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).
Performance chart for A.C. R.V. cores, plotting heat transfer rate against air velocity for various gap sizes.
| Identifier | ExFiles\Box 149a\3\ scan0164 | |
| Date | 9th April 1936 guessed | |
| NO 340-10 EDCO EFFICIENCY 10 X 10 PER INCH EUGENE DIETZGEN CO. 20 x 55 x 2 1/8 A.C. R.V. CORES CHART #3 Y-Axis: B.T.U./MIN./SQ.FT.FA./100°F T.D. X-Axis: VEL. FT/MIN. Graph Lines: .020 GAP .040 GAP .060 GAP Annotations: 1550 BTU .020 GAP REQUIRES 2080 CFM 1550 BTU .040 GAP REQUIRES 2250 CFM 1550 BTU .060 GAP REQUIRES 2540 CFM | ||