Variable Volume Chilled Water Pumping System Control

Variable Volume Chilled Water Pumping System Controls
Dave Hacker – Engineering Manager Kyle Schroeder, PE – Sales Engineer

Outline
• Introduction • Chilled Water Pumping Systems Configurations / Control Strategies
– Primary – Secondary Pumping – Variable Primary Pumping

• Demonstration / Live Web Graphics • Discussion and Questions

Local Service and Support Innovative Energy Solutions
• 45 year record of successful project installations
– Hundreds of local DDC installations

• On-staff engineers, technicians
– Factory-trained

• 24 hour 7 day on-call service for Temperature Controls and Full HVAC Mechanical Service • Service agreements • Comprehensive local parts stock • Local training • Over 250 years HVAC / Controls experience on staff

Evolution of Pumping Systems

y log hno Tec e Curv
Constant Speed Systems

VFDs
1990s

hiller ow C le Fl ariab V
2000s

Pump

1980s

In n ova Primar y / Sec tion on

3-wa y val ves

ndary Bypa ss V alves

Basic Chilled Water Pumping System

Basic Chilled Water Pumping System
• Single Chiller, Single Constant Speed Pump • 3-way valves for all Chilled Water Coils ( ) maintains constant flow. • Control strategy: Enable chilled water pump when outside air temperature is above setpoint and at least 1 chilled water coil control valve is open to coil. Enable chiller after flow is proven. Chiller operates to maintain leaving chilled water temperature at setpoint. Coil valves modulate to maintain comfortable space conditions. or even more basic – no valves – full flow

Basic Primary / Secondary Chilled Water Pumping System with a 3-way valve

Basic Primary / Secondary Chilled Water Pumping System
• • • • Single Chiller, Single Constant Speed Primary Pump, bypass loop with no valve, Variable Speed Secondary Pump. The primary pump pumps water through the chiller. The secondary pump pulls water from the primary system and pumps it to the coils. Add a Water Differential Pressure