Commercial Kitchen Extractor Fans

Commercial kitchen extract is not the same job as general ventilation. The air coming off a canopy is hot, humid and grease-laden, and that is hard on a fan. The specification question that matters more than airflow is how the fan protects its motor from what it is moving.

There are two answers, and we stock both. A bifurcated fan houses the motor outside the airstream in a separate compartment, with only the impeller in the duct, so the extracted air never passes over the windings. A high-temperature box fan keeps the motor within the casing but rates the whole unit for continuous duty at elevated temperature. Either way, a general purpose fan with an unprotected motor sitting in the middle of the airflow will not last in a kitchen.

We supply the Elta Qube and Slim Qube high-temperature box fans, rated to run continuously at 120°C, from 315mm to 710mm in AC and EC, single and three phase. Elta build these in the UK and position them as their kitchen ventilation range. Alongside them we stock the Elta Biflow bifurcated range from 250mm to 630mm in conical and cylindrical cases, and the Systemair KBT 160E4 Thermo Kitchen centrifugal fan for smaller 160mm duties.

If you are working from a canopy schedule or an extract rate, send it to hello@efans.co.uk or call 0161 399 3825 and we will match the duty rather than guess at it. Trade accounts get contract pricing and we can quote against a full schedule.

Commercial Extractor Fans | Commercial Box Fans | Cased Axial Fans | Fan Speed Controllers

What temperature does a commercial kitchen extract fan need to handle?

The Elta Qube and Slim Qube high-temperature ranges are built to withstand 120°C continuously, which covers commercial kitchen canopy extract. That is a different specification from smoke extract, where fans are tested to hold up at 300°C or 400°C for a defined period under EN 12101-3. If your project needs smoke extract as well as kitchen extract, they are two separate duties and usually two separate systems.

Bifurcated or high-temperature box fan?

Both keep the motor out of trouble, by different means. A bifurcated fan physically separates the motor into its own compartment outside the airstream, which suits in-line duct runs where you want the simplest possible protection from grease. A high-temperature box fan rates the whole assembly for hot air and adds acoustic lining, which suits installations where noise matters and where you want movable panels to change the discharge direction on site. For a straight duct run the Biflow is usually the simpler answer. For a plant room or anywhere noise is a concern, the Qube is usually better.

What size commercial kitchen extractor fan do I need?

Size on the canopy and the cooking duty, not the room. The extract rate is driven by the canopy face area and the appliances underneath it, because a bank of fryers and a grill puts out far more heat and grease than a prep area or a combi oven. Duct length and the number of bends then set the static pressure the fan has to work against. Send us the canopy dimensions and the appliance line and we will size it properly.

Single phase or three phase?

Single phase suits smaller kitchens and the lower end of the range. The Qube range now includes single phase EC models from 315mm to 560mm, which is useful on sites without a three phase supply. Above that, and across most of the Biflow range, fans are three phase. Check what is on site before specifying, because retrofitting a three phase supply is expensive and it is a common reason an order gets changed after delivery.

What about the ductwork?

The fan is only part of the specification. Grease-laden extract ductwork is covered by DW/172, the BESA Specification for Kitchen Ventilation Systems, which calls for stainless steel or fully welded mild steel. Galvanised steel is generally not suitable for grease extract because the joints can leak grease over time and it does not meet the fire rating criteria, though it is acceptable for supply air and non-greasy steam extract. Plastic ducting has no place in a commercial kitchen extract run, whatever it is fine for in a domestic kitchen.

Can the fan be speed controlled?

Yes, and on a commercial kitchen it is usually worth it. Running at full duty through a quiet afternoon wastes energy and makes the kitchen noisier than it needs to be. EC models give fully variable speed through a 0-10V signal or a potentiometer. AC models run on stepped speed control or an inverter. Check the controller is matched to the motor type before ordering, because AC and EC need different control. Our fan speed controllers list the compatible motor type on each product.

How long should a commercial kitchen extractor fan last?

Eight to fifteen years is a reasonable expectation for a correctly specified fan that is cleaned and serviced. The variables that shorten it are grease build-up, running the fan beyond its duty point, and neglected filters. Regular canopy filter cleaning does more for fan life than anything else.

Do you supply commercial kitchen fans for trade and project work?

Yes. We supply catering equipment installers, M&E contractors and facilities managers, and we hold stock across both ranges for next day delivery. If you have a multi-site rollout or a schedule to price, call 0161 399 3825 or email hello@efans.co.uk and we will quote the lot.