How To Clean Your Commercial Hood System: And How an Automated Hood and Flue Cleaning System Can Help

News & Blog

Restaurants and grease go hand in hand, but while that often means headaches in the form of cleaning the hood and flue system, it doesn’t have to. Cutting-edge technology removes the need for the dreaded third-party hood cleaning while keeping your restaurant up and running, safely, and to code. 

Top 3 reasons why commercial hoods need cleaning

There is no doubt regular hood and flue cleanings are essential, not only to keep your restaurant functioning at peak efficiency but for safety and liability reasons as well. 

Did you know in the most recent National Fire Protection Association (NFPA) report on “Structure Fires in Eating and Drinking Establishments,” 22 percent of the restaurant fires reported were attributed to a “failure to clean?” 

  1. Fire prevention: Kitchen exhaust systems that aren’t cleaned regularly are a fire hazard because they accumulate thick layers of grease and grime, which are flammable, and can act as fuel when a fire breaks out - a worst-case scenario for restaurants.
  2. Insurance liability: If a restaurant is operating beyond the due date of their required kitchen exhaust inspection, the restaurant takes full liability for any sort of loss due to a fire. 
  3. Productivity and efficiency: A clean kitchen hood and vent system reduces maintenance and increases efficiency. This results in increased airflow above the cooking appliances and allows the airborne grease, smoke and odors to properly exit the kitchen through an exhaust hood instead of lingering in the kitchen air and covering kitchen surfaces. In addition, a constantly clean kitchen exhaust system means there is less of a chance for unexpected breakdowns or interruptions that can impact your operations.


How often should commercial kitchen exhaust systems be cleaned? 

The NFPA sets the national guidelines for kitchen exhaust inspections and cleaning. All restaurants fall into one of four inspection categories according to the NFPA 96 Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations: 

  • Monthly: Restaurants using solid fuel such as charcoal or firewood need to be inspected each month. 
  • Quarterly: High-volume cooking operations, including 24-hour cooking, charbroiling, or wok cooking, need to be inspected quarterly. 
  • Semiannually: Restaurants with moderate-volume cooking operations are inspected twice a year. 
  • Annually: Establishments with low-volume cooking operations such as churches, day camps, seasonal businesses, senior centers, ski resorts, etc., are inspected once a year. 

While the states have to meet minimum guidelines, local jurisdictions can be more strict than their state or federal minimums mandate.

Routine kitchen exhaust system inspections are handled by a third-party vendor who also cleans the grease accumulation from the entire kitchen exhaust system if needed. If the restaurant passes inspection, or the system has been cleaned by the vendor, they will put the updated inspection sticker on the side of the clean exhaust hood canopy showing when it was inspected or cleaned, and when it is due for its next vendor visit. Typically, local fire marshals are also conducting a separate unannounced inspection once a year to ensure that the restaurateur is operating within the two dates on the inspection sticker.

If a fire marshal arrives and an inspection is past-due, several things could happen. They could shut the site down immediately for not adhering to NFPA standards. Or, the fire marshal may provide a time frame to address the vent cleaning, perhaps 48 or 72 hours, and then come back and make sure the vent and hood were cleaned and passed inspection. If the issues haven’t been addressed, the fire marshall could then shut the restaurant down. Sometimes, a fine may also result.   


How does third-party hood cleaning work? 

Hood and vent cleaning is a messy job. To get started, the areas around the kitchen hood need to be cleared out, which means appliances get unplugged and moved, pilot lights go out, gas lines are disconnected, etc. Once the area is emptied, Visqueen plastic is hung from the vent hoods and funneled down into a trashcan to catch all of the grease, water and detergent from the cleaning process. Then, power washers are used to clean everything from the hood canopy through the ductwork and up to the rooftop where the exhaust fan sits. 

Once the system has been power washed, the trashcan collecting all of the debris is emptied into a mop sink. This can sometimes lead to clogged pipes and sewer contamination with fats, oils, and grease.

During the hours-long cleaning process, restaurants that are open 24 hours a day have to shut down, and those who are closed in the evenings often have to hire someone to stay through the night and supervise. Once the cleaning service is finished, the exhaust system may be clean, but the rest of the kitchen is often in disarray. Splashing from the power washers can leave water and residue all over the kitchen. Rooftop breaker switches are sometimes not turned back on, which means nothing works in the kitchen until it’s resolved. Everything that had to be moved for the cleaning must be put back, reconnected, and cleaned. 

As if all these issues weren’t frustrating enough, one of the most common complaints from restaurant operators regarding kitchen exhaust cleaning is how much inconsistency there is in the cleaning process. While it is easy to see the hood canopy from the cookline, the ductwork and exhaust fan are difficult to see and, therefore, it is challenging to ensure that these areas have been cleaned properly, if at all. 


