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Q: Why does my hood fan breaker keep tripping?

A: Often times it is the motor overheating and going bad. Sometimes the breaker itself is bad.

Q: Why is it hot even though the hood seems to be working fine?

A: It can be the swamp cooler/make-up air isn’t working.

Q: Why is the swamp cooler blowing warm air?

A: Usually this is because the water pump isn’t working.

Q: My hood works but doesn’t pull out the air as well as it used to. Why?

A: This is usually due to the belt being loose.

Q: Why does my hood fan screech, but only when I start it up?

A: Often it is because the belt is loose, so it takes a moment to catch up with the motor, kind of like a car burning rubber.

Q: Why is my fan making a metal-on-metal grinding sort of noise?

A: It’s often due to bad bearings.

Q: Why is my fan shaking?

A: This could be due to bad bearings and an out of balance fan wheel.

Q: Why did my exhaust fan just stop working?

A: There can be several reasons for this. Some are: the belt could have broken; the motor may have over-heated or died; there could be an issue with the electrical.

Q: Why is my kitchen smoky?

A: If the hood fan is still working, yet it is smoky, it is most commonly a new belt that’s needed.

Q: Why is it smoky in the kitchen even though the fan seems to be working fine?

A: Occasionally the hood filters may be clogged to a point where it is restricting the airflow.


Kitchen Exhaust System Terms

  1. Hood: A device containing mechanical fan that hangs above the stove or cooktop in the kitchen. It removes airborne grease, combustion products, fumes, smoke, heat, and steam from the air by evacuation of the air and filtration.
  2. Ducts: These are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air.
  3. Exhaust Fan: This is a fan designed to pull air out of a specific location and vent it outside to remove unwanted heat, smoke or other gasses.
  4. Grease Filters: Installed in the kitchen hood, these trap and remove grease particles present in the extracted air to prevent them from entering the ductwork and exhaust fan.
  5. Fire Suppression System: A system installed within the hood and ducts designed to extinguish fires by automatically dispensing a liquid chemical suppressant.
  6. Airflow: The volume of air moved by a fan in a specific amount of time, usually expressed in cubic feet per minute (CFM).

Make-Up Air System Terms

  1. Make-Up Air Unit (MUA): A device used for replacing air that has been exhausted out of a building. These units can be used to heat, cool, dehumidify, or simply replace the exhausted air.
  2. Supply Fan: This is the component in the MUA that forces fresh, replacement air into the building.
  3. Air Balance: A process for optimizing an HVAC system to ensure that the correct amount of air is being delivered in the right places. This is crucial in a kitchen environment to prevent issues like cross-contamination of food or uncomfortable drafts.
  4. Direct Fired Make-Up Air Unit: A type of MUA that heats incoming air using a gas burner directly in the air stream. These units are efficient but do not filter the incoming air.
  5. Indirect Fired Make-Up Air Unit: In these units, the heating element (gas, electric, hot water, etc.) is separate from the airflow, allowing the incoming air to be filtered.
  6. Dampers: These are adjustable plates located in ductwork that regulate airflow. They are typically used in zoning or balancing functions.

Contact Bryan Exhaust Service for all of your kitchen exhaust cleaning and hood cleaning services in Los Angeles.

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