See Chapter 1, The Six Steps of HVAC DDC Design, for details.
See Chapter 5, DDC System Architecture, for details.
BACnet is an industry standard communication protocol for Building Automation and Control Networks system designed by the American Society of Heating Refrigerating and Air Conditioning Engineers (ASHRAE). BACnet infrastructure is modeled after the Open Systems Interconnections (OSI) 7-layers described in Chapter 5, Building Automation, LEED, and Commissioning. The difference is that BACnet infrastructure uses only layers 1, 2, 3, and 7 of the OSI layers. Table 5-2 graphically illustrates this infrastructure. See Chapter 6, ASHRAE BACnet, for details.
Native BACnet is a terminology adopted by BACnet manufacturers. It refers to those DDC systems for which every component is BACnet compatible at the device level. Theoretically, two native BACnet devices by two different manufacturers can communicate on the same bus with minimal interface preparation. See Chapter 6, ASHRAE BACnet, for details.
LonWorks is a family of hardware and software products developed by the Echelon Corporation. Figures 6-1 and 6-2 in the book compare the traditional method and the Lon approach for networking of various smart systems within a facility. The LonTalk networking protocol is based upon the OSI 7-layer model as described in Chapter 5, DDC System Architecture. See Chapter 7, Open Systems and LonWorks Platform, for details.
See Chapter 7, Open Systems and LonWorks Platform, for details.
SNVT stands for Standard Network Variable Type and is pronounced “snivet.” See Chapter 7, Open Systems and LonWorks Platform, for details.
LonMark is a brand name and an association. The LonMark Association was formed in 1994. Its purpose is to promote and support those manufacturers that produce interoperable LonWorks products. The LonWorks devices that have been certified by the LonMark Association carry the LonMark logo. See Chapter 7, Open Systems and LonWorks Platform, for details.
PLC stands for Programmable Logic Controllers. See Chapter 2, DDC Controllers, for details.
The five most commonly utilized HVAC control systems are: 1) Pneumatic Controls, 2) Electric Controls, 3) Self-Powered Controls, 4) Electronic Controls, and 5) Direct Digital Controls. See Chapter 3, Basics of HVAC Control, for details.
A gateway is intelligent translator hardware that allows two incompatible DDC networks to connect and communicate. A bridge is intelligent hardware that connects two compatible or identical networks. See Chapter 2, DDC Controllers.
Routers are intelligent hardware that filter the passing of messages between two network segments. They only allow messages that need to get from one bus to the other through the router. A repeater is hardware that connects two identical networks. See Chapter 2, DDC Controllers.
A smart sensor contains a certain level of "intelligence" and some form of controller capability that may allow for transmission of digital signal directly to the network. See Chapter 2, DDC Controllers.
Smart actuators contain intelligence and some form of controller capability. This allows for an actuator to receive and analyze an algorithm from the network, a sensor, or another device. See Chapter 2, DDC Controllers.
Application Specific Controllers (ASC) refers to a family of DDC controllers, each designed to perform one specific function for one specific scenario. Manufacturers generally mass-produce application specific controllers for the most common applications. This reduces the production cost as well as installation cost since most application specific controllers are pre-programmed and require only minimal adjustments in the field. See Chapter 2, DDC Controllers, for a list of some of the most commonly used application specific controllers. Also see Figures 2-3 and 2-4.
Ethernet is both the data link and physical layer. It operates at a high speed of 10 to 1000 Mbps. It operates based upon carrier sense multiple access with collision detection (CSMA/CD), and is highly efficient until the system becomes heavily loaded. Therefore, Ethernet is an indeterminist system. Refer to Chapter 5 for details.
ARCNET is both data link and physical layer. It operates at a speed of 2.5 Mbps. It operates based upon a peer-to-peer token passing bus; thus it is deterministic. ARCNET implementation is typically less expensive than Ethernet. Refer to Chapter 5 for details.
Pneumatic control is a type of controls system that utilizes low pressure compressed as a source of energy to sense and control devices. See Chapter 9, Pneumatic Control and DDC.
There are three types of control valves used most often in HVAC systems (globe valves, ball valves, and butterfly valves). See Chapter 11, Control Valves, for details and selection of modulating control valves. Review the four major considerations in this chapter and learn how to size control valves.
The five types of electronic temperature sensors most often used are resistance temperature detectors, thermistors, thermocouples, silicon transmitters and integrated circuits, and infrared sensors. Refer to Table 13-1 for applications, advantages, and disadvantages. Also see Chapter 13, Electronic Sensors, for details.
There are a large number of humidity sensors on the market, many of which are made by very reputable companies. The two types that are most commonly used and discussed in the book are relative humidity sensors and dew point sensors. There are two types of polymer relative humidity sensors. See Chapter 13, Electronic Sensors, and refer to Table 13-2 for comparison and details.
Yes. The following is a list of flow meters discussed in this book: Turbine (Inline Turbine, Insertion Turbine); Differential Pressure (Orifice, Venturi, Pitot Tube); Vortex (Vortex Shedding); Ultrasonic (Doppler, Transit time); Electromagnetic; and Special (Positive Displacement). See Chapter 13, Electronic Sensors, and refer to Table 13-3 for comparison and details.
See Chapter 13, Electronic Sensors.
See Chapter 13, Electronic Sensors.
See Section E: Practical Scenarios for details. This includes the following chapters: Chapter 14, Practical Examples of Chilled Water System Control; Chapter 15, Practical Examples of Condenser Water Control Systems; Chapter 16, Practical Examples of Hot Water Systems Control; and Chapter 17, Practical Examples of Air Handling Unit Control.