Document Gm6NOGeJqE255ovVoymmxGqnV

HEATING VENTILATING AIR CONDITIONING GUIDE 1941 REFERENCES Commercial Drying Apparatus, by L. P. Dwyer (A.S.H.V.E. Transactions, Vol. 22 1916, p. 479). Artificial Drying with Special Reference to the Use of Gas, by G. C. Shadwell (A.S.H. V.E. Transactions, Vol. 23, 1917, p. 231). Drying by Evaporation, by F. R. Still (A.S.H.V.E. Transactions, Vol. 23, 1917 p. 255). High Temperature Drying, by Burt S. Harrison (A.S.H.V.E. Transactions, Vol. 24 1918, p. 7). The Temperature of Evaporation, by W. H. Carrier (A.S.H.V.E. Transactions Vol. 24, 1918, p. 25). Commercial Dehydration, by J. E. Whitley (A.S.H.V.E. Transactions, Vol. 26 1920, p. 551). Drying as an Air Conditioning Problem, by A. W. Lissauer (A.S.H.V.E. Trans actions, Vol. 27, 1921, p. 251). A Chronological Survey of Drying and Driers, by J. E. Bolling (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, October, 1921, p. 715). Calculations for Drying Design, by Grosvenor (Transactions, American Institute Chemical Engineering, 1908, p. 184). The Rate of Drying Solid Materials, by J. Lewis (Industrial Engineering Chemistry, 1921, p. 427). Adiabatic Drying of Hygroscopic Solids, by A. M. McCready, and W. L. McCale (Transactions, American Institute Chemical Engineers, 1933). Lignite Drier, by Lavine & Sutherland (Chemical and Metallurgical Engineering, July, 1929). Enameling Oven Economy, by B. S. Harrison (Fuels & Furnaces, February. 1931). Powdered Yeast Prepared by Spray Drying, by A. W. Farrell, (Food Industry, December, 1931). Factors that Influence Drier Performance, by A. Weisselberg (Chemical and Metallur gical Engineering, August, 1932). Principles of Drying Lumber and Humidity Diagram, by H. D. Tiemann (Forest Service Bulletin 104, 1912). Symposium on Drying. Articles by W. K. Lewis, W. H. Carrier, A. E. Stacey, Jr. and R. S. Fleming, R. G. Metz, G. B: Ridley, C. O. Lavett, D. J. Van Marie (Journal Industrial Engineering Chemistry, May, 1921). The Drying of Solids, by T. K. Sherwood (Bulletin Massachusetts Institute Technology Nos. 237, 247 and 258). Air Conditioning and Engineering, American Blower Co. Combustion (American Gas Association, 3rd edition, 1932). Die Trockentechnik, by M. Hirsch (Julius Springer, Berlin, 1932). Drying (Kent's, Mechanical Engineers Handbook, 10th edition, 1923; 11th edition, 1936). Drying, by W. H. Carrier (Marks', Mechanical Engineers Handbook, 3rd edition, 1930). Drying, by Perry (Chemical Engineers Handbook, 1934). Drying by Means of Air and Steam, by E. Hausbrand (D. Van Nostrand & Co., 1901). Drying in Industrial Plants, by J. O. Ross. -j Elements of Chemical Engineering, by Badger and McCabe (McGrawHil! Co., 1931). Fan Engineering, Buffalo Forge Co. Fuels and Their Combustion, by Haslam and Russell (McGraw Hill Co., 1926). Heat Transmission, by W. H. McAdams (McGraw Hill Co., 1933). Modern Drying Machinery, by H. B. Grenshaw, London, 1926. Principles of Chemical Engineering, by Walker, Lewis. McAdams (Chapters on Evaporation, Humidity and Drying, 2nd edition, McGraw Hill Co.). The Kiln Drying of Lumber, by A. Koehler and R. Thelen, New York, 1926. The Kiln Drying of Lumber, by H. D. Tiemann (Lippincott, 1920). 716 Chapter 41 NATURAL VENTILATION Wind Forces, Stack Effect, Openings, Windows, Doors, Sky lights, Roof Ventilators, Stacks, Principles of Control, General Rules, Measurements, Dairy Barn Ventilation, Garage Ven tilation VENTILATION by natural forces, supplemented in certain cases by wind-actuated devices, finds application in industrial plants, public buildings, schools, dwellings, garages, and in farm buildings. The natural forces available for the displacement of air in buildings are (a) wind forces, and (b) the difference in temperature between the air inside and outside the building, or a combination of the two. The results that are obtained by natural ventilating systems are variable, as they depend on wind action and temperature difference. The arrangement and control of ventilating openings should be such that the two forces act cooperatively and not in opposition. WIND FORCES In considering the use of natural wind forces for the operation of a ventilating system, account must be taken of (1) average and minimum wind velocities, (2) wind direction, (3) seasonal, daily and hourly varia tions in wind velocity and direction, and (4) local wind interference by buildings, trees, etc. Table 1, Chapter 6, gives values for the average summer wind velocities and the prevailing wind directions in various localities throughout the United States, while Table 2, Chapter 5, lists similar values for the winter. In almost all localities the summer wind velocities are lower than those in the winter, and in about two-thirds of the localities the prevailing direc tion is different during the summer and winter. While average wind velocities are seldom below 5 mph, there are many hours in each month during which the wind velocity is from 3 to 5 mph, even in localities where the seasonal average is considerably above 5 mph. .There are relatively few places where the hourly wind velocity falls much below 3 mph for more than 10 daylight hours per month. Usually a natural ventilating system should be designed to operate satisfactorily with a wind velocity of 3 to 6 mph, depending on locality. 717