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).
Product data sheet for Burgess Acousti-Pad, a sound absorbent for air-conditioning duct noises.
| Identifier | ExFiles\Box 104\2\ scan0200 | |
| Date | 1st March 1936 | |
| BURGESS ACOUSTI-PAD For Absorbing Duct Noises in Air-Conditioning Systems Burgess Acousti-Pad is the modern noise absorbent for lining air-conditioning ducts. It absorbs the roar of ventilating fans, the sound of rushing air, and inter-room duct noises. Burgess Acousti-Pad is also an efficient thermal insulator for air-conditioning ducts. No other thermal insulation is required in duct sections where Burgess Acousti-Pad is used. The Burgess Acousti-Pad is faced with perforated No. 26-gauge terne plate. The Burgess Acousti-Pad sound absorbent is a 1-in. blanket of Balsam-Wool. Burgess Acousti-Pad is a sound absorbent of unusual construction and performance. It is the ideal acoustic lining for air ducts because its hard, smooth surface offers the minimum resistance to air flow in ventilating systems, and its high acoustic efficiency enables it to blot up duct noises as effectively as a blotter blots up ink. The freedom from odor, even when moist, is an important advantage of Burgess Acousti-Pad. Altogether, it is the most practical sound absorbent for air-conditioning and ventilating ducts. Sound waves, upon striking the perforated metal facing, are not reflected as light waves are, but trickle through the perforations of the Burgess Acousti-Plate like water through a sieve. The illustrations portray this phenomenon. The Burgess Acousti-Plate facing is 10 per cent perforated, yet nearly 100 per cent of the sound energy striking the surface passes through the holes, dissipating itself, through acoustic friction, in the soft pad of Balsam-Wool. The metal facing permits high air velocities without blowing the acoustic material into the air stream. Burgess Acousti-Pad will last as long as any good metal duct. The perforated Burgess Acousti-Plate facing does not corrode. LIGHT REFLECTED LIGHT SOUND PERFORATED FACING SOUND ABSORBENT DUCT Head Restriction Chart Due to Lining Existing Ducts with BURGESS Acousti-Pad Percent Duct Is Reduced in Area Due to 1" Lining of BURGESS Acousti-Pad Restriction Per Ft. of Duct in Inches of Water Air Velocity 800 1000 1200 1600 Feet Per Minute Head Restriction Chart When Burgess Acousti-Pad is installed in existing duct systems, the dimensions of the original duct are reduced by the 1 inch thickness of the acoustic lining. For any rectangular duct, the new core area equals the old dimensions of adjacent sides in inches minus two inches each, multiplied together. For example: An original duct dimension of 10" x 50", or 500 square inches, when lined becomes 8" x 48", or 384 square inches. This represents a reduction of 23.2 per cent. For an air velocity of 1000 fpm, this indicates on the Head Restriction Chart a restriction per foot of duct lining of 0.00022 inches of water. The number of lineal feet of duct lining times 0.00022 would indicate the increased pressure required to circulate the original volume of air through the duct. How to Order Burgess Acousti-Pad Burgess Acousti-Pad is put up in standard packages containing 12 sheets of 34" x 36" Acousti-Plate and 12 sheets of 34" x 36" acoustic Balsam-Wool 1" thick. The standard package contains 98 perforated buttons and 98 self-tapping screws, with instruction sheet for assembly. Shipping weight of standard package, 123 lbs. Splitters for Short Ducts Where the length of duct between a grille and fan does not permit the full length of duct lining required, as shown on the Burgess Acousti-Pad chart on page 3, splitters or divisions may be made to equal acoustically a regular section of duct lining. See Bulletin 114. These sections or splitters consist of two sheets of perforated metal with a 1" thickness of Balsam-Wool sandwiched between the plates. In an oblong cross section of duct, arrange the splitter the long way of the section so as to make a narrow dimension between the splitter and the side walls. Assume this is the least dimension of the duct in inches, and from the Burgess Acousti-Pad chart determine the length to be lined in feet, which must be divided by the number of chambers created by the use of splitter sections in the ventilating duct. Technical Information on Burgess Acousti-Pad Sound Absorption Coefficients (By Dr. P. A.{Mr Adams} Sabine, approved by the Acoustical Materials Association.) At 256 cps 29%, at 512 cps 62%, at 1024 cps 80%, at 2048 cps 79%, average 60%. Heat Insulation Coefficients of the 1" Balsam-Wool blanket (by Dr. J.{Mr Johnson W.M.} C. Peebles of Armour Institute.) Mean Temp. 70°F.{Mr Friese}, Conductivity .246, Conductance .218, Resistivity 4.06, Resistance 4.58. Printed in U. S. A.{Mr Adams} — March, 1936, 10M Licensed under C. F.{Mr Friese} Burgess Laboratories, Inc., Patents BURGESS BATTERY COMPANY GENERAL SALES OFFICES, 111 W. MONROE ST.{Capt. P. R. Strong}, CHICAGO Battery Division—FREEPORT, ILL. Engineers and Manufacturers of Acoustic and Electric Products Acoustic Division—MADISON, WIS. Bulletin 113 Index B5/800 A BURGESS | ||