Technology in Architecture Lecture 14 Upfeed Systems Pipe Sizing Procedure Pipe Sizing Example Lecture 14 Upfeed Systems Pipe Sizing Procedure Pipe Sizing Example

Upfeed Systems

Pressure in Upfeed Systems Fixture pressure head Static head Friction head loss Meter pressure loss M: p. 929, F.21.13

Pressure in Upfeed Systems Proper fixture flow pressureA +Pressure lost due to heightB +Pressure lost due to frictionC +Pressure lost through meterD Total street main pressureE

A: Fixture Flow Pressure Pressure needed to get water through fixture M: p. 987, T.21.14

B: Pressure lost due to height Weight of water column M: p. 929, F.21.13

C: Pressure loss due to friction Initially unknown, must be calculated based on pressure remaining after accounting for the other factors

D: Pressure lost through meter Make initial size assumption and then repeat to optimum size M: p. 988, F.21.63a

E: Total Street Main Pressure Check with water company or fire department

Pipe Sizing Procedure

1. Determine Supply Fixture Units Fixture units take into account usage diversity M: p. 991, T.21.15

2. Calculate Demand Flow Use curve 1 for flush valve dominated system Use curve 2 for flush tank dominated systems M: p. 992, F.21.65a

3. Determine the “Most Critical Fixture (MCF)” Highest and farthest from inlet main Confirm pressure required (A) Identify height (B) M: p. 975, F.21.52

4. Determine Developed Length The total length of all horizontal and vertical pipes from the main to the MCF M: p. 1014, F.22.17

5. Determine Total Effective Length (TEL) Two approaches: 1. equivalent length or 2. multiply DL x 1.5 TEL= DL x 1.5 M: p. 993, T.21.16a

6. Determine Street Main Pressure (E) Contact utility company or fire department

7. Determine Pressure Available for Friction Loss Proper fixture flow pressureA +Pressure lost due to heightB +Pressure lost due to frictionC +Pressure lost through meterD Total street main pressureE or C=E-A-B-D

Meter Loss (D) Since D is unknown, pick an initial size, do calculation, repeat as needed to optimize flow C=E-A-B-D M: p. 988, F.21.63a

8. Determine Friction loss/100’ C=E-A-B-D Δp/100’ = 100 x C/TEL

9. Verify flow for meter size If flow > Total Demand (#2)  repeat 7-9 at smaller diameter If flow < Total Demand (#2)  repeat 7-9 at larger diameter M: p. 989, F.21.64a

10. Select final meter size When flow > Total Demand (#2)  stop M: p. 989, F.21.64a

Pipe Sizing Example

Given Information Small Office Building  public numbers 2 Flush valve toilets 2 Lavatories 2 Drinking fountains 1 Service sink DL: 92’ MCF: Flush Valve Toilet, 16’ above water main Street Main Pressure: 44.1 psi

1. Determine Supply Fixture Units Fixture units take into account usage diversity M: p. 991, T.21.15

1. Determine Supply Fixture Units ColdHotTotal 2 Flush valve toilets Lavatories Drinking fountains Service sink

2. Calculate Demand Flow 20 WSFU out of 27.5 WSFU are flush valves Use curve 1 for flush valve dominated system 40 gpm M: p. 992, F.21.65a

3. Determine the Most Critical Fixture Confirm pressure required (A) 15 psi Height above main (B) 16’  7.0 psi S. p. 987, T.21.14

4. Determine Developed Length Developed length 92’ M: p. 1014, F Note: this figure for generic reference only and does not illustrate the example problem

5. Determine Total Effective Length (TEL) TEL= DL x 1.5 = 92 x 1.5 = 138’

6. Determine Street Main Pressure (E) 44.1 psi

7. Determine Pressure Available for Friction Loss Proper fixture flow pressureA15.0 +Pressure lost due to heightB7.0 +Pressure lost due to frictionC? +Pressure lost through meterD? Total street main pressureE44.1

Meter Loss (D) Pick an initial size 2” diameter… 1.4 psi M: p. 988, F.21.63a

8. Determine Friction loss/100’ C=E-A-B-D = = 20.7 psi Δp/100’=100 x 20.7/138 = 15 psi/100’

9. Verify flow for meter size At 2” Flow=150 gpm > Total Demand 40 gpm At 1-1/2” Flow=60 gpm > Total Demand 40 gpm (Δp/100’= 13.1) At 1” Flow=13 gpm < Total Demand 40 gpm (Δp/100’= 5.1) M: p. 989 F.21.64a

9. Verify flow for meter size When flow > Total Demand (#2)  stop At 1-1/2” Flow=60 gpm > Total Demand 40 gpm (Δp/100’= 13.1) M: p. 989 F.21.64a

Pipe Sizing Use Δp/100’= 13.1 psi/100’ Use fixture units to determine flow M: p. 989 F.21.64a

Pipe Sizing Use fixture units to determine flow Pay attention to flush valve domination M: p. 992 F.21.65a

Pipe Sizing Use Δp/100’= 13.1 psi/100’ Use fixture units to determine flow Select size which does not exceed 13.1 psi/100’ 20 gpm, use 1” 10 gpm, use ¾” Use runout sizes at each fixture M: p. 989, F.21.64a

Runout Pipe Sizing Use actual flow to size runouts Lavatory:2 gpm M: p.987, T.21.14

Runout Pipe Sizing Use Δp/100’= 13.1 psi/100’ Lavatory: 2 gpm M: p. 989, F.21.64a

Notation System Suggested for organizing data WSFUCurve Flow Diam. M: p. 1014, F ¾” ½”

Waste & Vent Systems

Fundamentals Siphon action can drain water Trap blocks sewer gas Vent breaks siphon M: p. 1006, F.22.8

Air Gaps Eliminate the potential for cross contamination M: p. 1009, F.22.11

Bathroom Design Considerations ADA compliance ANSI Standard A Wheel chair access Grab bars Counter top/fixture heights Visual privacy Acoustical privacy

Vents and Stacks Individual vents Circuit vents Soil stack Vent stack Stack vent “Wet stack” Vent through roof (VTR) M: p. 1008, F Note: Drain fittings are 45º

Drains & Sewers House drain House sewer Storm drain Clean outs House traps Fresh air inlet M: p. 1007, F.22.9 Note: Drain fittings are 45º

Waste & Vent Sizing Procedure

1. Identify waste & soil locations Clusters are more efficient M: p. 1014, F.22.17

2. Layout system vertically & horizontally 2. Layout system vertically & horizontally Grouped fixtures can be stacked in a vertical riser M: p. 1027, F.22.31

3. Size Traps Trap size is used when connecting to main M: p. 1017, T.22.2

4. Calculate Drainage Fixture Units (DFU) Pipe sizes based on DFU M: p. 1017, T

5. Determine loads Fixture location may control size M: p. 1022, F.22.24

6. Determine slope and size of horizontal drains 6. Determine slope and size of horizontal drains Slope may be constrained by depth of floor cavity M: p. 1020, T.22.5

7. Verify maximum vent length Measured from plans M: p. 1022, F.22.24

8. Size vents according to DFU and length Calculate for each vent load and developed length M: p. 1019, T.22.4

9. Verify space requirements and adjust design Common adjustments “Wet” walls  6” cavity Slope and ceiling exposure Cleanout access