devices. Always ensure that only competent persons are installing your devices. A thorough planning will ensure that you are aware of all the essential aspects that you need to consider before you decide to buy a ducted fume hood. Hopefully, the information mentioned in this article will have helped you.