what would happen to the Overboard Exhaust Valve if the right Recirc fan was turned off?
It will open,as the right recic fan as the function of smoke removal and the air pulled by the exhaust fan (cabin and E/E) will go out...instead of being directed around the forward cargo bay for heating..
I'll make a video on my next flight. Absolutely nothing happens to the fuel flow when turning off the recirculation fans. It does however get quieter, because the air is no longer being recirculated!
Please keep your video,the fuel consumption is so small it is useless.
Air is not being recirculated but is circulating....packs provide cabin conditioned air via the passengers center and side walls of the cabin.
Let's just see what boeing engineering has to say.