Guide
Commercial kitchen extraction and ventilation: the real cost driver
Updated
The canopy over the cooking line is the visible five per cent. The rest of the system is the part that decides whether your unit works at all.
What a kitchen ventilation system actually is
A commercial kitchen ventilation system is four things working together: extraction over the cooking line, a duct route to a discharge point, treatment of what comes out, and enough replacement air coming in. Get any one wrong and the others fail. Under-supplied make-up air is the classic example: the extract cannot pull, doors become hard to open, and the kitchen fills with heat while the fan runs at full speed.
Kitchen ventilation in the UK is designed to a recognised industry specification, and a competent supplier will name it, design to it and hand over the calculations. If a quote has no design behind it, you are not buying a system, you are buying parts.
Where the cost lives
- The duct route
- Distance, bends, riser access and whether the route crosses other tenancies. A short route to a rear elevation is cheap; a run to roof level through a shared riser in an occupied building is not.
- The discharge point
- Usually at roof level and away from openings and neighbours. Landlord consent, planning and the physical practicality of getting there frequently decide the entire design.
- Odour control
- Carbon filtration, electrostatic precipitation or UV treatment, specified according to the risk and the sensitivity of the surroundings. Often a planning condition, and it brings a consumables and maintenance cost with it.
- Noise attenuation
- Attenuators, anti-vibration mounts and fan selection. Residential neighbours and licensing conditions make this non-negotiable in most town centre units.
- Make-up air
- Tempered replacement air, often the item value-engineered out of a cheap quote and the reason the kitchen is unbearable in August.
- Fire safety
- Fire stopping where the duct crosses compartments, dampers where required, and grease-tight construction with access panels for cleaning.
The costs that continue after the fit-out
- Duct and canopy cleaning on a regular cycle. Grease deposits in ductwork are a serious fire risk, and your insurer will very likely require documented cleaning at a stated frequency.
- Filter changes on the canopy and on any odour control system.
- Fan and system servicing, including belts, bearings and the interlock if you cook on gas.
- Records. Keep the certificates. They are what you show an insurer, an environmental health officer and a future buyer of the business.
Questions to ask before you accept an extraction price
- "What specification is this designed to, and will I get the design calculations?"
- "Where does it discharge, and who is obtaining consent for that route and location?"
- "What make-up air is included, and is it tempered?"
- "What odour and noise treatment is included, and what does it cost to run and maintain?"
- "Is fire stopping, damper provision and grease-tight ductwork with access panels included?"
- "If we cook on gas, is the gas interlock in this price or the gas package?"
- "What cleaning frequency will my insurer expect, and can you quote the ongoing contract?"
If the extract route on a unit you are considering is unresolved, resolve it before you sign the lease. It is the one problem in a kitchen fit-out that money alone cannot always fix.