Document ZxoL7ZEaqBvZe68x6EO6dggV

of and 1936American Society Heating Ventilating Engineers Guide, Table 2. Base Temperature for the Degree-Day3 Tips or Buzldino No. or Buildings Analyzed 60 4' 3 2 6 11 12 7 ' 14 8 4 5 .3 2 2 4 3 3 2 8 Temperature F Cor responds to Zero Steam Consumption 66.2 65.8 66.2 65.5 67.4 64.0 64.3 66.5. 68.8 66.9 65.5 64.9 67.6 65.8 64.8 61.2 67.7 67.7 65.2 65.4 66,0 F . ' "i Report of Commercial Relations Committee, 193$ Proceedings, National District Beating Association. Table 3. Steam Consumption for Various Classes of Buildings51 {Heating Season Only) Building Classification No. or Buildings Listed Steam Consumption Pounds per Degree-Dat--65 F Basis*) Per M Cu Ft Per M Sq Ft Per M Btu of Heated of Radiatorc per Hr of 8paoe Surface Heat Loe&b Apartments............................................................. Hotels. ................................. ................................ Retail Stores........................................................... Theatres........................................ .......................... Loft and Mfg......................................................... Department Stores..................... ..................... Garages (Storage)3 ................................ Offices (Total)____ --............................................. Offices (Heating only).......................................... 16 10 12 7 10 18 6 16 7 8 6 14 6 35 35 .1.78 T.46 1.32 1.25 0.96 0.90 0.90 0.89 0.88 0.83 0.58 0.57 0.42. 1.09 0,975 97.5 80.6 64.2 105.5 77.0 80.6 75.0 72.3 45.2 62.2 49.4 ' 60,7' 72.3 70.0 65.4 . 0.359 0.371 0.268 0.498. 0.283 0.238 ____ J. 0:283 0.256 Includes steam.for heating domestic water for heating season only. Mieat loss calculated for maximum design condition (in most cases 70 F inside, zero outside).; . ^Equivalent steam radiator surface. dThe figures are a numerical--not a weighted-average for the several buildingB in each class. Based on zero consumption at 55 F. 514. 29--Chapter Heat and Fuel Utilization expected. For an average figure, the A .G.A. base of 65 F may therefore be safely used, and if greater refinement is desired, the figure for the type of building under consideration can be taken from Table 1. Table 36 gives, the steam consumption per degree-day, expressed in three different ways, for 196 buildings in 14 different classifications. These buildings are divided among 21 different cities in the United States. The steam used for heating the domestic water is included in these figures, but in the case of office buildings, the steam for heating only is also shown. The data are placed on a comparable basis by expressing the steam consumption in terms of pounds per degree-day per thousand square feet of equivalent installed radiator surface^ per thousand cubic feet of heated space, and per thousand Btu of calculated heat loss. Fig. 1. Method of Determining Base Temperature for " Degree-Day Calculations4 The choice of these units of comparison require some explanation. The use of heated space in preference to the gross cubage used by architects' is obviously more accurate for this. purpose. The architect's cubage includes the outer walls and certain percentages of attic arid basement space which are usually unheated. The net heated space is usually about 80 per cent of the gross cubage and can be calculated from the latter if it cannot be measured. The cubical content is somewhat inaccurate as a basis of comparison due to differences in types of construction, exposure, and ratio of exposed area to cubical contents. The use of radiator surface as the basis of comparison has two ob jections. One is that the amount of radiator surface in a building is often either excessive or deficient, and figures for steam consumption based on it are therefore likely to be in error. Another reason is that it is difficult to convert fan coil surface into equivalent direct radiator surface with accuracy. On the whole, the use of radiator surface as the basis of com parison is the least satisfactory of the three methods. `Report of Commercial Relations Committee, 193$ Proceedings, National District Heating Association. The Heat Requirements of Buildings, by J. H. Walker and G. H. Tuttle (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning. December, 1934). 515