In my first Benchy-attempt I noticed the heavy cooling issues with my mosquito-Bowden tool. Despite that the printer performed as expected. Before I build more tools I want to adress the cooling issues with the first tool so I can implement the cooling Design (Fan powered) in my next tools. I haven't tested the integrated airpump because I don't want to use it for my PLA-Bowdentools. 

Comparison (Datasheet):

If you compare the Airflow to Weight ratio the best options are:

1. Delta BFB04512 (45x45x12mm) with 0.0075 [m³/min] /gr
2. Delta, BFB0412 (40x40x10mm fan) with 0.007 [m³/min] /gr
3. NMB, 4515 (45x45x15mm Turbofan) with 0.005 [m³/min] /gr
4. Micronel, D243 (impeller-Design) with 0.002 [m³/min] /gr

Decision for first Bowden-Setup:

I've redesigned the Bowden-tool and used a Trianglelabs Dragon-Hotend and sticked to the 40x40x10mm fan because of the good airflow to weight ratio and re-oriented the benchy on the buld plate so the fan blows to the overhang section at the front.

With the new setup I was able to print a proper benchy. For now I'm quite happy with the result and I will start testing with some genuine GT2 belts and start machining the currently 3d-printed belt tensioner so it can withstand higher tension forces.