A kitchen hood keeps heat, smoke, steam, and grease from getting into your cooking area. But grease doesn’t just stop at the filters. It also sticks to the underside of the hood, the plenum entry, the ductwork, and the exhaust fan, where you can’t see it every day. That’s why cleaning with just filters typically brings back the same problems quickly: insufficient extraction, cooking smells that won’t go away, smoke haze during busy service, and greasy residue that comes back on neighbouring surfaces. As the build-up builds, ventilation decreases and the risk of fire rises because grease acts as a fuel load inside the system, as stated in the kitchen fire safety guidelines published by Fire & Rescue NSW.
This article tells you what you may safely clean and reach without putting yourself in danger, as well as the precautions you can take to keep your hood surfaces and parts from getting damaged. It also makes it clear when DIY ends and professional kitchen cleaning begins, especially for ducting and exhaust fans, which are hard to get to, more risky, and where grease builds up the most dangerously.
What Parts Are Actually Cleaned While Cleaning Your Kitchen Hood?
Cleaning a kitchen hood involves more than just washing the filters. A kitchen exhaust system is a series of pipes that carry grease away from the kitchen. Grease can build up at any point along the process. A normal system has:
Filters
The first barrier that captures oil droplets, however grease can also settle in other places.
Area for capturing the canopy
Grease film forms and drip points start on the bottom of the hood, the rails, the seams, the corners, and the light covers.
Throat and plenum
The area inside the hood where air flows turns and grease can build up past the filter line.
Duct entrance and ductwork
The path that grease takes from the hood to the discharge point, which is often where hidden buildup creates a long-term problem.
Fan for the exhaust Often on the roof and a high point of buildup, which can make extraction harder and raise the risk of fire if not taken care of.
Air that comes in (if there is any)
The supply air system changes the equilibrium of airflow. The hood might not be able to catch smoke well if it is unclean or not balanced.
Think of it as a whole system. According to Richmond Valley Council’s ventilation regulations for food establishments, cleaning one area helps, but it won’t address smoke, odors, or ventilation issues if grease is still lodged further in the channel.
Different kinds of Kitchen hood filters and how to clean them the right way
Hood filters aren’t all the same, and utilizing the improper approach can break the filter or leave grease behind. Here are the most common sorts and what to do with them.
Baffle filters are the most popular type.
Baffle filters employ metal channels to modify the direction of the air flow. This helps grease droplets fall out before the air flows deeper into the system. They last a long time and are usually safe to clean with regular degreasing procedures. Most of them are made of aluminum or stainless steel, and they can all handle a wash cycle like a dishwasher if your location has one.
Check for dents, broken welds, or warped edges to make sure the filter still fits snugly in the rack.
Filters with mesh
Mesh filters capture oil with thin metal layers, but they get clogged up faster and are tougher to thoroughly degrease because grease gets stuck in the mesh. If you don’t handle them carefully, they can also change shape. Some kitchens choose to have new ones when they continue sticky or obstructed even after cleaning.
Best practice: Don’t bend or twist them, and rinse them well so that the degreaser doesn’t get stuck inside the mesh.
Filters that look like cartridges
These are less prevalent and are usually only found on certain types of hoods. There are additional ways to clean, and some cartridges can’t handle strong chemicals or a lot of soaking.
Best practice: Follow the manufacturer’s instructions, especially when it comes to the strength of the chemicals and the temperature of the water.
If you’re not sure what kind of filter you have, search for a label on the filter frame or seek up the hood manual. Be extra careful with aluminum filters since powerful caustic chemicals might make the metal darker or create pitting.
When You Should Clean Your Kitchen Hood?
The kitchen will let you know right away if your hood isn’t pulling air well. Look out for these signs:
1. The hood sounds louder than usual.
The system might have to work harder because grease is blocking the flow of air.
2. During service, smoke stays in the air longer.
When the capture is bad, it usually signifies that the grease channel is partly obstructed or that the airflow is not balanced.
3. The stench of grease stays after service.
Old stuff inside the hood and duct keeps giving off smells even when you stop cooking.
4. A film that sticks or drops under the canopy
Grease on the bottom of the hood means it’s time for a more thorough cleaning.
5. Filters may look glossy, sticky, or full of dirt.
If the filters feel sticky or look glazed, that means that grease isn’t being removed effectively and can be going deeper into the system.
6. The walls, tiles, or ceiling around feel oily.
When the hood doesn’t catch the grease, it accumulates on nearby surfaces and creates a health risk.
