Hood Cleaning & Grease Trap Questions, Answered Straight

NFPA 96 (2024) Table 12.4 sets inspection frequency by cooking volume: monthly for solid-fuel cooking, quarterly for high-volume operations (24-hour, charbroiling, wok), semiannually for moderate volume, annually for low-volume kitchens like churches and seasonal operations. Cleaning is triggered when the inspection finds grease at the trigger depth, though high-volume kitchens end up cleaned on roughly the inspection cadence in practice.

It's enforceable. Sioux Falls adopts the 2021 International Fire Code through Chapter 91 of its Code of Ordinances (effective January 1, 2022), and kitchen exhaust falls under IFC Section 606, with inspection frequency per Table 606.3.3.1 and cleaning to ANSI/IKECA C10. Sioux Falls Fire Rescue enforces it.

Measured grease depth. Under NFPA 96 §12.6.1, deposits are measured with a depth-gauge comb, and the system needs cleaning at 0.078 inches (2000 microns) on surfaces or 0.125 inches in fan housings. Inspect on the Table 12.4 schedule, measure, clean when the numbers say so.

Single-hood systems typically run $300–$700 per service (small hoods $200–$450, large or complex systems to $800+); multi-hood lines of 2–4 hoods run $800–$1,500. Hood count, duct run length, roof access, and grease load move the number — a free walkthrough gets you a firm quote. Full table on the pricing page.

It's the NFPA 96 endpoint: after cleaning, residual combustible contaminant can be no more than 0.002 inches (50 microns) anywhere in the system — hood, plenum, duct, and fan. Visibly shiny stainless over the cookline doesn't prove it; the duct interior is where the standard is actually met or missed.

The whole system — canopy, baffle filters, plenum, ductwork, and the rooftop fan. Grease that escapes the filters condenses in the duct, and that hidden accumulation is the fuel a fire rides from the cookline to the roof. A canopy-only wipe-down leaves the dangerous part untouched.

South Dakota imposes no state license for hood cleaners. NFPA 96 requires the work be done by properly trained, qualified, and certified persons acceptable to the authority having jurisdiction — in practice, crews carrying IKECA credentials (CECS, CECT, CESI). Sioux Falls Hood Cleaning connects kitchens with certified, insured local companies; ask any bidder to name their certifications.

Three things: before-and-after photos (including duct interior and fan), a written service report, and a dated certification sticker on the hood. That's what fire inspectors ask to see and what insurance carriers request after an incident. If a company doesn't provide photos, you can't verify the duct was touched.

Yes — the work is done overnight. Crews arrive after close, protect the cookline and equipment, clean the full system, and leave the kitchen dry and reset before morning prep. Filter swaps mid-rush are a no; that's the whole point of after-hours scheduling.

A single-hood system with a short duct run is typically a few hours overnight. Multi-hood lines, long duct runs in multi-story buildings, or systems overdue for service take longer — sometimes a full overnight window. The walkthrough sets the time estimate along with the price.

The city doesn't prescribe a calendar — your discharge limits do. Sioux Falls levies a sewer surcharge when discharge exceeds 100 mg/L of grease (§51.081(d)), and the industry best practice — EPA-recommended, not a city ordinance — is the 25% rule: pump when grease and solids reach a quarter of trap capacity. For most kitchens that works out to a regular route interval matched to how much you fry.

Indoor traps (20–100 gallons) typically run $150–$450 per visit, with recurring-route pricing flooring around $125. In-ground interceptors up to about 1,000 gallons run roughly $325–$950 per visit. Trap size and access set the price; you get a manifest documenting legitimate disposal.

Size and placement. Indoor traps are small vessels — under-sink or floor-mounted, 20 to 100 gallons — close to the fixtures. In-ground interceptors are large buried tanks, 500 to 3,000+ gallons, that serve the whole building. Same physics, different scale, different service visit.

Inside city limits, Sioux Falls runs South Dakota's only municipal health department, inspecting roughly 800 establishments under the state food code. In Brandon, Harrisburg, Tea, and Dell Rapids, kitchen licensing runs through the South Dakota Department of Health. Fire-code enforcement of your exhaust system is separate from either.

Yes — rush and pre-inspection service exists, at a 25–50% premium over standard pricing, because it means reshuffling an overnight route on short notice. It's the most expensive way to buy the same cleaning. A standing schedule matched to your cooking volume costs less and ends the scramble.

Yes — Brandon, Harrisburg, Tea, and Dell Rapids, at the same published pricing as Sioux Falls addresses. The fire-code requirements on your exhaust system are the same; what changes across the city line is which health authority licenses the kitchen.

No honest company guarantees an inspection outcome — the conclusion belongs to the inspector. What a proper service guarantees is a system cleaned to the bare-metal standard and documentation proving it: photos, report, dated sticker. That package is what inspections go smoothly on.

A hinge kit lets the rooftop fan tip open on a hinge instead of being lifted off its base, so the fan interior and the top of the duct get fully cleaned every visit without damage to the fan or the curb. Installs run $150–$300. If your fan has never been opened during a 'cleaning,' that's worth fixing.