we are getting ready to build a hatcher, and I have a few questions about placement of a few of the items since looking through the 'coops' section has shown a lot of different setups without much follow-up. for starters, we will be using a styrofoam cooler, cutting out the lid and putting plexi-glass in for the viewing window. We have a 3.1in x 3.1in computer fan we will be using, a lightbulb, and a water-heater (I think) thermostat. do we need to mount the fan IN the wall of the cooler? I saw examples in the 'incubators' page where if was installed (like a regular forced-air) in the wall, and others where it was simply set in the inside. should I place the fan so it blows ACROSS the lightbulb, ABOVE the lightbulb, or at the opposite end of the cooler from the lightbulb? do we place these items (bulb and fan) in the MIDDLE, the BOTTOM, or closer to the TOP of the cooler? I've seen alot of DIYs where they are at the bottom, but the heat-source in our hava bator is at the top. I'll pobably have a few more questions, but I'm sure this is enough to start with.