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Kitchen extraction cleaning - heat
If your kitchen has grown hotter and more uncomfortable, your extraction may be part of the reason. A greasy, grease-choked system pulls less air, so it removes less of the heat the cooking produces - leaving the kitchen hotter. Here is why a greasy extraction makes your kitchen hotter, and why cleaning it helps cool things down. This is general guidance.
The short answer
Commercial kitchens are hot places - but if yours has got noticeably hotter, or is hotter than it should be, a greasy extraction system may be part of the reason. The link runs through the airflow. Here's why a greasy extraction makes your kitchen hotter, and why cleaning helps. This is general guidance. The extraction removes heat. One of the jobs of the kitchen extraction - alongside removing smoke, steam and grease - is to remove heat. The cooking produces a lot of heat: from the hot appliances, and from the hot air, steam and gases rising off the cooking. The extraction draws that hot air up into the canopy and away, carrying the heat out of the kitchen - which helps keep the kitchen from overheating. So the extraction is part of how the kitchen stays (relatively) bearable to work in: it takes the cooking heat away. Heat removal depends on airflow. How much heat the extraction removes depends on how much air it moves. The system removes heat by drawing out the hot air - so the more air it moves, the more hot air (and heat) it carries away; the less air it moves, the less heat it removes. So the extraction's heat-removal depends directly on its airflow (the volume of air it's moving). A greasy system moves less air. This is where grease comes in. A greasy extraction system moves less air, because grease build-up chokes the airflow. Grease accumulating in the filters, ductwork and on the fan narrows the airflow path and loads the fan - raising the resistance and cutting the volume of air the fan can move (the same reason a greasy system extracts smoke and grease poorly, with weak capture at the canopy). So a grease-choked system pulls less air than a clean one. Less air means less heat removed. Putting it together: a greasy system moves less air, and moving less air means removing less heat. So a greasy extraction removes less of the cooking heat than a clean one would - which means more of that heat stays in the kitchen. The result is a hotter, more uncomfortable kitchen: the extraction that should be carrying the heat away is under-performing, so the heat builds up. So a greasy extraction system makes your kitchen hotter, by pulling less air and therefore removing less heat. Cleaning cools it down. The flip side is the fix: cleaning the extraction restores the airflow, so it removes more heat again. A proper clean removes the grease that's choking the airflow (in the filters, ductwork and fan) - so the system moves more air again, removing more of the cooking heat and helping cool the kitchen back down. So if a greasy extraction has been making your kitchen hotter, cleaning it can help bring the temperature back down (by restoring the heat removal). Keep it in context. A greasy extraction is one factor in kitchen heat, not the only one. Other factors include the weather (a hot day or heatwave), the cooking load (busy, intense cooking produces more heat), the make-up air and ventilation design, and any air conditioning. So cleaning the extraction helps with the part it's responsible for (restoring the heat removal), but persistent heat problems may also involve these other factors - and issues with ventilation design, make-up air or air conditioning are matters for a ventilation specialist. Still, a greasy extraction is a real, cleanable contributor to a hotter kitchen. The takeaway. So a greasy extraction system makes your kitchen hotter because it pulls less air (the grease choking the airflow), so it removes less of the cooking heat - leaving more heat in the kitchen. Cleaning it restores the airflow and the heat removal, helping cool the kitchen down. So if your kitchen has got hotter, clean the extraction to restore its heat removal. This is general guidance.
Key points
The extraction removes heat
One of the jobs of the kitchen extraction - alongside removing smoke, steam and grease - is to remove heat. The cooking produces a lot of heat: from the hot appliances, and from the hot air, steam and gases rising off the cooking. The extraction draws that hot air up into the canopy and away, carrying the heat out of the kitchen - which helps keep the kitchen from overheating.
So the extraction is part of how the kitchen stays bearable to work in: it takes the cooking heat away, along with the smoke and grease. A well-functioning extraction removes a good deal of the cooking heat, helping keep the temperature down; without it (or with it under-performing), that heat would stay in the kitchen. This heat-removal role is often under-appreciated (people think of extraction as being about smoke and grease), but it's a real and important function - especially in a hot kitchen. So the extraction removes heat - it carries the cooking heat away - is the starting point: the extraction is part of your kitchen's heat management, and how well it does that depends on its airflow (covered next). So the extraction takes the cooking heat away, if it's working well. This is general guidance.
Heat removal needs airflow
How much heat the extraction removes depends on how much air it moves. The system removes heat by drawing out the hot air - so the more air it moves, the more hot air (and heat) it carries away; the less air it moves, the less heat it removes. So the extraction's heat-removal depends directly on its airflow: the volume of air it's actually moving.
This is the key link: heat removal is a function of airflow. A system moving a good volume of air removes a lot of heat (carrying away lots of hot air); a system moving little air removes little heat. So anything that reduces the airflow reduces the heat removal - which is exactly what grease does (covered next). This is why the state of the extraction affects the kitchen's temperature: a well-performing system (good airflow) removes heat well and keeps the kitchen cooler; an under-performing one (poor airflow) removes less heat and leaves the kitchen hotter. So heat removal needs airflow - more air moved, more heat carried away - is the mechanism connecting the extraction's performance to the kitchen's heat: the airflow drives the heat removal. So the more air the system moves, the more heat it removes. This is general guidance.
