1. Lecture Objectives: Plumbing Pumps Hydronic distribution systems
Chiller/Boiler – Storage – Building
Pumps
Reading assignment:
Chilled Water Plant Design Guide (Section 4)

2. Primary/Secondary and Tertiary Pumping (schematics A&B below)

3. Coil Pumping Strategies
Variable speed pumps vs. Single pas Valve vs. Mixing valves vs. Diverting Valves

4. Impact of Piping Coil How will this affect needed CHW flow?
What about the chiller performance?

5. Plumbing Arrangement in Building’s Hydronic Systems
Radiators
Baseboard heaters
Fan coil systems

6. What is the difference between these two configuration?

7. Hydronic Terms Head loss Open-loop vs. closed loop Open System
Closed System h
Pump
Chiller
Cooling coil in AHU
Pump

8. Is this open or closed system ?
Cooling towers

9. Relationship between velocity in a pipe and pressure drop
Δp ~ v2
Δp = Constant × v2
Required power (P) for the pump
P = V × Δp P –power [W],
V –volume flow rate [m3/s], v – velocity [m/s]
Δp – pressure drop [Pa]
Δp ~ v2 (Δp ~ V2 – when same pipe is used)
P ~ V × V2 – when same pipe is used
P ~ V P2/P1 = (V2/V1)3 For the same pipe
When different pipe is used for the same flow rate:
For the same
flow rate V
Reduction of D:
smaller pipe
larger pipe
Δp [Pa or ft water] D1
D2= D1/2 A1 V1 P1
A2=1/22 A1
V2=22 V1
P2/P1 = (D1/D2)4 - for the same flow rate
or 50% smaller diameter of the pipe
for the same flow rate wee have:
4 times larger velocity
16 times larger pressure drop and
16 times lager power for the pump
v [m/s or fpm]

10. Head Loss

11. Fittings

12. Pumps Raise pressure and produce flow Main type Centrifugal Example of
Turbine pump
Base mounted
Inline
Reading (textbook)
Page

13. Pump curves
NPSHR = Net Positive Suction Head Required

15. Changing Pump Speed

16. Net Positive Suction Head (cavitation)

17. Curve for Multiple Pumps

18. System Curves ∆p ∆p
A+B A B
A+B A B V A B V A B
Parallel
Serial

19. Find a system curve for this plumbing configuration

20. System balancing AHU1 AHU2 HC1 HC2 100 ft 1000 ft 10 gpm 2 gpm 10 ft
pump
BOILER

21. Valves Section 5-14 and 6-15 in the textbook Types Butterfly Valves
Ball Valves
Globe Valves
Three way valves

22. Valve Sizing and Flow Coefficient
Cv value:
in liter/hour or….
in Pa
Control Valve Selection For Hydronic Systems
reference:

23. Control Valve Selection For Hydronic Systems
Before DC we tried to do this
Valve authority