7. Staff complain about the heat and smoke, or the fan doesn’t work well.
Less extraction makes the kitchen hotter, hazier, and less comfortable, especially during busy periods.
Safety First: Don’t Skip This During Kitchen Hood Cleaning
You can get hurt quickly when you clean a kitchen hood if you don’t follow the rules. This is because it involves electricity, hot metal, strong degreasers, damp floors, and working on a ladder. The things that hurt the most and do the most harm are:
- Electric shock or an unintentional start-up if the hood is not adequately disconnected before cleaning.
- When you use degreasers without following the safety instructions on the label and SDS, you could get chemical burns, hurt your eyes, or have trouble breathing.
- People slip and tumble on greasy or damp floors during wash-down, especially in confined kitchen passageways.
- When the ladder is unsteady, on a slippery surface, or you reach too far to strike corners and light covers, you can fall off.
- If chemical overspray gets on food, benches, utensils, or prep equipment, there is a risk of contamination.
If grease is visible in the ducting or around the fan housing, it is a sign of a higher risk, and you should not “reach in” with tools to fix it.
Minimum safety steps:
- Turn off cooking appliances and allow surfaces to cool.
- Switch off the hood and isolate power where safe to do so.
- Put up “wet floor” signs and keep the area clear.
- Wear PPE: gloves, eye protection, non-slip footwear, and apron.
- Never mix chemicals (especially bleach with acids or ammonia).
- Protect food, prep surfaces, and equipment from splash and overspray.
Avoid attempting to “reach in” with tools if you notice a lot of grease in the ducting or around the fan housing. According to NSW Health’s cleaning work procedures, it is a specialized task.
Tools and supplies you will need for Kitchen Hood Cleaning
Basic kit
- Heavy-duty degreaser suitable for kitchen exhaust work
- Spray bottles or pump sprayer (low pressure)
- Non-scratch pads and brushes (including a small detail brush)
- Plastic scraper (for thick build-up, avoid metal blades on soft surfaces)
- Microfibre cloths and disposable wipes
- Bucket, hot water supply, and rinse cloths(essential for proper rinsing; see our guide on how to clean a kitchen sink drain for related tips on handling greasy runoff)
- Drip trays or a liner to catch runoff
- Step ladder (stable, commercial grade)
Optional, but helpful
- Filter soak tank (or a large tub)
- Foaming degreaser for vertical surfaces
- Replacement filters or spare set (keeps the kitchen running)
Steps for a kitchen hood Cleaning
Step 1: Get the Area Ready (10 Minutes)
Plan to clean the hood when the restaurant is closed so you don’t have to deal with heat, food, or personnel moving around. To begin, move or cover up any food, utensils, and small appliances that are under the hood. Put down absorbent mats or a liner to catch drips, and then put a container nearby for filthy cloths and greasy runoff. Make sure the ventilation is off and the hood surfaces are completely cool before you touch anything. Hot metal and degreaser don’t mix well.
Step 2: Take out the filters and clean them ahead of time (5 minutes)
Take the filters out carefully and keep them upright while you do so, because they can spill a lot. If the grease is thick, scrape it into a bin first so you don’t have to soak a whole layer of sludge. Look at the filters for bent frames, warped metal, or broken welds. Damaged filters don’t sit right and can let grease get into deeper parts of the system. This step is important because if the filters are really clogged, the airflow may still feel weak even after you clean the hood underneath.
Step 3: Soak the filters and wash them for 20 to 60 minutes.
A hot soak is the safest and most reliable way. Fill a tub with hot water and add the degreaser exactly as the package says. Then, put the filters in the water and let them soak for a while to break down the buildup. After soaking, brush them to get rid of any dirt, rinse them well, and then stand them up to dry so that the water can drain out and they dry evenly. You should only use a dishwasher when your setup and site rules say it’s okay. Also, always rinse off any extra grease beforehand so you don’t coat the inside of the dishwasher. Be careful with aluminum filters since harsh chemicals can make the metal darker or pit it unless the substance is designated as safe for aluminum.
Step 4: Clean the Outside of the Canopy (10 to 20 Minutes)
Cleaning the outside is important for health, looks, and to keep grease from getting on hands and other surfaces. Before spraying the hood, put degreaser on a towel or pad first. This will help keep the spray from getting on walls, benches, or food-contact surfaces. Wipe down the outside of the canopy, the borders, and any signs, paying special attention to fingerprints and other places that get a lot of touch. Wipe the surface with a clean, moist cloth to get rid of any chemical residue, and then dry it to keep it from staining.
