Since 30 years, over the world, antifrost windmachine are generally two bladed  are really noisy 

The main objective of SOA is to reduce this noise in order to protect neighbours

 After 10 years research, a first prototype was tested in Cognac in September 2020, noise has been reduced from 10db at 250 m

technologie d'hélices agricole pour tour anti gel


Compared spectral noise analysis between a 2 bladed windmachine and SOA rotor



P1 2 bladed at 120m


P1 S.O.A. fan at 120m

Helices 4 pales pour tour anti gel

This fan can be fit up on any kind of existing 2 bladed machine


A major technological evolution..


The origin fan nois provid from several factors :


 Thickness noise

 Loading noise

Broadband noises

Interaction between vortex and blades

High speed impulse noise



Working on several of these factors and with a straight combination of those, S.O.A. has reduce drastically the noise.