Visitors inspect a large AL-KO AT4 rental air handling unit

Photo: Mariusz Młynarczyk / CloudAir.tech

Visitors look into an open section of a long two-tier AL-KO air handling unit from the modular AT4 series, with a large louvred intake at its end. A panel on the casing reads "MIETE MICH! RENT ME!" and strips of moss line the top. The unit sits on a wooden floor beneath an upper deck.