Can anyone recommend a fan shroud for the bed to aid bridging - like to give it a go.

I3v 8"
Standard Gregs Extruder
E3D-V6 hotend (which has a fan already on the upper part of the block)

Seems to be quite a few designs out there, some good comments, some bad. One with good comments looks like it would be too low for the bed and I would be nervous of it cooling the hot end too much,but I guess this is compensated by the heating staying on longer?

http://www.thingiverse.com/thing:351280