How to Fix Smoke in a Restaurant Kitchen

Smoke in a restaurant kitchen is a sign that the exhaust system is not keeping up. This guide explains why it happens, what to check first, and what to do if the system is clean and smoke still escapes.

Why does a restaurant kitchen fill with smoke?

Smoke should be captured by the hood and carried out through the filters, the duct and the fan. When any part of that path is blocked, weak or poorly matched to the cooking line, smoke stays in the kitchen and drifts into the dining area.

What to check first

1. The filters. Clogged or damaged grease filters cut airflow. Clean them, and replace any that are bent or no longer seat tightly (exhaust filter cleaning).
2. The hood and the grease cups. A greasy canopy and full grease cups make the hood less effective. Our guide to how to clean a commercial kitchen hood has the steps.
3. The duct. Grease on the duct walls narrows the path and slows the air. It needs machinery to clean properly (exhaust duct cleaning).
4. The fan. Grease on the blades unbalances the fan and strains the motor, so extraction gets weaker. Signs are noise, vibration and grease on or around the fan (restaurant exhaust fan cleaning).
5. The smoke and odour stages. If the kitchen has an ESP or ecology unit, a loaded collector lets smoke and grease particles through. Read what an ecology unit is.

If the system is clean and smoke still escapes

Cleaning fixes most smoke problems, but not all of them. If the system is clean and smoke still escapes, ask a ventilation engineer to check these:

• Replacement air: an extraction system needs air coming in to replace what it removes, and in a tight space without it the exhaust cannot work properly
• Hood capture: smoke escapes at the edges if the hood does not cover the cooking line, for example after equipment has been moved or added
• Cross-drafts: doors, windows or air-conditioning blowing across the cooking line can push smoke out of the hood's reach
• Airflow: an engineer can measure how much air the system really moves

What a professional cleaning does for smoke

A full cleaning removes the grease that blocks the path, so air moves the way the system was designed to. We inspect first and recommend only what the system needs. Our complete exhaust system cleaning covers the hood, filters, duct, ESP or ecology unit where fitted, and the fan in one visit, and every job ends with a company-attested report that includes before and after photos and recommendations. To plan the schedule, read how often to clean a commercial kitchen exhaust.

Smoke problem in your restaurant? Contact HoodEx and we will arrange an inspection. We work day and night shifts, so a visit can be arranged outside your trading hours.

Frequently asked questions