1. Objectives
Duct Design AND Diffuser Selection

2. DOAS System

3. DOAS with multi-split systems
Fresh air?

4. DOAS fresh air configurations

5. DOAS fresh air configurations

6. Issues Related to DOAS Split of sensible and latent load
Selection of hydronic system
Winter vs. summer operation
Winter operation with DX systems (heat pump)

7. Pressures Static pressure Velocity pressure
Total pressure – sum of the two above

8. Relationship Between Static and Total Pressure

9. Duct Design
Total and static pressure drops are proportional to square of velocity
Plot of pressure drop vs. volumetric flow rate (or velocity) is called system characteristic

10. System Characteristic

11. Electrical Resistance Analogy

12. Frictional Losses

13. Non-circular Ducts
Parallel concept to wetted perimeter

14. Dynamic losses Losses associated with Two methods
Changes in velocity
Obstructions
Bends
Fittings and transitions
Two methods
Equivalent length and loss coefficients

15. Loss Coefficients
ΔPt = CoPv,0

17. Example 18.7
Determine total pressure drop from 0 to 4

18. Conversion Between Methods

19. Air Distribution System Design
Describe room distribution basics
Select diffusers
Supply and return duct sizing

20. Forced driven air flow Diffusers
Grill (side wall)
diffusers
Linear diffusers
Vertical
Horizontal one side

21. Diffusers types Valve diffuser swirl diffusers ceiling diffuser
wall or ceiling
floor

22. Diffusers http://www.titus-hvac.com/techzone/
Perforated ceiling diffuser
Jet nozzle diffuser
Round conical ceiling diffuser
Square conical ceiling diffuser
Wall diffuser unit
Swirl diffuser
Floor diffuser
Auditorium diffuser
Linear slot diffuser
DV diffuser
External louvre
Smoke damper

23. Low mixing Diffusers Displacement ventilation

26. Reading asignement
Chapter 18
(including 18.4)