Install Instructions
IM-PR 566442 1114 (Design Manual)
100
Location
Snowfall
Hours per
Year
Snow-Free
Area Ratio
A
r
Heat Fluxes Not Exceeded During Indicated Percentage
of Snowfall Hours from 1982 through 1993, Btu/h-ft²
b
75% 90% 95% 98% 99% 100%
Lexington, KY 50
1
0.5
0
81
49
16
108
65
30
123
74
39
150
85
46
170
95
55
233
197
162
Madison, WI 161
1
0.5
0
99
61
23
138
82
39
164
98
60
206
129
91
241
163
113
449
245
194
Memphis, TN 13
1
0.5
0
106
75
40
141
96
75
172
115
76
200
118
90
206
130
97
213
157
123
Milwaukee, WI 161
1
0.5
0
101
62
23
135
83
46
164
101
68
196
128
98
207
147
120
431
246
239
Minneapolis-
St. Paul, MN
199
1
0.5
0
119
73
23
169
99
45
193
114
61
229
138
91
254
154
113
332
287
245
New York, NY,
JFK Airport
61
1
0.5
0
91
63
38
134
93
68
164
118
86
207
145
113
222
164
133
333
325
316
Oklahoma City, OK 35
1
0.5
0
117
72
24
168
101
46
215
123
68
248
133
78
260
144
113
280
208
190
Omaha, NE 94
1
0.5
0
108
65
23
148
89
38
189
105
60
222
128
90
259
135
100
363
186
136
Peoria, IL 91
1
0.5
0
95
58
23
139
83
38
166
99
53
201
119
76
227
130
92
436
250
228
Philadelphia, PA,
International Airport
56
1
0.5
0
94
65
38
129
90
63
154
112
79
208
162
111
246
185
150
329
267
225
Pittsburgh, PA,
International Airport
168
1
0.5
0
83
51
16
125
75
31
159
94
46
194
111
68
219
129
77
423
216
136
Portland, ME 157
1
0.5
0
120
76
39
168
108
67
195
132
90
234
168
130
266
199
152
428
376
324
Portland, OR 15
1
0.5
0
50
39
23
78
55
45
102
81
60
177
114
78
239
130
102
296
199
128
Rapid City, SD 177
1
0.5
0
139
78
16
203
111
30
252
132
38
312
164
53
351
183
65
482
245
179
Reno, NV 63
1
0.5
0
50
36
23
72
55
45
89
75
68
116
105
91
137
115
113
191
172
159
Salt Lake City, UT 142
1
0.5
0
52
39
30
77
62
60
89
76
75
110
96
89
120
104
104
171
171
171
Sault Ste. Marie, MI 425
1
0.5
0
112
66
23
153
88
37
183
104
47
216
125
68
249
142
83
439
239
188
Seattle, WA 27
1
0.5
0
56
45
37
107
72
52
138
97
75
171
122
96
205
133
123
210
175
151
Spokane, WA 144
1
0.5
0
67
45
23
98
61
37
116
73
45
141
84
54
159
95
67
227
145
112
Springeld, MO 58
1
0.5
0
110
70
32
155
95
54
179
117
76
215
142
115
224
171
129
292
240
227
St. Louis, MO,
International Airport
62
1
0.5
0
97
66
31
147
90
53
170
105
68
193
126
97
227
144
104
344
269
194
Topeka, KS 61
1
0.5
0
102
64
23
153
92
39
192
110
52
234
132
68
245
139
84
291
185
167
Wichita, KS 60
1
0.5
0
115
71
24
163
96
45
209
116
57
248
137
75
285
153
83
326
168
158
Table 5-2. Frequencies of snow-melting surface heat fluxes at steady state conditions.
a
(Cont.)
Does not include back and edge heat loss.
a. Heat fluxes are at the snow-melting surface only. See text for calculation of back and edge heat loss fluxes.
b. Multiply values by 0.2931 to convert to W/ft²