From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison of cooling efficiency and noise levels between different fan designs.
| Identifier | ExFiles\Box 155\1\ scan0142 | |
| Date | 3rd July 1934 | |
| -5- HS{Lord Ernest Hives - Chair}/Std.14/KW. 3.7.34. Fans. The staggered bladed fan to LeC.3766 is equal in cooling efficiency to the standard Ph.II fan and definitely quieter. The American variable pitch fan tested is more efficient from a cooling standard than standard Ph.II fan and is approximately equal for noise - hence we propose to reduce the size of this fan until sufficiently quiet and then re-test it for cooling. HS{Lord Ernest Hives - Chair}/C. S. Steadman. | ||