Mar 1, 2013 - Building
Libraries For HVAC Applications – Parameterizing instead of programming: ready-made system macros ensure standardization and contribute to cost reductions
Around 40 percent of the energy used in Germany is consumed by buildings. Due to increasing energy costs, energy efficiency in buildings plays an increasingly important role. The DIN EN Standard 15232 defines four energy efficiency classes (A to D), which represent a method for measuring a building’s energy efficiency.
In addition to the design of the main body of the building and the technical systems used, automation technology and the corresponding software exert an enormous influence on energy efficiency.
The fields of heating, ventilation, and air conditioning (HVAC) are of particular interest in relation to energy consumption, as they consume a relatively large proportion of the building’s energy needs. Buildings with a high energy efficiency can be certified according to various standards. Among the most important are the Australian “Green Star,” the German DGNB, the French HQE, BREEAM in Great Britain, as well as LEED and “Green Globes” in the USA.
Planning Lays the Foundation
Planning for the technical equipping of a building forms an important foundation for energy-efficient building operation. One basic requirement is that everyone who participates in the construction shares a common and clear language. Foundations for this can be found in the Construction Tendering and Contract Regulations (VOB), the Association of German Engineers (VDI) 3814, and DIN EN ISO 16484-3. However, nothing is said as yet in the guidelines and standards about the components that are to be used. This applies for equipment as well as for hardware and software for automation.
In technical building services, there exist a multiplicity of protocols and interfaces, via which the individual components can be addressed. In addition to simple analog and digital inputs and outputs, BACnet, MODBUS, LON®, MP-bus, KNX, EnOcean, and DALI are all well represented in the market, as well as numerous others. In larger commercial properties, a mixture made of different protocols and bus systems is often used simultaneously. Therefore, there is a need for automation hardware that can operate all protocols and interfaces in one system, as far as possible. The WAGO-I/O-SYSTEM 750 is the hardware solution to meet this challenge. The controller, which takes on control tasks for the automation solution, can be easily expanded using various system modules, so that almost any devices can be connected to the system.
From Planning to Implementation
The controllers, which use CODESYS Soft PLC, are programmed according to the IEC Standard 61131-3. WAGO has made a comprehensive HVAC library available to their customers in the fields of heating, ventilation, and air conditioning, so that their customers do not have to do the programming themselves. For many common applications, there are suitable system macros, which the user only has to configure. After the user has entered data points and system parameters, the ready-made application can be directly commissioned. Complex programming is thereby avoided, which can lead to significant cost reductions for starting up systems and the re-use of macros simplifies standardized solutions.
Customers can obtain the HVAC system macros free of charge from the company’s homepage. Even complex applications, such as cascade control using cross-flow heat exchangers and frequency regulated fans, are available in the library. Additional function blocks, which allow easy expansion of the available macros, are likewise included in the library.
Initializing the application takes place using a Web-based user interface. The user can set parameters using the interface and carry out any additional configurations of the application. A visualization display is also possible without requiring a large programming expenditure. A Web-server is integrated into the controllers, which graphically depicts the building services, showing the current parameters of the different systems and enabling operation. The only thing that the user has to supply is a standard Web browser. Ideally, WAGO’s operating panels from the PERSPECTO® Series can also be used here.
Bottom Line: System Implementation without Programming
Energy-efficient building automation succeeds only with modern automation systems, which integrate all disciplines within a commercial property, to the greatest extent possible. The HVAC fields play a central role in relation to total energy consumption. Using WAGO’s components and systems for building automation and the appropriate, ready-made applications, which are available at no charge in the HVAC library, the user can implement an energy-efficient building automation system without excessive programming costs. The visual display of the completed building automation is also automatically generated to a substantial extent using the integrated Web server.
- WAGO provides extensive HVAC libraries free of charge
- Pre-made system system macros replace expensive programming through the use of simple parameterization
- Initialization takes place using a Web-based user interface
Text: Karl-Heinz Sanders, WAGO
Photo: © PantherMedia/Fabian Schmidt, WAGO