Document 3a5emYn1Vop2LMep70na6ymJ
HEATING' VENTILATING AIR CONDITIONING GUIDE 1940
sheet Fig. 7. Details op Seams
Heating Unit
. l'
Fig. 9. Installation of Easement in Duct Around Obstruction
558
CHAPTER 30. AIR DUCT DESIGN
Table 4. Sheet Metal Gages for Rectangular Duct Construction3
Gash
Width or Duct
SSAH
Runtobckd Scam
26 24 .
22 22
20
Up to 12 in. 13 in. to 30 in.
31 in. to 48 in. 49 in. to 60 in.
61 in. to 90 in,
.
1 1
ih 14 in. x 1% in. ih H in. x 1% in.
alf panels are not cross-broken two gages heavier material should be used.
Table 5. Weights of Sheet Metal Used for Duct Construction
U. S. Std. Gaqb
30 28 26
24 22 20 18
16 14 12 10
Appsoximate Thickness In.
0.0120 0.0149 0.0179
0.0239 0.0299 0.0359 0.0478
0.0598 0.0749 0.1046 0.1345
Sheet Steel
Weight per Square Foot
Ounces
8 10 12
16 20 24 32
40 50 70 90
Pounds
0.5000 0.6250 0.7500
1.0000
1.2500 1.5000 2.0000
2.5000 3.1250 4.3750 5.6250
Galvanized Iron
Weight per Square Foot
Ounces
10.5 12.5 14.5
18.5 22.5 26.5 34.5
42.5 52.5 72.5 92.5
Pounds
0.656 0.781 0.906
1.156 1.406 1.656 2.156
2.656 3.281 4.531 5.781
Table 6. Weights and Thicknesses of Standard Coffer Sheets3 Rolled to Weight
Weight per Square Foot
Ounces
Pounds
Thickness, Inches
Decimal Equivalent
Nearest Fraction
10
0.625
0.0135
Hi
12
0.750
0.0162
%4
14
0.875
0.0189
Hi
16
1.000
0.0216
H2
H18
1.125
0.0243
2
20
1.250
0.0270
Hz
24
1.500
0.0324
Hz
H28
1.750
0.0378
2
32
2.000
0.0432
Hi
36
2.250
0.0486
Hi
40
2.500
0.0540
Hi
44
2.750
0.0594
M.6
He48
3.000
0.0648
56
3-500
0.0756
Hi
64
4.000
0.0864
Hi
Variations from these weights must be expected in practice.
559
Nearest Gage No.
B. & S.
Stubs
27 29 26 27 25 26
23 24 22 23 21 22 20 21
19 20 17 19 16 18 15 17
15 17 14 16 13 15 11 14