Kitchen ventilation rarely gets attention until something goes wrong: smoke drifting into the dining room, a burnt-oil smell on a busy evening, or a fire inspector asking for the last cleaning record. Grease leaves the hood as vapor, cools as it travels through the ductwork, and settles as a sticky film that hardens over time. Once that film builds up, ordinary wiping no longer removes it. Before arranging a cleaning, whether your own staff will do the work or you hire a contractor, the questions below help you understand what is actually being cleaned, how it will be done, and what you should expect in writing.
Start with the list of components
A commercial kitchen ventilation system has more parts than the hood you can see. A complete cleaning job normally covers:
- the interior and exterior surfaces of the exhaust hood and its grease catch trough
- grease filters and baffles, the first place grease collects
- the ductwork between the hood and the fan, where hardened deposits build up on the inner walls
- the exhaust fan, its blades and housing, which lose airflow and run noisily once coated in grease
- the make-up air unit that draws fresh air into the kitchen
- the exterior discharge point, often skipped because it sits on the roof
Ask any provider to state in writing which of these are included in the quoted price. Quotes that cover only the hood interior and the first stretch of accessible ductwork are common, and the fan is the component most often left out. For kitchen exhaust duct grease cleaning, ask specifically how the crew will reach horizontal duct runs, whether access panels will be cut and resealed, and how the duct interior is inspected before and after the work.
Ask how often each part needs cleaning
There is no single interval that fits every kitchen. A wok range or a deep fryer sends far more grease into the air than a sandwich counter or a baking station, so your menu and daily cooking volume set the schedule. Fire codes such as NFPA 96 in the United States tie required cleaning frequency to cooking volume, and your local fire authority sets the rules that apply to you. Ask your provider what interval they recommend for your operation, get that recommendation in writing, and keep dated records of every cleaning, because inspectors and insurers ask for them.
Ask what cleaning method will be used
The traditional method is manual: scrape what you can reach, spray a chemical degreaser, let it soak, then rinse with hot water. It works, but it means harsh chemicals near food surfaces, long soak times, a soaked floor, and often several hours with the kitchen closed.
An alternative worth asking about is restaurant exhaust hood steam cleaning. Dry or wet steam generated at high temperature and pressure softens polymerized grease that chemical sprayers struggle to dissolve, so the deposit lifts off with little or no detergent and far less rinse water. Ask whether the method leaves standing water on the floor, whether any chemicals will contact surfaces near food preparation, and how long the machine needs to heat up before work can start.
Ask whether the work can be done around your service
A closed kitchen earns nothing, so ask whether the job can be split into sections and done outside service hours. A crew that cleans the hood in the morning and the ductwork overnight, with the kitchen reopened between sessions, is very different from one that needs the whole room for a full day. Also ask how long surfaces stay wet after cleaning and when it is safe to resume cooking. Some methods leave the kitchen usable almost immediately, while others require a full dry-out.
Ask where the removed grease goes
Scraped and rinsed grease has to go somewhere. If it is washed straight into floor drains, it re-deposits further down the plumbing and turns into a blocked drain a few weeks later. Ask whether the crew collects and removes the waste grease, how the floor is protected during the work, and who is responsible for the final clean-up.
Ask what documentation you will receive
After the job you should receive a dated report listing the components cleaned, before-and-after photos of the duct interior and the fan, and notes on anything that needs attention, such as a damaged access panel or a fan that is difficult to start. This paperwork is what fire inspectors and insurance assessors ask for, and it is also how you judge whether the cleaning schedule is actually working.
Ask practical questions about the cleaning machine
If you plan to clean more often with your own staff, ask about the equipment itself: what power supply it needs, whether a standard single-phase outlet is enough or a three-phase connection is required, whether it connects to a water inlet or carries its own tank, whether it fits through the kitchen door and moves without trailing hoses across a hot, wet floor, and what safety protections it offers. Leakage, short-circuit, over-temperature and low-water protection all matter in a kitchen environment.
Before you make the call
A provider who answers these questions clearly is usually worth the phone call, and vague answers tell you a great deal. If you are evaluating steam-based options for your own kitchen, PowerDe's range of commercial steam cleaning equipment covers fixed, hand-pushed and mobile high-temperature, high-pressure machines with dry and wet steam modes. Describe your kitchen layout, cooking volume and available power supply to the PowerDe team before choosing a machine, so the recommendation matches how your kitchen actually runs.
