It really depends what you’ll do with it. The HepaZone M is more robust, easier to clean/decontaminate and has 2 shelves (which are really more useful than you think!).
On the other hand, our HepaZone S is way more convenient if you need to carry it to different facilities/sites since it can be dropped as low as 10’’ and is 40% lighter.
As for the fan, they both can be delivered with our cordless HepaNomad which has 16h of autonomy.