Passive Ethernet Hub Setup Wireless Router Outside Along With Biquad Wireless Wifi Dish. Weatherproof Enclosure Idea! Condensation.?

Setup wireless router outside along with biquad wireless wifi dish. Weatherproof enclosure idea! Condensation.? - passive ethernet hub

I,

In planning to build a wireless antenna biquad. I ran the coaxial cable from the antenna around the house with the router, but I've heard that you dB, can lose doing this. So I thought I should have a motherboard WRT54G and into a plastic box and mount it outside. She has the power of passive PoE (Power over Ethernet). As in the concerned, however, is that I have a Vent / mesh fan must be installed inside the enclosure. When the housing completely mesh of 5x5 cm (or sealed 8x8cm) ventilation (a fan), can penetrate the water and somehow condense. What I mean is that condensation inside the box. Thus, in winter water will condense on the inside? I wouldnt want to touch the water in the field, because the router motherboard inside with PoE will be suspended. Is there anything I can do it with what was too cold for the condensation or fill it?

Thank you!
David