Document MJX6op85LVxL57BmmZyXg23zM

HEATING VENTILATING AIR CONDITIONING GUIDE 1942 REFERENCES Commercial Drying Apparatus, by L. P. Dwyer (A.S.H.V.E. Transactions, VoI. 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, VoI. 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, 193i). Drying by Means of Air and Steam, by E. Hausbrand (D. Van Nostrand & Co., 1901). Drying in industrial Plants, by J. O. Ross. Elements of Chemical Engineering, by Badger and McCabe (McGrawHill Co., 1931). Fan Engineering, Buffalo Forge Co. Fuels and Their Combustion, by Haslam and Russell (McGrawHill Co., 1926). Heat Transmission, by W. H. McAdams (McGraw Hill Co., 1933). Modem 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). 760 Chapter 42 NATURAL VENTILATION Wind Forces, Stack Effect, Openings, Windotvs, Doors, Skylights, Roof Ventilators, Stacks, Principles of Control, General Rules, Measurements, Dairy Barn Ventilation, Garage Ventilation VENTILATION by natural forces, finds application in industrial plants, public buildings, schools, dwellings, garages, and in farm buildings. The natural forces available for moving air into, through and out of buildings are: (a) wind forces, and (b) the difference in temperature between the air inside and outside a building. The air movement may be caused by either of these forces acting alone or by a combination of the two, depending upon atmospheric conditions, building design and loca tion. The ventilating results obtained will vary, from time to time, due to variation in the velocity and direction of the wind and the heat gener ated in the building. The arrangement, location, and- control of the ventilating openings should be such that the two forces act cooperatively rather than in opposition. WIND FORCES In considering the use of natural wind forces for producing ventilation, account must be taken of: (1) average wind velocity, (2) prevailing wind, direction, (3) seasonal and daily variations in velocity and direction, and (4) local wind interference by nearby buildings, hills or other obstructions of similar nature. Values are given in Table 1, Chapter 7 for the average summer wind velocities and the prevailing wind directions in various localities through out the United States, while Table 2, Chapter 6, 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 direction is different during the summer and winter. While the tables give no average velocities below 5 mph, there will be times when the velocity is lower, even in localities where the seasonal average is con siderably above 5 mph. There are relatively few places where the velocity falls below one half of the average for many hours per month. Con sequently, if the natural ventilating system is designed for wind velocities of one-half of the average seasonal velocity, it should prove satisfactory in almost every case. i 761