Document b55Jmv8vRxXGGwjrOraGMDmpZ

American Society of Heating and Ventilating Engineers Guide, 1929 Column B.--Dust determinations are next made at stations 1, 2, 3 and 4, and the count of particles per cubic foot recorded from each station. The scale of the chart is arranged for a direct reading dust counter. If some other type of instrument is used, a correction factor is, of course, necessary. Column C.--Culture plates are next exposed to determine the bacterial content of the air. One plate is exposed at each station for two minutes, incubated, and the colonies that develop are counted and recorded for each plate. The average of all plates is plotted on the chart. Column D.--Odor determinations are made of the room as a whole. The observer should go outside of the room or preferably outside of the building for a few moments previous to making the test. He then enters the room quickly, and makes his determinations of the air in the classroom by means of the olfactory sense, recording the results whether perfect, very faint, noticeable, etc., in accordance with the following table. \ 100% Perfect 95% Very Faint Freedom from Odors 90% Faint 85% 4 Noticeable 80% Distinct 75% Decided 70% Strong An Odorometer consists of a case of six vials each containing an odor substance in varying strength. It adds materially in classifying and standardizing* odor perception. Its use, however, is not imperative. . Column E.--Samples of air are next taken at each station, and ..later analyzed for carbon dioxide, and results of this analysis plotted in Column E in parts in 10,000. Column F.--Distribution of the air in the room is determined from the CO2 analysis . taken at the various stations. v 486 Chapter XXXIV--Codes and Standards of A. S. H. & V. E. The following example illustrates the method of making the calculation: Stations 1_... 2..... 3...... 4..... COs Stations Variations from the Average 11.1 111.1 - 10.2 = 0.9 9.4 2...... 10.2 -- 9.4 -to 0.8 10.4 3...... 10.4 - 10.2 = 0.2 9.9 4....... 10.2 - 9.9 = 0.3 Total 40:8 Average 10.2 Total Average 0.55 X 100 10.2 = 5.4 per cent of variation. 100 -- 5.4 = 94.6 = final per cent of distribution. 2.2 0.55 fix*--. TiMPcmruez Dim mens mm / X J 4 .3 6 7 $ 9 to test noor 77g FttX fSX NOTION OUT MCram oooxs 1 n/rm pare mrw ttwraej CO, tmf woort cr.M. amur tmf moan cr.M. // /* IS .... 74 PRiMner jcnsc inuxsnck______________________________Narco. nOLOoajpima ms/coi onrrr mono, rut ocafanr TOTfU. ax SUPPLY BY CO. nix Jixnr mt ocajfmrer co. .* * * MN at uSTraunoH i WKiom m . TYPC NSCfl LUKN&' xena^aicMTOfr fUotmanenxacN Mimroto TYPC. ; n' nose*. meta *n wmJft to. TB*T CMtCKO IT mx toMl Fig. 3. Data Sheet for Synthetic Air Chart Test After- the tests have been made as described, the observer completes his test by a study of air motion and air currents. This is done by liberated puffs of ammonium chloride in different locations in the room with a suitable apparatus. Observations of the velocity and direction of travel of these small artificial smoke clouds add materially in obtaining a true conception of the velocity and general behavior of the air currents in the room. Plotting the Test Data The results of the tests are plotted in each' column as previously described. The following data from the test illustrated on the chart on page 485 will make the entire procedure clear: Average Dry Bulb temp. 75 deg.--Wet Bulb temp. 59.7 deg.--Effective temp. 67.4 deg. Effective temp. Dif. 3.4 deg.--Plot in Column A. . Aver. Dust Count for 4 Stations---7000 particles per cu. ft.--Plot In Column B. Aver. Bacteria for 4 Stations -- 3.5 --Plot in Column C. Aver. Odors Percentage -- 90 percent --Plot in Column D. Averi CO2 -- 10.2 --Plot in Column E. Distribution Per Cent -- 94.2 percent --Plot in Column F. 487