Kitchen Exhaust Odour & Grease Control
Odour and grease control for restaurant and commercial kitchen exhaust systems.
Treating the Smell Inside the Ducting
Cooking smells do not stop being a problem once they leave the kitchen. Grease coats the inside of the ducting.
The smell carries into the car park, the lift lobby, the corridor upstairs, or the flat across the road.Â
ProMedUSA supplies ozone systems for commercial kitchen exhausts in Singapore, including hotel kitchens, restaurants and food courts. Each system is selected for the duct layout, airflow and cooking load.
What Ozone Does Inside the Duct
Ozone is a gas made of three oxygen atoms. It reacts with the compounds carried in the kitchen exhaust. In this application, it is introduced into the exhaust hood and the exhaust duct for treatment before the air is discharged outdoors.
Two things happen. Less grease builds up along the duct walls (and hood), so cleaning is needed less often and there is less grease sitting in there. And the exhaust odour is reduced or eliminated completely.
Ozone is injected inside the duct and exhaust hood, and is not released into the kitchen or dining room. The installation prevents leakage and backflow into occupied areas. Fan controls to switch the ozone on and off when the hood’s fan is turned off and commissioning checks are part of the design.
Ozone Equipment and Oxygen Supply
We select the ozone generator and oxygen supply as a system. The equipment must suit the exhaust airflow, cooking load, available space and service access.
Compare the rated ozone output, feed-gas requirements, maintenance instructions and warranty of the proposed model. These details are more useful than a general claim about one construction material.
All our kitchen exhaust systems run on oxygen, not ordinary air. Using Oxygen as the feed gas roughly doubles the ozone concentration produced. The ozone concentration is the most important element to ensure grease and odour removal.
Two Ways We Do It
Oxygen-Fed Ozone Systems
The generator makes ozone using oxygen supplied by an oxygen concentrator and feeds it into the exhaust duct. We select AZCO or Absolute Ozone equipment to suit the airflow and cooking load. The generator is interlocked with the exhaust fan so it stops when the fan stops.
Earlier UV Ozone Installations
Before high output oxygen-fed machines were available to us, we fed UV ozone straight into the ducting. It worked. It is still working – one installation from around 2019 has run for seven years eliminating serious food odours.
We would not fit it in a busy new kitchen today, because the oxygen-fed machines handle modern grease loads better. But it is still a sound approach for lighter jobs.
Where These Systems Are Running
The following ProMedUSA projects are described by type of business to protect customer confidentiality. All are in Singapore and all are still running.
- A five-star hotel — back-of-house kitchen exhaust.
- A Korean restaurant — tabletop grill exhaust. — a much heavier load than a normal kitchen.
- Another five-star international hotel – kitchen ducting.
- A chain of yakitori restaurants — charcoal grill ducting.
- A Singapore flavour and fragrance factory —five separate ozone systems on five separate installations at one site.
- A transport company’s food court — UV ozone fed into the ducting, six machines, running seven years with minimal maintenance
The oxygen-fed projects listed here use AZCO SGWV-DG3 generators at 23gm/hr ozone output, fed with oxygen concentrators. Equipment selection for a new project depends on its own exhaust conditions.
The flavour and fragrance manufacturer first bought one system and later bought four more for the same facility. A customer buying again four times is a harder test than anything we could write in a brochure.
Why Factory Exhaust Needs Its Own Assessment
Restaurant ducting is mostly grease and cooking smells.
Kitchen exhaust and factory exhaust can contain different compounds. A flavour and fragrance process may release strong-smelling substances. We need to understand the process, airflow and discharge location before recommending treatment. The complaint risk is completely different, and so is the sizing.
For a factory enquiry, send us the process details and describe when and where the odour occurs.
What We Do When You Call Us
1.. We assess the duct layout, airflow, cooking load, discharge point and nearby occupied areas.
2. We size the machine to your air flow and your cooking load or odour load. We do not pick one out of a catalogue.
3. We select the injection point and assess contact time before discharge.
4. We wire the machine to the exhaust fan so it only runs when the fan runs.
5. We commission the system, explain how to operate it and set out its servicing requirements.
Warranty
| Product | Ozone Generator Warranty | Ozone Generation Method |
|---|---|---|
| AZCO Ozone Generators | 3 years | Sealed rose quartz glass and stainless steel |
| Absolute Ozone | 5 Years | Sealed glass and stainless steel |
| ProMedUSA UV Ozone Generators | 6 years on the unit, 2 years on the UV Ozone Generating tubes | Proprietary UV Glass tubes |
Questions and Answers
Does any ozone get into the kitchen or the dining room?
No. The ozone goes into the duct and exhaust hood and travels out with the extracted air. The machine is wired to the exhaust fan, so it only makes ozone while the air is being pulled away.
Do I still need to clean the ducting?
Yes… BUT..Grease builds up more slowly, so you clean less often. But you still need to clean them, just much less frequently.
Is this the same as the plate machines I have been quoted?
No. Plate machines use ceramic or mica/steel mesh plates that corrode quickly in damp air and need regular scrubbing and replacing. Ours use sealed glass, which does neither. You will see the difference two years, not on the quotation. Our ozone generation methods require no servicing.
How long do these last?
Our oldest kitchen installations have been running about 8 years now. AZCO machines have a three-year warranty. Absolute Ozone has a 5 year warranty. Our own UV ozone machines have a six years warranty on the machine and two years on the tube with no conditions.
Can you handle a factory, not a kitchen?
Yes. We have five systems running at a Singapore flavour and fragrance factory, treating scent chemicals rather than cooking grease.
What size do I need?
It depends on air flow, how much you cook, or the type of odours present, and how long the ducting is. A Korean restaurant with table grills and a hotel kitchen need different systems than a fragrance factory, even if the exhaust fans are the same size. We size it on site.
Is it safe for my kitchen staff?
Yes, because nothing is released into the space where they work. The injection point is inside the ducting, downstream of the hood.
The fan interlock is the other half of the answer. The machine cannot run unless the fan is running, so there is no situation where ozone is being made into still air.
If your safety officer wants it measured, we will measure it. We own a calibrated ozone meter and we are happy to take readings in the kitchen at commissioning and give you every number.
Will ozone damage my ductwork?
No. Our oldest kitchen exhaust installations have been running for about seven years, and not one has shown corrosion, pitting or any other damage to the ducting.
Ozone is dosed at the level needed to treat the air passing through, not at a level that attacks the duct itself. And because far less grease builds up, the duct is in better condition than it would otherwise have been. The before and after photographs on this page show the same ducts months apart.
How long does installation take? Do we have to close the kitchen?
About an hour, sometimes less, for a single duct. And no, you do not have to close.
The work is running the tubing and drilling the injection point. None of it happens in the kitchen itself and none of it interrupts service. We have fitted these in working hotels and restaurants without the kitchen stopping.
How often does it need servicing?
Once or twice a year, depending on how hard the kitchen works.
The only part that needs servicing is the oxygen concentrator. Everything else is sealed glass, which does not corrode and never needs scrubbing. That is the whole maintenance schedule.
Take Control of Kitchen Exhaust Odours
Kitchen exhaust is not something you buy off a shelf. Send us your duct drawings and fan sizes, or let us come and look.