intake and exhaust fans placement

So I have a intake fan sucking straight from outside about a foot off the ground blowing towards the middle of the room through the lover part of the plants, and I exhaust fan with a small duct sucking from the top middle if the room straight outside. Is this a good way to go? I get quite a bit of powdery mildew could this be a reason why?

powdery mildew is coming from spores entering your grow room and a high humidity giving it the environment it needs, it also spreads quickly. Start by reducing your humidity and getting rid of infected leaves. Have fans around the room keeping the air constantly agitated makign it harder for it to take hold. If its in veg or early bloom spray them down with a solution designed for PM. Then maintain every week or so with Neem.

I personally only use a fan sucking out air and an vent line bringing in fresh air without a fan. The negative pressure or the fan sucking out will pull in the air at the perfect balance.

Use pantyhose to cover the both end of the incoming vent.

Thanks very much, for the info so I have a dehumidifier and everything is setup right, but what you said got me thinking cause my air intakes have no covers or nothing just straight air from outside definitely gonna pick up some pantyhose tomorrow and get it covered. And I live in the country so probably more likely to bring in mold then the city?