<p>I have mounted two radial fan on my printer as a part cooling solution.</p>

<p><a href="https://i.stack.imgur.com/MTeZ5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/MTeZ5.png" alt="radial blower fan"></a></p>

<p>As you can see, the fan has input on the left side and blows air down. Does a mirror construction exists? With outlet on the right.</p>

<p>I can even print my own casing, but I'm not sure if the fan will work, if I change the rotation direction.</p>

<p>I'm using this print cooling fan duct: <a href="https://www.thingiverse.com/thing:1850163" rel="nofollow noreferrer">https://www.thingiverse.com/thing:1850163</a></p>

<p>The fan on the right side has the opening facing the hotend, and there is not much space, so the impeller can catch on wiring etc. If the right fan had opening to the right, there would be no such problem.</p>

https://www.alibaba.com/product-detail/120mm-Small-Squirrel-Cage-Exhaust-Plastic_653850349.html?spm=a2700.7724857.normalList.14.23834341IiKFAu&s=p
After quite a bit of searching the above link from Alibaba was all I could find. I suspect that they don't make them like that because of the direction of the rotation of the blades. Perhaps they are made so that the rotor can be swapped around if necessary.
(
https://i1.wp.com/www.homeintheearth.com/wp-content/uploads/2012/11/CentrifugalFanTypes.jpg
)
The different curving of the blades affects either the volume or the pressure of the airflow (or both).
Alternatively how about one that is more agnostic:
https://www.amazon.com/2Packs-Wathai-40x40x10mm-Brushless-Centrifugal/dp/B07RNZF97F/
Or just 3d print your own housing!