Actually i have 2 identical 4'' air intakes with those homemade filters on them that go into the cabinet. it was just hard to get a picture with both of the intakes in it. so in other words two 4'' filtered intakes = one 4'' air intake with no filter. Yeah i was worried about the temp rising too but i checked it every couple of hours and the temp remains unchanged, about 80 degrees during the day and 72 at night.