What makes for a good exhaust system?

There are four primary parts in a typical kitchen exhaust system

  • Exhaust Hood - This large stainless steel canopy is mounted above the cooking appliances. It is designed to hold the baffles, while funneling the airflow into the ductwork. 
  • Baffles - Also known as hood filters and often made of metal, their primary role is to prevent any flare ups from the cooking appliances from reaching further than 18 inches into the hood and flue. Some baffles are also designed to have a secondary purpose to filter grease and solid fuel embers. If they aren’t routinely cleaned, the grease laden hood filters can be as much of a fire risk as a grease filled kitchen exhaust system.
  • Ductwork - Made up of large pipes that connect the exhaust hood canopy to the exhaust fan, ductwork moves the cooking exhaust outside. 
  • Exhaust Fans - Typically found on the rooftop, exhaust fans suck the smoke and grease laden kitchen air up through the hood and ductwork.

In order to maximize your exhaust system productivity, there are several things you can do:

  • Use the correct baffles. This isn’t a place to cut corners. Not only would it create a fire hazard, but it will also make your equipment less efficient. Be sure to use the recommended filters for your system and ensure your hood filters cover the entire hood canopy opening. 
  • Install duct access doors. As mentioned above, it is nearly impossible to determine the condition of your ductwork since it is so challenging to see. Remedy this by adding duct access doors along the ductwork. This allows visibility to the ducts’ condition and allows easier access to clean them. 
  • Install an exhaust fan access port. When cleaning the exhaust fan, it is difficult to access the fan blades to wash them. An easy solution and an NFPA 96 fire code requirement is an exhaust fan access port that allows access to the fan blades to wash them. Not only does this help with the cleanliness of the system, but it also lengthens the life of the fan by preventing unbalanced fan blades and excessive fan belt wear and tear, which can result from the fan being covered in grime. 
  • Install an exhaust fan hinge kit. Instead of having third-party cleaners remove your exhaust fan several times a year, a hinge kit allows them to tip the fan back to gain access to the ductwork. This prevents damage to the fan base, fan components, and damage to your roof that can happen during cleaning.  
  • Clean hood filters regularly. While the entire system is being inspected and cleaned up to four times a year, your hood filters should be cleaned on a much more frequent basis. A QSR will probably be cleaning their hood filters daily, while other restaurants may only need to clean theirs once or twice a week. Refer to your hood filter manufacturer for more precise details.     


The Restaurant Technologies way 

Thankfully, the days of dealing with messy hood, flue, and fan cleaning can be left behind. Restaurant Technologies offers two solutions that can either completely eliminate the need for future third party kitchen exhaust cleanings or simply reduce the need for hood cleanings by up to 75%. Additionally, in today’s reality of labor shortages, these automated solutions can achieve labor savings. 


Grease Lock: Exceptional grease filtration

Grease Lock is a patented disposable fiber-based hood filter that captures up to 98% of airborne grease before it enters the exhaust system. Made of two components, the metal frame acts as a fire barrier and is required by the national fire code, while the biodegradable filter pad absorbs the grease and is noncombustible.

Restaurateurs using Grease Lock are able to show some significant savings immediately. 

“Most standard operating procedures require staff to clean metal hood filters every day which is also recommended by hood filter manufactures,” shared Jordan Salpietra, Grease Lock Product Manager. “With Grease Lock, this daily deep cleaning may now be reduced to once a month or less. That deep cleaning typically takes an hour to do, so that’s 365 hours of labor without Grease Lock versus 12 hours with Grease Lock.”

Vent Hood Air Flow Image with No Text Overlay

AutoMist: Cleaning while you’re cooking

AutoMist is an automated system that cleans the kitchen exhaust system daily without having to shut down operations.

“AutoMist runs while the restaurant is operating,” said Katie Dye, AutoMist Product Manager. “That is one of the reasons why AutoMist is a great fit for stores that are open 24 hours a day. They never have to shut down to clean their kitchen exhaust system.”

The automated cleaning takes place behind the baffle filters. Grease is washed out and collected in a container that is easy to empty daily, or directed to a floor drain with a grease trap. The detergent used in the system is easy to replace, food safe in its diluted form, safe to dispose of down the drain and has a triple zero hazmat rating, making it safe for employees to handle.  

Restaurant Technologies can eliminate or reduce the need for third-party hood cleaning while reducing risk from prolonged grease build-up and freeing up labor. Contact Restaurant Technologies’ Customer Care Team today to set up a free consultation at 888-796-4997.