Hi @crysys ,
The intelligent control aspect of this shield is only something I have started to think of lately.
For energy efficient houses they require an energy recovery ventilator / heat recovery ventilator. These are typically replacing the air in the home 24/7 by sucking in air from the outside.
Without a way to detect the air quality you could be worse off than your neighbour in his 100 year old house.
If a truck/2-stroke motorbike drives past or someone uses a leaf blower or you are in the city during rush hour you could be breathing in those fumes indoors.
Using this shield you could detect those (with the particle counter) and turn off the house intake fans for 2 hours until the fumes have gone. Just having the sensor near the intake fans would be good enough to detect that quickly.
Without a sensor you can improve the situation somewhat with timers if you measure the air outside your house and turn the fans off during rush hour, but its definitely not as accurate when stat holidays / events in the city happen and traffic patterns change.