As long as the relative humidity stays low like that and the room gets some natural air movement in it. Like walking through or door opening and closing I would not use a fan. Drying too fast may induce harshness. I don't use a fan. I dry plants hanging in a dark room I walk through several times a day and it works well. Takes about 3 days to trim dryness and then I loosley pile them in a wine crate and leave em in the rafters for another 3-5 days. Then to the open bag-closed bag(like a jar, just more)till they are down to 15-20% dry. For my very personal stash I use a nice RX jar for the final cure.