Instruction to select right Fume Hood

Article by Nguyễn Vũ Hoàng Duy at 15.08.2021
Instruction to select right Fume Hood

Instruction to select right Fume Hood

Choosing a fume hood seem like a daunting task. There are so much information to gather in order to make an informed decision. But fear not, help is at hand!

First, spend a few minutes answering these questions. When you have answered all questions, you will have successfully established the criteria necessary for choosing a fume hood system. Then contact fume hood supplier, and they will make the best product recommendations based upon your answers.

1. What will you be doing inside the hood?

Try to document as much as you can about the application. What chemicals are used, and how are they used? Is heat involved? What volumes of chemicals will be used at a given time? Most importantly, know the answers to the following questions:

  • Do you use Perchloric Acid? The Perchloric Acid Fume Hood needs a built-in spray system to prevent the dangerous forming of Perchlorate salts which can cause explosion.
  • Do you use highly corrosive acid or base? The strong acid or base can corrode the electrogalvanised steel or even the Stainless Steel for a long period of usage. The Polypropylene Fume Hood can provide the corrosive resistance advantage thanks to its material Polypropylene.
  • Do you carry out burning experimental inside the hood? If yes then the Stainless Steel Fume Hood is a good recommendation.

2. What size of fume hood do you need?

  • How wide do you want the fume hood to be? AdvanceLab offers standard fume hoods with widths 3ft, 4ft, 5ft & 6ft, of course there are many options in between and the factory can flexibly customize the size based on request.
  • Plus, will there be equipment enclosed in the hood? If the answer is yes, then what are the dimensions of the equipment? This information is essential to determining how deep the hood needs to be to house your equipment.
  • Do you need a bench-top or floor mounted hood? Applications that use extra-large equipment, such as 50-gallon drums, or applications that require equipment to be wheeled into the hood via a cart would require a Walk-in Fume Hood.

3. Do you require service fixtures or other accessories in the fume hood?

These include (but are not limited to) airflow monitors, electrical outlets, compressed air, laboratory gas, vacuum and cold water fixtures. Gooseneck faucets are also available. Finally, do the fixtures need to be factory installed, or will the installer handle that at the job site by using field-installed kits?

4. What about required accessories outside of the fume hood?

  • Do you need a work surface and base cabinets, or will you be using existing casework to support the hood?
  • If you do need base cabinets, do you need acid storage, solvent storage or non-chemical storage?
  • Do you need ductwork from the hood to the roof, or will your HVAC contractor provide it?
  • Do you need a Wet Scrubber to treat the acid/ base fume before releasing them to environment?

5. How will the fume hood be exhausted?

Every fume hood needs an Exhaust Fan (blower), and it is often misconceived that a blower comes attached to a fume hood. Will there be a dedicated blower for this hood, or will it connect to a central exhaust system? If it connects to a central system, will it be constant volume or variable air volume?

6. Do you need a built-in blower or a remotely located blower?

Built-in blowers are easier to install (and therefore less expensive), but they can be noisy and they put the ductwork under positive pressure, so they should be reserved for non-hazardous applications, short duct runs and instances where a remote blower cannot be installed (such as a mobile lab).

Remote blowers, though more complex to install, can be sized for the specific situation and keep the ductwork under negative pressure for safer operation.

7. What is the layout of the duct run?

Will the duct go directly to the roof, or does it need to make some turns before reaching the roof? What diameter of duct will be used? Once the duct penetrates the roof, a final 90-degree elbow will be needed to turn the duct horizontal, then three to five feet of straight duct is needed between the elbow and blower.

Finally, the exhaust stack should include a zero-pressure weathercap to prevent rain, and should terminate at least 10 feet above the roofline to allow the fumes to reach the airstream and not be returned into the building’s air handling equipment.

Of course, there will be other specified factors to choose fume hood depending on user's requirement, but make sure you think of all elements above and contact us for further help.