How to clean a kitchen exhaust fan
If the exhaust fan includes mesh filters, remove them and pour boiling water through them.
If the exhaust fan includes mesh filters, remove them and pour boiling water through them.

1 For the mesh:
If the exhaust fan includes mesh filters, remove them and pour boiling water through them. Soak them in a mixture of hot water and ammonia (1/2 cup ammonia to 1 gallon of water) for an hour. Remove the mesh from the soaking solution and scrub the solution around the mesh. It’s not just the filter that accumulates fat, the fan blades do as well. Use sodium phosphate cleaner for cleaning blades! (wear a mask when you use this)
2 For fan blades:
Prepare a mix of water and soap or you can also add a mixture of 1/4 ammonia, 2 tbsp baking soda and 1 cup full of warm water. Put on the rubber gloves and, using the above mixture and cotton cloth, scrub the exhaust fan blades and then the rest of the body.
3 To break down the grease:
Caustic chemicals can be applied to break down the grease. After that, hot water can be used to rinse away the residue. Chemicals are generally applied with either a garden type sprayer, downstream injection through a pressure washer or with
a chemical foamer.
4 Scrape it up:
Use scrapers where grease buildup is too heavy before applying chemicals. Remove the dirt and grease by using the small steam cleaner. Take a mild wet cloth or towel and wipe the equipment inside out to make sure that each part is dirt free.
5 Cut through the dirt:
Working from the back, scrub the fan housing and the fan blades. You’ll need to keep drying the areas you’ve completed with paper towels. You can also clean it using vinegar or window cleaner or any dish washing liquid with a toothbrush. It will cut through the dirt and greases that build up in the fan.