Solo was designed with a unique air path to ensure zero convection and therefore zero heat emission whenever the air impeller was stationary. This cleverly eliminates the use of water valves, and this was one of the primary objectives of the Solo design.
The unique selection of, and unconventional use of a backward curved impeller achieves this objective.

Furthermore, the lack of direct line of sight to any potential source of acoustic noise was facilitated by facing the inlet of the impeller to the mounting surface.
For noise data, please refer to the Solo Performance Technical Brief.