In spite of the small size of the bath, its furnace was skilfully engineered: clearly it was designed and built by a highly specialised team with solid expertise. The furnace supplied hot air for the floor heating system (hypocaustum), ensured intense heat in a separate chamber above it for water-heating vats, and generated hot water vapour in yet another chamber connected to the hot bath room, while smoke escaped through an elaborate system of chimneys embedded in the walls.