As Operations Manager and a Certified Exhaust System Inspector (CESI) for Hood Boss of Austin, I visit many types of facilities and inspect numerous types of kitchen exhaust systems. Besides following up on the quality of work of our technicians, most of my visits are to inspect the work of other vent hood cleaning companies. I have a trained eye to look for the areas that many vent hood cleaning companies have a habit of overlooking or do not consistently give attention. I do not consider these visits as a sales call and I never use it as an opportunity to “bash” a competitor. I consider it as an opportunity to educate someone on the importance of our service and what should be considered quality workmanship.

Let’s start with the codes that my industry follows, NFPA 96 Standard, Sec. 11.6.1 “If upon inspection, the grease exhaust system is found to be contaminated with deposits from grease-laden vapors, the contaminated portion of the exhaust system shall be cleaned…”. Basically, it states that any area of the system that has over a 1/8th of an inch of grease should be cleaned. Keeping in mind that grease accumulation is fuel for a fire, even without knowing codes, common sense tells me that fuel closest to the fire source will help a fire to grow.

I will focus in on a few areas of the exhaust hood closest to the fire source that I tend to look for when following up on a vent hood cleaning service. This information will be useful when following up on your current services with the intention of upholding an industry wide standard of cleanliness and safety.
Filter Tracks – the upper and lower filter tracks are the key component to keeping your baffle filters securely in place.
The lower track is a high accumulation area of stored grease/fuel. The lower track is designed to capture the grease dripping out of small holes in the bottom of the baffle filters.

Lower Track (Before)

Lower Track (After)

The track has a slight grade that allows the grease to run to either side of the hood to grease cups in the corners. This area should not only be grease free after a cleaning but should also be cleaned by kitchen staff between full vent hood cleanings.

The upper track creates an angled area inside the hood that allows for grease to accumulate behind the track. It is typically not the liquified grease you will find in the lower track; it is more of a thick black grease that sticks to the inside of the hood and is just as flammable.

Upper Track (Before)

Upper Track (After)

This area is commonly neglected because it is a difficult area to reach with a pressure washer wand and typically will need to be cleaned by hand. You will find the accumulation heaviest as it gets closer to the duct opening or duct collar.
Duct Collar – the duct collar connects the hood to the duct work leading to the exhaust fan. the important thing to remember is that there are four sides to the duct collar, 3 that are easily visible when standing at ground level with the filters out and 1 that is only visible by actually getting at eye level with the back side of the collar. Backside meaning the side that is facing the wall side of the hood. This area is also neglected because of its difficulty to clean and the “who is going to check there?” mentality.

Barney Basel (founding member of the International Kitchen Exhaust Cleaning Association) once stated, “There are two kinds of restaurants – ones that have had a fire and the ones who will be having their fire.” There is great danger leaving this fuel stored so close to ignition point and yet, I find it in many places. Stored fuel feeds the start of a fire and helps it grow. After every service, an exhaust company is required to place a certificate of performance sticker on the hood that states that the system is “Cleaned in accordance to NFPA 96…”. Do not let this sticker be a false sense of security. A reputable company should follow up with photo documentation of these areas and all other areas of the system. As professionals involved directly or indirectly with public safety it is important to be educated about the dangers that potentially exist in the kitchen exhaust system.