Grease chokes the airflow
This is where grease comes in: a greasy extraction system moves less air, because grease build-up chokes the airflow. Grease accumulating in the filters, ductwork and on the fan narrows the airflow path and loads the fan - raising the resistance and cutting the volume of air the fan can move. So a grease-choked system pulls less air than a clean one.
This is the same mechanism that makes a greasy system extract smoke and grease poorly (weak capture at the canopy, smoke escaping): the choked airflow. The grease that builds up in a neglected system reduces the airflow across the board - so the system moves less air, which shows up as weak capture (smoke and grease not drawn away) and, as this page highlights, as reduced heat removal (less hot air drawn away). So the grease has a single effect (choking the airflow) with multiple consequences, heat being one of them. So grease chokes the airflow - a greasy system moves less air - is the crucial step: the grease reduces the airflow, so the system moves less air and (as the next section covers) removes less heat. So a greasy system's choked airflow means it moves less air. This is general guidance.
Less air, less heat removed
Putting it together: a greasy system moves less air, and moving less air means removing less heat. So a greasy extraction removes less of the cooking heat than a clean one would - which means more of that heat stays in the kitchen. The result is a hotter, more uncomfortable kitchen: the extraction that should be carrying the heat away is under-performing, so the heat builds up.
So the chain is clear: grease chokes the airflow, the choked system moves less air, moving less air removes less heat, and less heat removed means a hotter kitchen. A greasy extraction system therefore makes your kitchen hotter - not by adding heat, but by failing to remove it. This is why a kitchen with a neglected, greasy extraction can feel hotter than it should: the system isn't carrying the heat away as it would if it were clean. So if your kitchen has got hotter (beyond what the weather and cooking load explain), a greasy, under-performing extraction may be part of the reason. So less air, less heat removed - so the kitchen gets hotter - is the conclusion: the greasy extraction leaves more heat in the kitchen by removing less of it. The fix is cleaning (covered next). So a greasy extraction leaves the kitchen hotter by removing less heat. This is general guidance.
Cleaning cools it down
The flip side is the fix: cleaning the extraction restores the airflow, so it removes more heat again. A proper clean removes the grease that's choking the airflow (in the filters, ductwork and fan) - so the system moves more air again, removing more of the cooking heat and helping cool the kitchen back down. So if a greasy extraction has been making your kitchen hotter, cleaning it can help bring the temperature back down, by restoring the heat removal.
Keep it in context, though: a greasy extraction is one factor in kitchen heat, not the only one. Other factors include the weather (a hot day or heatwave), the cooking load (busy, intense cooking produces more heat), the make-up air and ventilation design, and any air conditioning. So cleaning the extraction helps with the part it's responsible for (restoring the heat removal), but persistent heat problems may also involve these other factors - and issues with ventilation design, make-up air or air conditioning are matters for a ventilation specialist (as covered in the ventilation-and-kitchen-heat-what-operators-get-wrong page). Still, a greasy extraction is a real, cleanable contributor to a hotter kitchen - so cleaning it is a worthwhile step if your kitchen has got hotter. So cleaning cools it down - restore the airflow, restore the heat removal - is the takeaway: clean the greasy extraction to restore its airflow and heat removal, helping cool the kitchen, alongside addressing the other heat factors. So clean the system to bring back the heat removal and cool the kitchen. This is general guidance.
Questions
Yes - the extraction removes heat by drawing out hot air, and a greasy, grease-choked system moves less air, so it removes less heat, leaving more of it in the kitchen; cleaning restores the airflow and the heat removal. Yes - a greasy extraction can make your kitchen hotter. One of the extraction's jobs is to remove heat: it draws the hot air (from the cooking and appliances) up and away, carrying the heat out of the kitchen. How much heat it removes depends on how much air it moves. A greasy system moves less air, because grease build-up (in the filters, ductwork and on the fan) chokes the airflow - narrowing the path and loading the fan, so it pulls less air. Moving less air means removing less heat - so a greasy extraction removes less of the cooking heat, leaving more of it in the kitchen and making the kitchen hotter. So a greasy extraction makes your kitchen hotter by pulling less air and removing less heat. The fix is cleaning: removing the grease restores the airflow, so the system removes more heat again and helps cool the kitchen. So yes - a greasy system removes less heat, leaving the kitchen hotter. So yes; it chokes the airflow and removes less heat. This is general guidance.
It removes heat by drawing hot air out of the kitchen - so a well-performing extraction (good airflow) removes lots of heat and keeps the kitchen cooler, while an under-performing one (poor airflow) removes less and leaves it hotter. The extraction affects kitchen temperature by removing heat - drawing the hot air (from the cooking and hot appliances) up into the canopy and away, carrying the heat out of the kitchen. So it's part of how the kitchen stays bearable to work in. How much heat it removes depends on how much air it moves: the more air, the more hot air (and heat) carried away; the less air, the less heat removed. So a well-performing extraction (moving a good volume of air) removes a lot of heat and helps keep the kitchen cooler, while an under-performing one (moving little air, e.g. from grease choking it) removes less heat and leaves the kitchen hotter. So the extraction's state directly affects the kitchen temperature through its airflow and heat removal. This is why a greasy, under-performing extraction can leave a kitchen hotter, and why cleaning it (restoring the airflow) helps cool it. So it removes heat via airflow - more airflow, cooler kitchen. So by drawing heat out; its airflow determines how much. This is general guidance.
