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Extraction cleaning - energy
A greasy extractor fan does not just move less air - it draws more power to do it, every hour the kitchen runs. A clogged fan is a steady, hidden energy cost that a clean removes.
The short answer
Grease building up on an extractor fan's blades and housing unbalances it and makes it less efficient, so it draws more electrical power while actually moving less air. That efficiency loss runs continuously - every hour the extraction is on - so a clogged fan is a steady, hidden addition to the energy bill. Cleaning the fan restores its efficiency, cutting the power it draws and the cost that goes with it.
What grease does to a fan
An extractor fan sits at the greasiest point of the system, pulling grease-laden air through itself continuously, so grease steadily coats its blades and housing. That coating does several things at once: it adds weight and throws the fan out of balance, it changes the shape of the blades so they move air less efficiently, and it makes the whole assembly work harder to spin. A grease-caked fan is a fan fighting its own build-up.
The result is a fan that is both less effective and less efficient. It moves less air than it should because the fouled blades cannot grip the air properly, and it draws more power to do even that, because the motor is working against the imbalance and drag the grease creates. Both effects come from the same cause, and both cost - one in performance, the other in energy.
Why it costs energy
The energy cost comes from the motor having to work harder. A balanced, clean fan moves air efficiently, drawing the power its design intends. A grease-laden one, unbalanced and dragged down by its coating, forces the motor to draw more current to keep turning - and if the extraction is struggling to clear the kitchen, it may be run harder or longer to compensate, drawing still more. The fan is spending more electricity to deliver less extraction.
That is the worst kind of energy cost: paying more to get less. Every unit of extra power the clogged fan draws is wasted on overcoming its own grease rather than moving air, and none of it improves the extraction. It is pure inefficiency, converted directly into a higher electricity bill for a worse result.
Why it adds up
The reason a clogged fan's energy cost matters is time. The extraction runs whenever the kitchen is cooking - long hours, every trading day - so the efficiency loss from a grease-laden fan is not an occasional hit but a continuous one. A small extra draw, running every hour of every service, compounds into a meaningful annual cost that never shows itself as a distinct line, just a slightly higher bill.
Because it is continuous and invisible, it accumulates untouched. Nobody sees the fan drawing more than it should, the electricity bill creeps up without an obvious cause, and the connection between the greasy fan and the higher energy cost is never made. The clogged fan quietly taxes every hour of extraction until something prompts a clean.
Cleaning restores efficiency
Cleaning the fan reverses the problem directly. Removing the grease from the blades and housing rebalances the fan, restores the blade shape so it moves air efficiently again, and takes the drag off the motor - so it draws the power it was designed to, not more. The extraction improves and the energy draw falls at the same time, because both were being hurt by the same grease.
This is why fan cleaning pays back on energy as well as fire safety and performance. A clean fan moves more air on less power than a clogged one, so the clean that removes the fire risk and restores the extraction also cuts the running cost. For a component that runs continuously, keeping it clean is a genuine and recurring energy saving, not just a compliance measure.
The takeaway
The useful way to see a clogged extractor fan is as a running cost, not just a dirty component. It draws more power for less air every hour the kitchen is open, quietly inflating the energy bill for a worse result - and unlike a one-off, it does so continuously until it is cleaned. That makes the energy angle a real, if hidden, reason to keep the fan clean, alongside the fire and performance reasons.
So when a proper extract clean reaches and cleans the fan, it is not only removing a fire risk and restoring the extraction - it is taking a steady energy penalty off the bill. A clean fan is a cheaper fan to run, which is one more way that keeping the extraction clean pays for itself rather than simply costing money.
Questions
Yes. Grease on the blades and housing unbalances the fan and makes it less efficient, so it draws more power while moving less air. That efficiency loss runs continuously while the kitchen is open, quietly inflating the energy bill.
It adds weight and unbalances the fan, changes the blade shape so it moves air less efficiently, and creates drag - so the motor works harder and draws more current to keep turning, delivering less extraction for more energy.
Because the extraction runs whenever the kitchen cooks - long hours, every day. A small extra draw running continuously compounds into a meaningful annual cost that shows only as a slightly higher bill, with no obvious cause.
Yes. Removing the grease rebalances the fan, restores its efficiency and takes the drag off the motor, so it draws the power it was designed to. The extraction improves and the energy draw falls together.
It is an additional reason to clean the fan. Cleaning removes the fire risk and restores performance and cuts the energy penalty at once - all hurt by the same grease, all fixed by the same clean.
In a proper whole-system clean, yes - the fan is cleaned along with the canopy, filters and ductwork, precisely because it is where grease does the most damage to performance, energy and safety.
We clean and rebalance the extract fan so it moves more air on less power - cutting the energy penalty a grease-clogged fan carries.
