Technical Foundation
What Is a Ductless Fume Hood?
A ductless fume hood draws contaminated air through a filter cartridge that adsorbs or captures the hazard, then recirculates the cleaned air back into the room — unlike a ducted fume hood, which exhausts continuously to the outside. Because there's no outside exhaust, filter selection has to match the specific chemical or particulate hazard being worked with; a single activated carbon filter will not capture particulates, and a HEPA filter will not adsorb volatile organic vapors.
Filter capacity is finite and consumed over time — carbon filters saturate and stop adsorbing once their chemical capacity is used up, which is why ductless hoods are only appropriate for low-volume, low-concentration work with chemicals on the filter manufacturer's approved list, not for high-volume or highly toxic work where a ducted hood or biosafety cabinet is required. Face velocity (airflow across the sash opening) determines containment performance and is typically specified to ASHRAE 110 test standards.
Prefer a quick quote?
Get Ductless Fume Hoods Pricing in Your Inbox
Skip the search — tell us the sash width, contaminant/chemical type and filter media needed and we will come back with pricing.
| Spec | What It Means | Why It Matters |
|---|---|---|
| Filter Type | Activated carbon, HEPA, combination | Carbon adsorbs vapors/odors; HEPA captures particulates — chemical filters don't do both |
| Face Velocity | Typically 80-120 FPM at the sash opening | Determines containment performance, tested per ASHRAE 110 methodology |
| Sash Width | 18in to 72in+ work openings | Sized to the equipment and hands-on work area needed inside the hood |
| Chemical Compatibility List | Manufacturer-published approved chemical list per filter | Only chemicals on the approved list are safely captured — using unlisted chemicals risks breakthrough |
| Filter Saturation Monitoring | Photoionization detector (PID) or scheduled replacement | PID monitoring detects breakthrough in real time versus relying on a fixed replacement schedule |
Shop Ductless Fume Hoods
Browse Ductless Fume Hoods Sub-Categories
Organised by filter media and application. Pick a sub-category, or describe the chemicals and airflow needed and let ChatMRO match the hood.
How it works
From Half-Remembered Part Number to PO, in Three Steps.
Ask
Type an MPN, paste a spec sheet, or describe the part in plain English. ChatMRO understands engineer-speak.
Compare
Side-by-side specs, cross-references, and equivalents from multiple sources — without the clutter of endless browser tabs.
Quote & Buy
Request a quote or add to cart. Volume discounts, VAT-aware pricing, and consolidated procurement — all in one place.
Applications
Where Ductless Fume Hoods Get Used
Ductless fume hoods are specified anywhere low-volume chemical work needs vapor or particulate containment without ducted exhaust infrastructure.
Teaching & Academic Laboratories
Low-volume student chemistry work where ductwork retrofits into an existing building aren't feasible.
Histology & Pathology Labs
Formaldehyde and xylene handling during tissue processing, using filters specifically rated for those compounds.
Quality Control & Testing Labs
Small-scale sample prep and solvent handling in QC labs without dedicated exhaust infrastructure.
Pharmaceutical R&D
Bench-scale compounding and analysis work in labs where installing ducted exhaust isn't practical.
Cannabis & Botanical Extraction Testing
Solvent-based extraction analysis requiring vapor containment in facilities without ducted fume hood infrastructure.
Mobile & Temporary Lab Setups
Portable fume containment for field labs, satellite testing sites, or temporary lab buildouts.
FAQ
Ductless Fume Hoods Questions, Answered
How is a ductless fume hood different from a ducted fume hood?
A ducted fume hood continuously exhausts contaminated air outside the building through ductwork, giving essentially unlimited capacity for the duration of use. A ductless hood filters and recirculates air back into the room, which limits it to chemicals and volumes within the filter's finite adsorption capacity — it's a lower-cost, easier-to-install option for appropriate low-volume applications, not a universal substitute.
How do I know which filter to use for my chemicals?
Manufacturers publish an approved chemical list for each filter type, specifying which compounds the carbon media effectively adsorbs and at what typical capacity. Always check your specific chemicals against the filter's approved list before use — a chemical not on the list may pass through unfiltered, and mixing incompatible chemicals in front of the same filter can also reduce its effectiveness.
How do I know when to replace the filter?
Some ductless hoods include a photoionization detector (PID) or gas sensor that monitors for breakthrough in real time and alerts before saturation. Without active monitoring, filters should be replaced on a schedule calculated from usage volume, chemical concentration, and the filter's published capacity — following the manufacturer's saturation calculation rather than guessing.
What face velocity should a ductless fume hood maintain?
Most ductless hoods are designed to maintain roughly 80-120 feet per minute face velocity at the sash opening, tested to ASHRAE 110 containment standards similar to ducted hoods. Face velocity that's too low risks contaminant escape past the sash; too high can create turbulence that pulls contaminants back into the room.
Are ductless fume hoods approved for high-hazard or high-volume chemical work?
No — ductless hoods are intended for low-volume, low-concentration work with chemicals confirmed on the filter's approved list. High-hazard, high-volume, or unlisted chemical work requires a ducted fume hood with continuous outside exhaust, or in biological contexts, a certified biosafety cabinet, which isn't the same as a chemical fume hood.
Keep browsing
Related Categories
Explore More
- Grate Magnets Housings
- Planes and Shaving Tools
- Indoor Air Quality Sampling Pump Accessories
- Black Pipe Nipple Assortments
- Wall Protection Accessories
- Wireless Push Buttons
- Kitchenware Tumblers, Bowls and Shakers
- Hole Cutters
- Ergonomic Workbenches
- Key Stock Assortments
- Door Louvers
- Digital and Mechanical Timers
Find Your Next Part Now.
Describe a part number, spec or what it does.