Mold problem in new kitchen - how to prevent it in the future?

No. The refrigerator has the heat exchanger at the back.

With "PC case fan with power supply" you will find something on Amazon. Either really with a power supply or also a USB connection, which you can plug into any socket with the appropriate small power supply.

However, that will certainly result in some wild tinkering. PC fans mainly come in 80 and 120mm sizes, but there isn’t that much space next to the fridge. And the smaller the fan, the louder it is. You’d have to build something that sucks in air broadly and then pushes it in narrowly, some kind of funnel or something.

Although that will certainly end up as a wild DIY job. PC fans mainly come in 80 and 120mm; there isn’t that much space next to the fridge. And the smaller the fan, the louder it is. You’d have to build something that sucks in air broadly and then pushes it in narrowly, some kind of funnel or something.

The idea was to attach the fans below the ventilation grille to push air in properly.

However, this does not eliminate the cold bridge at the bottom of the walls. Is this a concrete floor?

Is that a concrete floor?

Yes, directly under the click vinyl is the concrete screed

Tempering the wall in the area of the baseboards would also be an option and would specifically address the mold problem (corner of two uninsulated house walls). In the long term, I would otherwise expect that mold could also develop behind the other cabinets in the base area. Search for Fußleistenheizung.