Aerotech Fans
Loading industrial-grade components...
Technical answers to common questions about kitchen exhaust.
Boiling water in pasta cookers or steam kettles dumps massive amounts of latent heat (moisture) into the kitchen. If the Exhaust Air Unit does not fully capture this steam, the latent load overwhelms the dining room's AC unit, causing condensation on windows and creating an uncomfortably clammy environment.
Commercial kitchen balancing requires the Make-Up Air (FAU) to supply roughly 80% to 90% of the air volume extracted by the exhaust fan. The remaining 10% to 20% deficit creates a slight negative pressure, ensuring food odors are kept inside the kitchen rather than drifting into the dining room.
For standard commercial cooking equipment, the exhaust hood must maintain a capture face velocity of 50 to 75 Feet Per Minute (FPM). For heavy-duty solid fuel or charbroiling, the velocity must be engineered closer to 100 FPM to ensure the thermal plume is completely captured.
In a fire emergency, preserving human life by maintaining a smoke-free escape route supersedes protecting the equipment. Smoke spill motors are hardwired to bypass all VFDs and thermal overload relays, intentionally running the motor to destruction rather than tripping and allowing the building to fill with toxic smoke.
To retrofit Demand Control Ventilation (DCV), you must install optic smoke sensors and temperature probes inside the existing canopy, and connect them to a new VFD wired to the Exhaust Air Unit (EAU). The system will automatically modulate the fan speed based on real-time cooking loads.
According to IMC (International Mechanical Code), the fresh air intake for a Make-Up Air unit must be located a minimum of 10 feet horizontally from the kitchen exhaust fan discharge to prevent short-circuiting and drawing toxic grease and smoke back into the building.
Grease leakage on the roof indicates a failure of the fan's integrated grease trap, or the use of a standard ventilator instead of a UL-762 rated upblast exhaust fan. Upblast fans feature a fully welded, leak-proof base and a discharge spout designed to safely route grease into a collection box.
DCV systems utilize optic smoke sensors and temperature probes inside the exhaust hood. Instead of running the exhaust fan at 100% all day, a Variable Frequency Drive (VFD) automatically scales the fan RPM in real-time to match the exact cooking load, saving massive amounts of electrical and Make-Up Air heating costs.
A dry scrubber uses an Electrostatic Precipitator (ESP) and activated carbon to magnetically capture smoke and absorb odors. A wet scrubber (Ecology Unit) uses a continuous high-pressure water and surfactant spray to physically wash the grease from the airstream and extinguish live embers.
Adding a wet scrubber (Ecology Unit) requires evaluating the existing ductwork and fan static pressure. Wet scrubbers induce a significantly higher pressure drop than dry ESPs, typically requiring the exhaust fan to be upsized or the motor replaced to handle the new aerodynamic resistance.
Commercial mechanical codes require the exhaust fan and the Make-Up Air (FAU) unit to be electrically interlocked. If the exhaust fan turns on, the MUA must automatically engage to prevent severe building depressurization. If the MUA fails, the exhaust must shut down.
Certified commercial smoke spill fans are engineered with Class H motor insulation to operate continuously for either 2 hours at 250°C, or 2 hours at 400°C, depending on the specific local fire-code compliance and building life-safety requirements.
