Cigarette smoke detector?

Question

Do it yourself

Are there any?
The problem is that the downstairs neighbor comes out on the balcony to smoke. In the summer the windows/windows are open, as a result, the smell of smoke appears in our room with a balcony. And this is our baby. Talking to him is useless - "Our territory, we do what we want." I will remove this selfishness. The method is clear.
I need an understanding that they continue/stopped smoking. To control constantly, and even more so at night (which happens often), of course, is not possible.
What sensor options are available? It seems that different types are possible:
- to change the transparency of the air. Are they sensitive to airborne dust?
- chemical type - change in the conductivity of the sensor surface in the presence of certain substances in the air.
Does anyone have experience of using it? The main question is sufficient sensitivity to smoke. Reliability of operation.

Answer 1

It seems to me that arduino with such a sensor is enough here .

Answer 2

if it `s not a secret; - and what function will the electronic device perform? pour a bucket of water on a neighbor's head? ;)

Answer 3

Nothing will help. The smoke enters the apartment strongly mixed with air, so if the sensor is triggered, then this happens already strongly after the appearance of an unpleasant odor. Believe me, I have tried everything, down to a super-tech sensor from America called freshairsensor.
The output is a system of a fan and a carbon filter.