Step 5: Clean the Bottom of the Capture Area (15 to 30 Minutes)
The underside of the hood is where grease builds up the fastest, so take your time and clean in small sections. If it’s safe and authorized, take off the light covers and clean them separately. They typically hold oily haze. Put degreaser on the underside, seams, corners, and rails, then let it sit for the amount of time advised. Don’t let it dry on the surface. Use a non-scratch pad and a detail brush to scrub the corners, and then use clean cloths to wipe away any grease that has come loose. Rinse and wipe the area with clean water until all the residue is gone, and then dry it. This is because the remaining chemical film can attract more dirt later.
Step 6: Clean the Plenum Entry (Only If You Can Get to It Safely)
Some hoods only let you get to the plenum or throat area, which is where the air enters the duct. Use a long-handled brush or pad and a small amount of degreaser to get rid of buildup if you can safely reach it without taking anything apart. Be careful when you wipe and rinse so you don’t push any liquid deeper into the ductwork. If you see a lot of grease here, it’s a good clue that grease has probably gotten into the ducts and fan. This is normally when it’s best to call in a professional to clean them.
Step 7: Put the filters back in and check the airflow (5 to 10 minutes).
Make sure the filters are totally dry before putting them back in. If they are still wet, they might trap dirt and form fresh streaks. Put them back together so that there are no gaps, then turn on the hood and listen for any strange noises that could mean a loose fit or a blockage. Make sure the lights operate and that any covers are tight. To quickly check the airflow, hold a tissue close to the filter face while the system is running. You should observe a continuous pull toward the filter, which usually signifies the hood is working properly again.
How often should you clean the hood in your kitchen?
It depends on how you cook and how many people you serve. There isn’t one routine that works for every kitchen. For example, a bustling takeaway and a quiet café make significantly different amounts of grease. The more you cook and the more you use chargrills, woks, and deep fryers, the faster oil builds up on the filters, canopy, and concealed grease route.
Every day, wipe down touchpoints and look for grease on them.
Every day, quickly wipe off the outside of the hood and the places where personnel contact it the most, like the edges, handles, and adjoining surfaces. Spot-clean any grease you can see and check the filters quickly. This daily check helps you find problems with drips, smells, and smoke capture before they get worse.
Weekly: Clean the filters well and wipe the hood’s bottom.
Once a week, clean the filters and wipe off the whole bottom of the hood. This is the routine that usually makes the largest difference in controlling airflow and smells. This is because grease builds up fastest and earliest in the filters and the capture area.
Every month: a thorough cleaning of the seams, corners, and light covers on the bottom.
Once a month, do more than just a general wipe. Pay attention to the seams, corners, rails, and light covers where grease film hides and keeps spreading. A lot of kitchens find that the hood looks clean at first sight, but still feels sticky in the details at this time, therefore the monthly detail is important.
Every three to six months: A professional check-up and a review of the schedule
It’s a good idea to have a professional check the whole system every few months to make sure the cleaning schedule still fits how the kitchen is being used. This evaluation and any deeper cleaning normally need to happen more often at sites with a lot of traffic or grease, because grease can get past filters and into places you can’t safely get to.
Cooking with a lot of grease needs a faster beat.
If you use your kitchen’s chargrills, woks, or deep fryers a lot, you should clean the filters and the canopy more often than usual. These ways of cooking put more fat into the air, which makes things pile up faster and problems show up sooner.
Things you shouldn’t do when cleaning your kitchen hood
- Do not use metal scourers that are rough on stainless steel.
- Don’t let the degreaser dry on surfaces.
- Don’t spray water on electrical parts or light fixtures.
- Don’t force liquid grease into ducting.
- “Filters clean” does not indicate “system clean.”
When to Get a Professional to Clean Your Hood and Duct?
When grease seeps from seams or fan housing, or when smoke, heat, and burnt grease odors continue even after clean filters have been installed, professional like westlink commercial cleaners for kitchen hood and duct cleaning is required. These indicate a hazardous interior accumulation that increases the risk of a fire and necessitates expert access, meticulous cleaning, secure disposal, and compliance records.1.3s Fast. below explain it in detail
You can see grease near the duct entry or around access panels.
If you can see grease within the duct entry or around access panels, it usually signifies that grease has already migrated past the filters and into the duct system. At that point, cleaning the surface won’t cure the fundamental problem. It’s safer to call a professional because they can go to and clean the interior duct path correctly.
There is grease pouring from the seams or the fan housing.
