Using Exhaust Hoods or Ducted Fume Hoods can lead to a variety of issues that affect the operation and safety of the fume hood. Below are a few common issues or concerns experienced with Exhaust Hoods.
• Ductwork particulate build-up resulting in downtime and costly maintenance procedures (Haugen, 2018)
• Safety concerns associated with ductwork build-up (Haugen, 2018)
• Issues servicing ducting due to particle build-up
• Reduced blower capacity due to build-up
• Hazardous residues left in ductwork
• Chemical fumes deteriorating ductwork structure (Haugen, 2018)
• Environmental concerns about contents of exhausted air
By adding filtration, you can help improve these conditions and reduce Exhaust Hood concerns. Our latest product – Exhaust Filter Box – makes adding filtration to any exhaust hood or ducted fume hood setup simple!
What is an Exhaust Filter Box?
An Exhaust Filter Box mounts on an existing exhaust hood and connects to the existing ductwork and fan system to provide particulate and/or chemical filtration. Depending on the application, the Exhaust Filter Box can be fitted with a HEPA/ASHRAE filter for particulate, Activated Carbon or Specialty-Blended Filter Media for chemical fumes, or a combination of both. The existing exhaust system draws fumes and particulate from under the hood into the filter box reducing the concentration of contaminants in the airflow. The filtered air exits through the unit’s plenum into existing ductwork and is released outside of the facility.
How Does an Exhaust Filter Box Work?
Benefits of an Exhaust Filter Box
• May reduce particle build-up in the ductwork
• May reduce /prevent costly maintenance and cleaning procedures
• Lessens the chance of safety concerns from ductwork build-up
• Mitigates chemical fumes lowering the amount released into the environment
• Aids in improving exhaust air sampling
Connection Options for the Exhaust Filter Box
• HEPA – up to 99.97% efficiency on particles 0.3 microns and larger
• ASHRAE – up to 95% efficiency on particles 0.5 microns and larger
• Activated Carbon
• Specialty-Blended Filter Media (i.e. acid gas, mercury, aldehyde, and ammonia)
Exhaust Filter Box Filter Configurations
Exhaust Filter Box Flow Rate Testing & Response Curve Graph
Our in-house testing department tested the Exhaust Filter Box with different filter combinations and varying motor speeds to provide an expected flow rate and pressure for each filter type. Five readings at different motor speeds were taken for each filter type and interpolated to create a trend line graph or response curve. This graph can be used to compare to your system’s fan curve to help predict the expected flow rate.
Exhaust Filter Box Applications*
*Please consult with your application specialist to see if your application would be a good fit for adding filtration.
Easily add filtration to your exhaust hood set-up with the Exhaust Filter Box!
Call today – 1.800.799.4609
Haugen, R. (2018). Common Fume Hood Containment Problems: Their Examination, Diagnoses, and Cures. Flow Sciences, Inc. Retrieved from https://flowsciences.com/common-fume-hood-containment-problems/.