Ducted vs Ductless Fume Cupboard: Which Is Safe for You?
Updated: Sep 28
Choose a ducted fume cupboard for varied, high-volume or unpredictable chemistry, and a ductless fume cupboard for a known set of chemicals in modest amounts where you can't do building work. Both protect you by drawing air away from you across the work surface.
Ducted fume cupboard | Ductless fume cupboard | |
|---|---|---|
Where the air goes | Discharged outside | Carbon-filtered, returned to the room |
Chemicals | Effectively unlimited | A defined list, at defined quantities |
Perchloric, HF, high-volume solvent | Yes, if specified correctly | No |
Building work | Ducting, fan, roof or wall penetration | None |
Mobility | Fixed | Portable |
Running cost | Heated air lost continuously | Carbon filter changes |
Lead time | Weeks plus contractors | Days |
The short version
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Fume cupboard, biosafety or laminar flow? match the hazard
Use a fume cupboard for chemicals, a biosafety cabinet for biological agents, and a laminar flow cabinet only to protect a sterile sample, never the operator.
Fume cupboard | Biosafety cabinet | Laminar flow cabinet | |
|---|---|---|---|
Protects operator | Yes, from chemicals | Yes, from biological agents | No |
Protects sample | No | Yes | Yes |
Right for | Solvents, acids, powders, digestion | Cell culture, clinical microbiology | Media pouring, sterile assembly |
Wrong for | Anything infectious | Volatile toxic chemicals | Any hazard to the operator |
“ A laminar flow cabinet blows filtered air straight past the operator. Using one for solvent work aims the hazard at your face. — LS Scientific |
Compare sterile options in our laminar flow cabinet guide.
Ductless fume cupboards: how they work
A ductless fume cupboard pulls air across the work, through a pre-filter and an activated carbon filter, and returns it clean to the room. Three things decide whether it's safe for you:
Filter chemistry must match your compounds. Standard carbon handles organic solvents; impregnated carbons handle acids, ammonia, formaldehyde or mercury.
Loading must stay within capacity. Occasional milligram work is very different from decanting litres daily.
Breakthrough must be managed. Carbon saturates silently, so filter monitoring and a change schedule are essential.
If you can't list your compounds and quantities, you can't specify a ductless cabinet. The honest answer is a ducted fume cupboard.
Price: the ductless fume cabinet we stock
Our ductless fume cabinet, the Chemcap Clearview, costs £3,945.
Ductless fume cabinet (Chemcap Clearview) | £3,945 |
Face velocity | 0.5 m/s |
Size (W × D × H) | 1000 × 570 × 1145 mm |
Noise | < 50 dB(A) |
Chemcap Clearview ductless fume cabinet: pre-filter, MP carbon filter and LED lighting. £3,944.85
Audible low-airflow alarm so you know when a loaded filter drops the face velocity.
Safe-change pre-filter, baggable under negative pressure.
Service-due indicator and lockable front doors.
Fully portable: no ducting, no contractor, ideal for leased buildings.
Need a ducted fume cupboard? We supply them to specification. Bring your compounds and quantities, the width you need, the nearest external wall or roof void, and whether the building is leased.
Accessories: LabJaws fume hood lab frames, 965 mm £1,026.00, 1,270 mm £1,111.50, 1,575 mm £1,187.50, 2,184 mm £1,372.75. For Kjeldahl digestion, the Velp JP fume aspiration pump.
After purchase: safe use and COSHH testing
Work at least 150 mm inside the cupboard with the sash at or below the marked height, keep it clear of stored bottles, and have it tested at least every 14 months under COSHH.
Work at least 150 mm inside the front, with the sash at or below the marked height.
Don't store bottles inside. Clutter at the back disrupts airflow.
Raise bulky equipment on blocks so air can flow underneath.
Test regularly (at least every 14 months under COSHH) and keep the records.
Ductless: change carbon filters on schedule and log it.
FAQ: fume cupboards
What is a fume cupboard?
A ventilated enclosure that draws air away from the operator across the work surface, capturing vapours, gases and dusts and either discharging them outside or filtering them.
What is the difference between a ducted and ductless fume cupboard?
A ducted fume cupboard discharges air outside and handles almost any chemistry. A ductless fume cupboard filters air through carbon and returns it to the room, for a defined list of compounds.
Is a fume cabinet the same as a fume cupboard?
Yes. Fume cupboard, fume hood and fume cabinet describe the same equipment.
Can a ductless fume cupboard handle acids?
Some can, with an impregnated carbon filter matched to the acid. Perchloric and hydrofluoric acid need a specially specified ducted fume cupboard.
How often must a fume cupboard be tested?
Under COSHH, local exhaust ventilation must be thoroughly examined and tested at least every 14 months, with records kept.
How much does a fume cupboard cost?
Our ductless fume cabinet is £3,944.85. Ducted fume cupboards are quoted to specification because ducting, fan and installation often cost more than the cupboard.
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