fan in enclosure - wiedehopf/adsb-wiki GitHub Wiki
Why a fan is beneficial in sealed outdoor enclosure
Heat moves due to temperature difference
to move heat outside the enclosure, the walls of the enclosure need to be hotter than the outside
with a fan, the differential between the pi / airspy and the air / walls of the enclosure will be reduced to around 10 to 20 C, without a fan the differential would probably be around 50 C or higher
the enclosure has a relatively big surface compared to the pi / SDR, thus even 5 to 15 C differential will be sufficient to move the heat outside