It helps - cleaning removes the grease choking the airflow, so the system moves more air and removes more heat, cooling the kitchen; but heat also depends on the weather, cooking load and ventilation/air conditioning, so cleaning addresses one factor. Cleaning the extraction will help cool your kitchen, by restoring the part of the cooling the extraction is responsible for. A proper clean removes the grease that's choking the airflow (in the filters, ductwork and fan), so the system moves more air again - removing more of the cooking heat and helping bring the temperature down. So if a greasy extraction has been making your kitchen hotter (by removing less heat), cleaning it can help. However, cleaning addresses one factor among several: kitchen heat also depends on the weather (a hot day or heatwave), the cooking load (busy cooking produces more heat), the make-up air and ventilation design, and any air conditioning. So cleaning the extraction helps with its part (restoring the heat removal), but persistent heat problems may also involve these other factors (issues with ventilation design, make-up air or air conditioning being matters for a ventilation specialist). Still, cleaning a greasy extraction is a worthwhile, real step toward a cooler kitchen. So yes, it helps - as one factor among several. So it helps by restoring the heat removal. This is general guidance.
Because grease chokes the airflow - narrowing the path and loading the fan, so the system moves less air; and since heat removal depends on how much air is moved, less air means less heat carried away. Grease reduces the extraction's heat removal because it chokes the airflow, and heat removal depends on airflow. As grease builds up in the filters, ductwork and on the fan, it narrows the airflow path and loads the fan - raising the resistance and cutting the volume of air the fan can move. So a greasy system moves less air than a clean one. And because the extraction removes heat by drawing out the hot air, the amount of heat it removes depends on the amount of air it moves - so a system moving less air (choked by grease) removes less heat. So the grease's effect on the airflow (choking it) directly reduces the heat removal (less air carried away means less heat carried away). This is the same choked airflow that makes a greasy system extract smoke and grease poorly (weak capture) - the reduced heat removal is another consequence of the same airflow reduction. So grease reduces heat removal by choking the airflow that carries the heat away. So because it cuts the airflow, and heat removal needs airflow. So it chokes the airflow, so less heat is removed. This is general guidance.
The weather (hot days, heatwaves), the cooking load (busy, intense cooking produces more heat), the make-up air and ventilation design, and any air conditioning; a greasy extraction is one cleanable factor among these. Besides a greasy extraction removing less heat, a kitchen's temperature depends on several other factors. The weather: a hot day or heatwave raises the ambient temperature and the kitchen with it. The cooking load: busy, intense cooking (lots of appliances running hard) produces more heat, making the kitchen hotter regardless of the extraction. The make-up air and ventilation design: how fresh/cool air is brought into the kitchen and how the ventilation is designed affects the temperature (inadequate make-up air or poor design can leave it hotter). And any air conditioning: whether the kitchen has cooling, and whether it's working and adequate. So a greasy extraction is one factor among several - a real, cleanable one (cleaning it restores its heat removal), but not the only one. Persistent heat problems may involve the weather, the cooking load, the ventilation design/make-up air, or the air conditioning - the latter being matters for a ventilation specialist. So cleaning the extraction helps with its part; the other factors matter too. So weather, cooking load, ventilation design and air conditioning. So several factors, of which a greasy extraction is one. This is general guidance.
It can be - if the kitchen has got hotter beyond what the weather and cooking explain, a greasy, under-performing extraction (removing less heat) may be part of the cause, so it's worth having the system checked and cleaned. A hotter kitchen can be a sign your extraction needs cleaning, though it's not the only possible cause. If your kitchen has got noticeably hotter - beyond what the weather (a hot spell) and the cooking load (a busy period) would explain - then a greasy, under-performing extraction may be part of the reason: a grease-choked system moves less air and removes less heat, leaving the kitchen hotter. This often comes with other signs of a greasy system (weak capture at the canopy, smoke lingering, a louder fan), which together point to a system needing cleaning. So a persistently hotter kitchen is worth investigating, and having the extraction checked and cleaned is a sensible step (it restores the airflow and heat removal). That said, also consider the other heat factors (weather, cooking load, ventilation/air conditioning) - the extraction is one part. But if the system is greasy or overdue a clean, cleaning it can help cool the kitchen. So it can be - have the system checked and cleaned. So possibly - worth checking and cleaning the extraction. This is general guidance.
A greasy extraction removes less heat, leaving your kitchen hotter; we clean the whole system to TR19 Grease, restoring the airflow so it moves more air and carries more of the cooking heat away - helping cool the kitchen, as well as controlling the fire risk. Ask us to clean your extraction and restore its heat removal. This is general guidance.
