Calculation Pipe Sizing

PIPE SIZE CALCULATION

Frost Coil Reheat Coil Cooling Coil

Supply Flowrate Mass Flow rate Frost Load LTHW Flowrate Pipe Size Reheat Load LTHW Flowrate Pipe Size Cooling Load CHW Flowrate Pipe Size
AHU m3/s Kg/s KW Kg/s mm KW Kg/s mm KW Kg/s mm
1 5.883 6.921176470588 71 0.843 40 113 1.349 50 * 69 2.755 65
2 3.358 3.950588235294 40 0.481 32 64 0.770 32 109 4.325 80
3 1.627 1.914117647059 20 0.233 25 31 0.373 25 * 19 0.762 20
4 4.197 4.937647058824 50 0.601 32 81 0.962 40 * 49 1.965 65
5 2.354 2.769411764706 28 0.337 25 45 0.540 32 76 3.032 65
6 1.640 1.929411764706 20 0.235 25 31 0.376 32 53 2.112 65
7 1.140 1.341176470588 14 0.163 20 22 0.261 25 37 1.468 50
8 0.750 0.882352941176 9 0.107 20 14 0.172 20 24 0.966 40
9 1.140 1.341176470588 14 0.163 20 22 0.261 25 37 1.468 50
10 1.140 1.341176470588 14 0.163 20 22 0.261 25 37 1.468 50
11 0.885 1.041176470588 11 0.127 20 17 0.203 25 29 1.140 50
12 2.820 3.317647058824 34 0.404 32 54 0.647 32 * 33 1.321 50
13 1.764 2.075294117647 21 0.253 25 34 0.404 32 * 21 0.826 40
Sply Flwrte / .85 Q = mc(DT) Q = mc(DT) From CIBSE C Q = mc(DT) Q = mc(DT) From CIBSE C Q = m x (h outside – h offcoil) Q = mc(DT) From CIBSE C

Cp (air) = 1.02 Cp (water) = 4.187 Water @ 75 degC Cp (air) = 1.02 Cp (water) = 4.187 Water @ 75 degC Air on temp °C Db/Wb = 28.5/21 Cp (water) = 4.187 Water @ 10 degC
DT = 10 degC DT = 20 degC Med Grade Steel DT = 16 degC DT = 20 degC Med Grade Steel DT = 20 degC Heavy Grade Steel

Air in = -5 degC Water Inlet = 80 degC Prsre Drop = 200 Pa/m Air in = 21 degC Water Inlet = 80 degC Prsre Drop = 200 Pa/m * Air off temp °C Db/Wb = 21.5/18.5 Water Inlet = 6 degC Prsre Drop = 200 Pa/m
Air off = 5 degC Water Outlet = 60 degC Air off = 5 degC Water Outlet = 60 degC Dh = 10 Water Outlet = 12 degC

Air off temp °C Db/Wb = 12/11.4

Dh = 27.5

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 Pipe Sizing as per Riser Details

AHU PIPE SIZE CALCULATION

Frost Coil Reheat Coil Cooling Coil

Supply Flowrate Mass Flow rate Frost Load LTHW Flowrate Pipe Size Reheat Load LTHW Flowrate Pipe Size Cooling Load CHW Flowrate
AHU m3/s Kg/s KW Kg/s mm KW Kg/s mm KW Kg/s
1 5.986 7.04235294118 72 0.858 40 115 1.372 50 * 70 2.803
2 4.704 5.53411764706 56 0.674 32 90 1.079 40 152 6.058
3 1.336 1.57176470588 16 0.191 20 26 0.306 25 * 16 0.626
4 3.422 4.02588235294 41 0.490 32 66 0.785 40 * 40 1.603
5 2.574 3.02823529412 31 0.369 25 49 0.590 32 83 3.315
6 1.640 1.92941176471 20 0.235 25 31 0.376 32 53 2.112
7 0.750 0.88235294118 9 0.107 20 14 0.172 20 24 0.966
8 1.140 1.34117647059 14 0.163 20 22 0.261 25 37 1.468
9 1.140 1.34117647059 14 0.163 20 22 0.261 25 37 1.468
10 1.140 1.34117647059 14 0.163 20 22 0.261 25 37 1.468
11 0.885 1.04117647059 11 0.127 20 17 0.203 25 29 1.140
12 3.209 3.77529411765 39 0.460 32 62 0.736 32 * 38 1.503
13 1.764 2.07529411765 21 0.253 25 34 0.404 32 * 21 0.826
Sply Flwrte / .85 Q = mc(DT) Q = mc(DT) From CIBSE C Q = mc(DT) Q = mc(DT) From CIBSE C Q = m x (h outside – h offcoil) Q = mc(DT)

Cp (air) = 1.02 Cp (water) = 4.187 Water @ 75 degC Cp (air) = 1.02 Cp (water) = 4.187 Water @ 75 degC Air on temp °C Db/Wb = 28.5/21 Cp (water) = 4.187
DT = 10 degC DT = 20 degC Med Grade Steel DT = 16 degC DT = 20 degC Med Grade Steel DT = 20 degC

Air in = -5 degC Water Inlet = 80 degC Prsre Drop = 200 Pa/m Air in = 21 degC Water Inlet = 80 degC Prsre Drop = 200 Pa/m * Air off temp °C Db/Wb = 21.5/18.5 Water Inlet = 6 degC
Air off = 5 degC Water Outlet = 60 degC Air off = 5 degC Water Outlet = 60 degC Dh = 10 Water Outlet = 12 degC

Air off temp °C Db/Wb = 12/11.4

Dh = 27.5

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 Pipe Sizing as per Riser Details

Pipe Size
mm
65
100
32
50
65
65
40
50
50
50
50
50
40
From CIBSE C

Water @ 10 degC
Heavy Grade Steel

Prsre Drop = 200 Pa/m

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