1. Technology in Architecture
Lecture 15
Waste & Vent Systems
Waste & Vent Sizing Procedure
Bathroom Design

2. Waste & Vent Systems

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

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

5. Vents and Stacks Circuit vents Soil stack Vent stack Stack vent
Note: Drain fittings are 45º
Individual vents
Circuit vents
Soil stack
Vent stack
Stack vent
“Wet stack”
Vent through roof (VTR)
S: p. 1008, F.22.10

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

7. Waste & Vent Sizing Procedure

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

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

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

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

12. 5. Determine loads Fixture location may control size S: p. 1022,

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

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

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

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

17. Bathroom Design

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