Recirculating Fume Hood

A Recirculating Fume Hood—also called a ductless fume hood—is a self-contained ventilated enclosure that pulls contaminated air through filters and returns the cleaned air to the laboratory, rather than ducting it outside.

How Recirculating Fume Hood works

1. Air is drawn in through the front sash opening.

2. A pre-filter captures larger dust and particulates.

3. The main filter—typically activated carbon for vapours/gases and/or HEPA for particles—removes the targeted contaminants.

4. A fan returns the filtered air to the room.

5. Best-fit applications

   Recirculating hoods are generally suitable for low-volume, low-toxicity work where the exact chemical exposure is known and matched to the filter type—for example:

   • Weighing or dispensing small quantities of powders.

   • Light solvent handling with appropriate carbon filtration.

   • Pharmaceutical, cosmetic, or analytical sample preparation.

   • Educational and small QC laboratories

   • Applications where ducting is impractical.