[NiceGuyEddie]

I'm an engineer and I also worked for construction contractors for loads of years. once specialty I worked with was in was whole house exhaust and HVAC… they now have systems that suck IN air when you put on your bathroom exhaust fan, for example. a wire is run from the bathroom to another intake fan in another area of the house. the intake fan always exceeds the CFM of the exhuaust fan to help push it out… these systems REALLY help suck the poopie smell out!

anyway….

I couldn't really follow what you are saying with your 1/2, 3/4, 7/8 thing, but keep in mind the exhaust fans in your bathrooms are open passage to the outside, and so is the exhaust fan above your stove. even if they have a "flap" to allow exit air only, it can suck in.

the overflow passage in the rear of your bathroom sinks is also open to an air pipe in the roof. my bathroom sink whistles through the slot in the back of the sink if I have only one slider open like you described!

if your house did not come with an exhaust fan, you probably don't have ample area exhaust (vent) grates in the attic walls (at peaks of the roof) to allow the whole house fan to work optimally. those whirly-bird things help tremendously.

just more to consider when thinking about your dynamics.

andrew said you have too much time on your hands, and so do i - haha - but these are exactly the things i think about when sitting in traffic!

cheers,