DDC Controls

DDC system components, terminology and design options have created many challenges for engineers and facility operators. Open protocols have also increased customer expectations, but have added complexity to the planning and design process. If you plan, design or specify DDC systems, you will receive a comprehensive understanding of current technologies and options.

Master direct digital control systems by learning how to:

• Define your DDC requirements to control HVAC and related building systems
• Identify the hardware and software elements that make up a DDC system
• Evaluate the advantages and/or drawbacks of open systems (BACnet)
• Plan for IT and cybersecurity concerns
• Avoid common problems when controlling air handling units, VAV systems, central plants, and more

• Consulting, design, and energy engineers
• Building owners, facility managers, and operating staff
• Commissioning authorities
• Contractors and building HVAC control service organizations
• Technicians responsible for the design, acquisition or operation of environmental control systems in commercial, institutional, or industrial facilities

Click here to learn more about the course instructors.

Examine the capabilities of DDC systems and learn:

• The importance of having a planned system architecture
• If open protocols add value with respect to your requirements
• Control strategies for a variety of HVAC system types

This course will give you a broad range of knowledge to understand the principles and technical concepts used by various manufacturers. This understanding is essential to acquire, implement, and operate a cost-effective system. While various manufacturers are discussed during the course, the course content is not specific to any vendor.

A laptop computer or tablet is required for the course.

Download the full agenda in PDF format here

MONDAY (8 AM to 5 PM)

Course Overview

Introduction to DDC Systems

• Basic elements of control
• Feedback concepts
• Loop response
• Terminology
• Types of hardware, software, and firmware

Introduction to the Controlled Systems: Part 1, Load Dynamics 

The Nature of the Problem

• Developing a Simple Control Loop

Supplemental Content: Introduction to the Controlled Systems: Part 2**

• Pumps and Fans
• Ducts and Pipes
• Heat Exchangers
• Refrigeration Cycles and Cooling Equipment
• Boilers and Heating Equipment

Input and Output Data Flow

• AI, DI, and PI
• Analog to digital conversion
• Sensor types, applications, accuracy, stability, calibration, and other factors
• Safeties, limit devices, and power monitoring
• AO, DO, and PWM
• Digital to analog conversion
• Transducers; damper and valve actuators
• Configuring network data flow
• Important performance factors

TUESDAY (8 AM to 5 PM)

Inputs and Outputs: The Field Perspective

• Where We Came From
• Averaging Sensors, Thermal Lags, Position Effect Proxies
• Calibration Offset vs. Multi-Point
• Actuators
• Code Issues and Terminal Strips

Supplemental Content: Pneumatic Controls**

System Architecture

• Network concepts
• Generic components
• Communication concepts
• Local vs. global information
• Installation issues

IT Considerations

Open Systems – the Myths and Realities

• Do you want an open system?
• Understanding IT vs. DDC
• Cautions and concerns
• Different levels of open systems
• Engineering issues

Cybersecurity

WEDNESDAY (8 AM to 5 PM)

System Architecture for BACnet

Supplemental Content: Network Architecture, from the Field Perspective**

Programming Tools

• Types of programming
• Logic diagrams and programming symbols
• Designing control logic

Controlling Analog Processes 

• PID Control
• Open Loop vs. Close Loop Tuning
• Lags and the Two Thirds Rule
• Supplemental Content: Controlling Analog Processes – Lags**
• Supplemental Content: Controlling Analog Processes – The Impact of Lags, an Example**
• Supplemental Content: Controlling Analog Processes – Guidelines for Tuning Loops and Functional Testing**

Application Requirements: The System Concept

• Organizing your information
• Process by process approach
• Supervisory logic
• Working with System Diagrams

Controlling the Mixed Air Section 

• Strategies and control logic
• Assessing an Economizer in the Field
• Supplemental Content: Mixing Air**
• Supplemental Content: Limiting Economizer Operation**
• Supplemental Content: Assessing an Economizer**

THURSDAY (8 AM to 5 PM)

Controlling the Air Handling Unit Section

• Heating, cooling, humidification, and reheat

Controlling the Fan

Controlling Constant Volume Systems 

Central Plants: Pump Interactions and Affinity Laws

• Controlling a Condenser Water System
• Supplemental Content: Controlling Different Central Plant Technologies**

 VAV Systems

• Terminal Unit Basics
• Supply and Return Fan Flow
• Loads and Coil Discharge Temperatures
• Minimum and Maximum Flow Settings
• Supplemental Content: Flow and Pressure Measurement**

FRIDAY (8 AM to 12 Noon)

Defining, Planning, Procuring DDC Systems

• Architecture; Types of Hardware
• Integration and/or Interoperability Concerns
• Operator Interfaces; Training
• Acquisition Strategies; Sole-Source vs. Multi-Vendor
• Open Protocols
• Key to Success

Specifying Your System

• System Descriptions
• Materials; Devices; Hardware & Software
• System Setup
• Specifying Commissioning of DDC

DDC System Commissioning 

• Documentation Review
• Start-up Checks
• Functional Performance Tests (FPT)
• The Five Principles of DDC

**Supplemental Content is included in course materials, but may or may not be presented during class based on time and attendee questions/requests.

Steve Briggs

Steve has been an Electrical Engineer with Facility Dynamics Engineering for 20 years. He formerly worked at the Construction Engineering Research Laboratory (CERL) campus of the Engineer Research and Development Center (ERDC) in Champaign, IL.

For the past 15 years, Steve has worked with the Army Corps of Engineers on the development of DoD Unified Facilities Guide Specifications (UFGS) and Unified Facility Criteria (UFC) for Open Building Automation Systems based on BACnet, LonWorks, and the Niagara Framework. In the past, he has also authored similar Lon and BACnet-based guide specifications for Region 9 (West coast) of GSA.

J Santos

Jay Santos, PE, president, Facility Dynamics Engineering, Columbia, Maryland, is a consulting engineer with more than 25 years of experience in HVAC system troubleshooting, modernization, and automation, he has served commercial, institutional, and industrial clients worldwide. He is a highly respected educator, having supported the HVAC continuing education programs of several major universities.

David Sellers

David Sellers, senior engineer, Facility Dynamics Engineering, Portland, Oregon, has more than 30 years of experience with commissioning, design engineering, facilities engineering, mechanical and control system contracting, and project engineering. His work spans a wide array of facilities, ranging from hospitals and semiconductor clean rooms to commercial office buildings and research/pilot projects in the energy efficiency and sustainability arena.