Graphics card fan installing in incubator

I bought a still air Little Giant incubator & wanted to install a fan. I recently dabbled in graphics card replacement for my desktop....twice even & just so happened to have saved at least one. I knew the fan still worked so today i spliced it to an old charger i had. I couldnt find any sticker anywhere on fan or graphics card for voltage but i used a 10v charger, as my understanding is you want 12v ideally but 10v is okay, just slightly slower fan speed?

Plugged in, tested & working. Now my main question is it already had a "spacer" so it wont sit directly against foam....but i saw several pics/videos of people adding a shield to space out air flow.... I noticed in testing that it seems to blow out side anyways.....im assuming this is due to it being a graphics card fan instead of a regular computer fan....so can i skip the shield?

If not i was thinking of taping on a piece of heat resistant plastic(that came with my steel utility shelves). Or maybe just fabric screen? What do you think? Ive still got to finish installing on the bator

This was "spacer" so this part against top of bator?



Side view. It sorta has a shield already.