always let the weaker fan blow in the stronger fan suck out ..
if you look at my photos the oem fan stayed in place and it is a 110-120cfm fan
my add on fan is a 140 delta ..
see the pipe cleaners with spacers to hold the new fan.
in this photo the weaker oem fan never moved it blows in. the stronger delta sucks out... see how i powered the delta. piggyback on the screw in power supply.
it is a full speed 24/7 plug them uncut new fan into this
i got some of these cheap and cut them
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It's been stated the miner is in an enclosed area. Even if it won't be for long, in it's current situation it makes sense to exhaust out the front, rather than trap and recirculate warm air.
In any event, that could even mean installing it as philipma1957 is showing, then just turning the unit around.