NHVRYGray posted:I'm in central NC, humidity is getting to be an issue now until mid/late October. My trains are in my shop which is very tight, housewrap/sheeting/closed cell foam/fiberglass/sheetrock.
I have mini split AC and heat and must keep dehumidifiers running, I like to keep at 40%. I read all about air exchange and get the principle, one thing no one mentions is pollen. Air going out from somewhere must draw air in from somewhere. What do you do about pollen? It has been so bad this year that there has been a yellow fog at times and after two hours outside, your car looks as if some dumped sulfer on it. I don;t use a fan or open windows anymore because of this knowing the house and contents would turn yellow inside.w is the pollen kept at bay when exchanging air?
How is the pollen controlled - kept at bay when using an air exchange system.
Residential doesn't usually use a fresh air exchange outside of combustion chambers; mostly only large commercial /industry systems use air exchange on the conditioned air.
The exchange of lots of outside air just puts a heavier load on a small system. It is usually more efficient to not let any air from outside get in .... too bad we can't survive without fresh air.
The vent at the roof peak grates, eves, and foundation gaps is about it on most homes.
You can fit a furnace filter mount over vents, just make sure the filter's grade won't resrict the expected flow there. (I.e. are your vents big enough to do it without concern, or are they barely big enough for the home? Big vents can accept a very good filter, small ones would need a looser weave.) With an old hvac system or well sealed area, the amount of fresh air in, is more important (for breathing AND combustion reasons.
There are many good reasons you need be certified to work HVAC. If your aren't sure what, how, and why, make that phone call to a pro and discuss their suggestions. That's usually free 
