Excess oil in fan grease trap after stir frying in a wok I use a steel wok on induction. When I weekly check the fan grease trap, there's enough oil to run a 1957 DeSoto through the Nevada desert and still have plenty left over for John Travolta's hair.

When I travelled Asia, the chefs always seemed to douse the food in oil (and stock), and my own impression is that without sufficient oil, it feels as if "nothing's happening" in the pan.

In particular, vegetables like broccoli, seem to absorb oil like there's no tomorrow. I use rapeseed oil and run my wok on 85% of maximum heat, which seems to be the perfect temperature.

My question: How much oil is required for a standard one person wok meal, and how do I make sure the oil goes into the food, not into the fan?

(I'd also appreciate a physical/chemical explanation of why this happens. I assume it's because of the high temperature, that the oil is transported along with the "smoky" streaks from the cooking.)

Update: An important part of the problem is how the Swedish quality fan is constructed: The oil caught in the grease trap will slowly drip down outside the outer edges of the fan screen onto the induction top. Is this a problem with all kitchen fans, or could I solve the problem by replacing it?
Partial answer to the new formulation: 


  how do I make sure the oil goes into the food, not into the fan? 


You don't. The oil is not supposed to go into the food that's being fried, it should be fried at the temperature where it does not soak through, else it becomes quite unappetizing. It is normal that you get a lot of oily vapor when frying, especially at higher temperatures, you cannot prevent that. A splatter screen is sometimes used, but it is not suitable for wokking, because you can't move the foodd items with it. 

As for what is the right amount of oil, I can't help you exactly because I don't do much wokking on my own. But I suppose good temperature control will indeed use up more fat than modern Western cooks tend to use. 

There is a related question of a user complaining about oil splatter, and the conclusion is the same: you have to live with it. Good way to prevent grease build up in kitchen?.