Weather Data - Hours available for evaporative cooling:


 Location:  Des Moines, IW      Elev: 938    Lat: 41/32N  Long:93/36W

Mean Frequency of occurrence of Dry Bulb Temperature with Mean Coincident Wet Bulb Temperature for each Dry Bulb Temperature Range:

                               ASHRAE  design Dry Bulb and Mean Coincident Wet Bulb:
                          
   1% Scale:    2.5% Scale:    5% Scale:            Design Wet Bulb:
                           Db       Wb       Db      Wb        Db      Wb           1%     2.5%     5%
                            94        75        91       74         88        73           78       77         75
  
Average number of hours within each temperature range and discharge temp. (see notes):

January - April Weather Data

Temp Range: Deg (f) January February March April Total
Low High Mean Hours Wb Tout Hours Wb Tout Hours Wb Tout Hours Wb Tout  
115 120 117.5                          
110 114 112                          
105 109 107                          
100 104 102                          
95 99 97                          
90 94 92                          
85 89 87                   1 65 66.1 1.0
80 84 82                   7 64 64.9 7.0
75 79 77             1 59 59.9 14 61 61.8 15.0
70 74 72             4 55 55.9 27 58 58.7 31.0
65 69 67             6 53 53.7 43 56 56.6 49.0
60 64 62       1 53 53.5 12 51 51.6 60 53 53.5 73.0
55 59 57 1 45 45.6 3 46 46.6 21 48 48.5 80 50 50.4 105.0
50 54 52 5 44 44.4 10 44 44.4 31 44 44.4 98 46 46.3 144.0
45 49 47 9 41 41.3 21 41 41.3 48 41 41.3 110 42 42.3 188.0
40 44 42 28 37 37.3 40 38 38.2 81 37 37.3 96 38 38.2 245.0
35 39 37 63 34 34.2 80 34 34.2 113 34 34.2 92 34 34.4 348.0
30 34 32 98 30 30.1 135 30 30.1 170 30 30.1 68 30 30.1 471.0
Total hours Temp out over 40(f) 15   35   123   440 Total hours for this period 613.0

Note: 1.  Db = Dry Bulb(f) temperature, Wb = Mean coincident wet bulb temp (f).  Tout = Discharge Temperature (f).   Only hours where discharge temp is over 400(f) is included in total hours available for evaporative cooling.

May - August Weather Data

Temp Range: Deg (f) May June July August Total
Low High Mean Hours Wb Tout Hours Wb Tout Hours Wb Tout Hours Wb Tout  
115 120 117.5                          
110 114 112                          
105 109 107                          
100 104 102             2 76 77.3       2.0
95 99 97       3 77 78.0 9 76 77.1 7 74 75.9 19.0
90 94 92 1 69 70.2 18 74 74.9 29 75 75.9 26 74 75.7 74.0
85 89 87 10 69 69.9 45 72 72.8 75 73 73.7 55 73 74.5 185.0
80 84 82 29 67 67.8 86 70 70.6 118 71 71.6 94 71 72.3 327.0
75 79 77 57 64 64.7 111 67 67.5 144 69 69.4 135 69 70.2 447.0
70 74 72 87 61 61.6 131 65 65.4 166 67 67.3 160 67 68.0 544.0
65 69 67 110 59 59.7 137 62 62.5 126 64 64.2 138 64 64.9 511.0
60 64 62 137 56 56.3 102 58 58.2 59 59 59.2 87 59 59.9 385.0
55 59 57 129 52 52.3 57 54 54.2 15 55 55.9 31 55 55.9 232.0
50 54 52 94 48 48.2 22 50 50.1 2 51 51.8 10 51 51.8 128.0
45 49 47 53 44 44.2 5 45 45.4       1 46 46.8 59.0
40 44 42 26 39 39.2                   26.0
35 39 37 8 34 34.4                   8.0
30 34 32 3 31 31.6                   3.0
Total hours Temp out over 40(f)     717   745   751 Total hours for this period 2913

September - December Weather Data

Temp Range: Deg (f) September October November December Total
Low High Mean Hours Wb Tout Hours Wb Tout Hours Wb Tout Hours Wb Tout  
115 120 117.5                          
110 114 112                          
105 109 107                          
100 104 102                          
95 99 97 1 69 70.4                   1.0
90 94 92 8 71 72.1 1 65 66.4             9.0
85 89 87 20 71 71.8 3 66 67.1             23.0
80 84 82 37 68 68.7 12 65 65.9             49.0
75 79 77 64 65 65.6 26 63 63.7             90.0
70 74 72 93 63 63.5 48 60 60.6 3 59 59.7       144.0
65 69 67 119 60 60.3 72 57 57.5 11 56 56.6       202.0
60 64 62 132 57 57.3 94 55 55.4 26 54 54.4 1 54 54.4 253.0
55 59 57 110 53 53.2 111 51 51.3 39 50 50.4 5 51 51.3 265.0
50 54 52 78 49 49.2 110 46 46.3 61 46 46.3 16 46 46.3 265.0
45 49 47 41 45 45.1 103 43 43.2 76 42 42.3 22 41 41.3 242.0
40 44 42 13 40 40.1 77 39 39.2 95 38 38.2 46 38 38.2 231.0
35 39 37 2 36 36.1 50 34 34.2 111 34 34.2 86 34 34.2 249.0
30 34 32       24 30 30.1 115 30 30.1 123 30 30.1 162.0
Total hours Temp out over 40(f) 716   480   216   44 Total hours for this period 1543
Total hours available for evaporative cooling  

Data published by Premier Industries, Inc., in part from data contained in EcoDyne's Weather Data Handbook no longer in print.  Premier Industries, Inc., provides these data for informational use only.  All reasonable precautions have been taken to maintain integrity in these data however  Premier Industries will not be responsible for it's accuracy.  Any responsibility for the use of this information shall be borne by the user.