Man you earn applause for that effort.
Great job.
I am still wondering about your fan.
That type if flew hose is fine...you just need to have a really good fan to force the air out and down that tube efficiently.
The benefits are enormous and you may even be able to bring temps down another 5 degrees or so if your fan isn't quite enuff. A vortex fan would be killer right there :)
I know you have air coming out the other side.....how strong is the flow? Can you light a lighter right in front of it and keep it lit?
You should have a strong air blowing out...strong enuff to keep a lighter from staying lit at least a foot away.