Experts,

Can't find answer for basic question of basement ventilation method: do you vent air out to outside (with fan in the wall), or you suck it in from outside (also w ith a fan in the wall)?

Or it doesn't matter as long as air inside basement gets displaced somehow ?

Thanks all!

If it is a bath, you always vent out. Radon is vented out. Air for combustion is vented into the heater and the exhaust is vented out. Anytime you vent in or out, you have to temper the air, heat in winter AC in summer. What exactly are you trying to do?