Document M4Ek3ZXm0Ky67goNmzQw709Xy

American Society of Heating and Ventilating Engineers Guide, 1932 Subject Garages Title Code for Heating and Ven tilating Garages Wren Adopted June, 1929 Reference A.S.H.V.E. Journal, May, 1929, p. 63 Heat transmission through walls Standard Test Code for Heat Transmission through Walls January, 1928 A.S.H.V.E. Transactions, Vol. 34, 1928 Minimum requirements Code of Minimum Require ments for Heating and Ventila tion of Buildings, Edition-1929 June, 1925 A.S.H.V.E. Codes Pitot tube Code for Use of Pitot Tube January, 1914 A.S.H.V.E. Transactions, Vol. 20, 1914, p. 211 Radiators Code for Testing Radiators January, '1928 A.S.H.ViE. Transactions, Vol. 33, 1927. Reprints available . Radiators (concealed) Code for Testing and Rating Concealed Gravity Type Radiation (Steam Code) January, 1931 Heating, Piping and Air Conditioning, August, 1931 Unit heaters Standard Code for Testing and Rating Steam Unit Heaters'1 January, 1930 A.S.H.V.E. Transactions, Vol. 36, 1930. Reprints available Adopted jointly by the Industrial Unit Healer Association, and the A.S.H.V.E. The following Codes and Standards have been endorsed or approved by the American Society of Heating and Ventilating Engineers: Subject Chimneys Title Sponsored bt Reference Standard Ordinance for Chim National Board of Chapter 14, ney Construction Fire Underutriters Guide, 1931 Piping systems Identification of Piping Systems^ American Society Heating, Piping and of Mechanical Air Conditioning, Engineers July, 1929 . Warm air furnaces Standard Code Regulating the National Warm National Warm Air Installation of Gravity Warm Air Heating As Heating Association, Air Furnaces in Residences sociation Columbus, Ohio ^Adopted November. 1928. Sponsored by (1) American Society of Mechanical Engineers, (2) National Safety Council. GREENHOUSE HEATING It is important that the heat shall be diffused evenly, that there shall . be no high-velocity air currents, especially for flowers, and that no rapid temperature fluctuation shall be permitted. 546 Chapter 40--General Information Steam and hot water systems both are used in greenhouse heating. Electrically propelled unit heaters have been used with good results. Unfortunate results occasionally are encountered with all of these dif ferent kinds of apparatuses. Table 1 gives the usual temperatures required in greenhouses. The heat losses from greenhouses are computed the same as are the heat losses from other types of buildings. The service is for 24 hours per day, and the peak demand occurs when the weather is cold and there is no sunshine, as at night. Leakage of air through cracks in the glass frames is not serious since in cold weather these freeze due to condensation, and seal tightly with ice. The boiler in a greenhouse must always be selected on the basis of the heat demand and will seem large in proportion to the square feet of radiation, since greenhouse radiators or convectors usually Table 1. Usual Temperatures Required in Greenhouses Kind of Vegetation Violets.... ........................................... Camelias._........................................ Azaleas.............................................. Lettuce.............................................. Cool Palm Houses.......................... Carnations........................................ General Purposes............................ Roses...... ........................................... M.ushrooms.......................... ........... Forcing Houses............................... Conservatories................................ Orchid Houses................................. Fern Houses.................................... Peach House.................................... Vinery.... ........................................... Early Tomatoes and Cucumbers. Tropical Palm House..... .............. Temperature Required. Dbg. Fahr. 40 to 45 50 to 55 55 to 60 60 to 65 65 to 70 are highly efficient. The piping, where direct heaters are used, is designed usually with a view to the kind of plants to be grown, though there is some tendency to use side wall and free hanging overhead heating surface in preference to piping under the plant benches. It is probable that there are more low-pressure steam heating systems in greenhouses than any other kind of system. It is highly desirable that with such plants there shall be vacuuirrpump returns, with thermostatic heater traps. It is important, whatever the type of system, that the heating surface or out-put be well subdivided, so that no matter how.much or how little heat shall be needed, just enough and no more than enough can be delivered. The heat must be distributed just as evenly over the whole area of the greenhouse as though all" of the output were being delivered. One recommendation is that the heating surface be subdivided and provided with valves in increments of not exceeding 10 per cent. 547 1