If grease is dripping from the seams, joints, or fan housing, it’s a clear sign that the load is too heavy and expanding beyond the regular capture zones. This is a hygiene issue, and it’s also a bigger fire risk because grease is building up in locations that should be clean and dry.
Even once the filters are clean, smoke and heat keep piling up.
If the filters are clean but the kitchen still smells like smoke or is too hot, it’s possible that ventilation is blocked deeper in the system. That can happen when the ductwork, plenum, or fan blades are covered. A professional cleaning can get to places where DIY solutions can’t.
The stench of burning grease is really strong.
If you smell burnt grease all the time, it could be because old residue is sitting in the system and heating up during service. The scent can mean that there is a buildup in the plenum, ductwork, or fan region that has to be cleaned by a professional, even if the hood seems OK from the outside.
For auditors, landlords, or insurance, you require compliance documents.
Many places, especially leased kitchens or managed venues, need documentation that the exhaust cleaning system is being taken care of. A professional cleaner can give you the paperwork you need for insurance checks, landlord regulations, or hygiene and safety audits.
The roof fan is hard for workers to get to or not safe for them to reach.
Fans that are mounted on roofs are a typical place where a lot of things can build up, but they are also one of the most dangerous places for workers to go without the necessary tools and controls. Don’t take the chance if your squad can’t get to it securely. A professional can handle access, confinement, and cleaning the right way.
Why it’s important to hire a professional to clean your ducts and fans
When professionals clean ducts and fans, they utilize the right way to contain the dirt, get to it, and throw away the oil. It also lowers the risk of pushing grease deeper into the ductwork, which can happen if you try to clean it without the correct tools.
Quick checklist you can print
Before you start
- Cooking equipment off and cool
- Hood power isolated where safe
- PPE on
- Floor protected and signs up
- Degreaser and tools ready
During cleaning
- Filters removed, scraped, soaked, rinsed
- Exterior wiped, rinsed, dried
- Underside scrubbed (seams, corners, rails, lights)
- Residue fully rinsed off
After
- Filters dry and reinstalled correctly
- Hood tested for airflow
- Area sanitised and floors dry
- Cleaning logged (date, staff, notes, issues found)
Conclusion
It’s not simply the filters that need to be cleaned in a kitchen hood. To get genuine results, you need to clean the filters, the underside of the canopy, and the regions where film builds up first. At the same time, you need to maintain power, chemicals, and food-contact surfaces under control. If you can see oil near the duct entry, access panels, or fan housing, or if smoke and smells don’t go away after cleaning, it’s time to call a professional. In those situations, the safest method to get airflow back, lower the risk of fire, and keep your kitchen up to code is to hire a and book a professional services like Westlink Commercial Cleaning Company to clean the ducts and fans.
Frequently Asked Questions
What mistakes cause grease to come back fast after cleaning?
Common causes are:
- Only cleaning filters and skipping the underside/capture area
- Letting degreaser dry on surfaces
- Not rinsing residue fully (it attracts dirt)
- Reinstalling filters while still wet
- Pushing liquid grease toward the duct entry
Can I clean a kitchen hood with vinegar or dish soap?
For light wipe-downs, mild products can help, but kitchen hood grease often needs a proper degreaser designed for heavy kitchen fats. Vinegar also introduces an acid that can react poorly with some surfaces and should not be mixed with other chemicals.
Can I spray water directly into the hood or onto light fixtures?
No. Avoid spraying water onto electrical parts, wiring, and light fixtures. Use controlled wiping and rinsing with cloths. If you need to remove light covers, isolate power where safe and let everything cool first.
Why is my kitchen still smoky after I clean the filters?
Because grease may have built up beyond the filters, commonly in the plenum, duct entry, ductwork, or the exhaust fan. The system works as one airflow pathway.
Is steam cleaning safe for hood cleaning?
Steam can help on some surfaces, but it can also spread liquefied grease, affect seals, and introduce moisture near electrics. If you use steam, keep it controlled and avoid electrical areas.
Do I need to clean the exhaust fan too?
Yes, but fan cleaning is often a specialist task due to roof access, electrical safety, and containment requirements.
When does DIY end and professional hood cleaning begin?
Call a professional when:
- You can see grease near the duct entry, access panels, or fan housing
- Grease is dripping from seams or joints
- Smoke, heat, or smells persist even after cleaning filters
- Roof fan access is unsafe for your team
That usually means grease has moved deeper into the system where DIY cleaning is risky and incomplete.
