I had a question about using truck filters for my DC. Specifically I was wondering if any engineers or anyone who has used them can speak to the issue of direction of airflow. I have a Delta 760 and am looking to get a MERV15 or better filter attached to it. One thing I’ve read on these forums is that truck filters are manufactured to have air blown from outside to inside. I don’t even know if that’s true and if it is, that it matters. Does anyone know anything about this? Is it a real issue? It seems to me that the Donaldson filters are standard truck filters that work well with our DC generally.