PRESENTATIONS

Energy-efficient in ELCON way or energy-conscious way of thinking and operating, 2010.06.20
ELCON ENERGY MANAGEMENT PYRAMID
If you are interested in various energy-saving options, please read our presentation.

Building monitoring system for economical operation
The general architecture is the three-dimensional environment created by man, and usually defined and delimited by and artificial space. The quality of architectural design method is strongly dependent on the society’s actual intellectual and economic conditions, possibilities. So the changes in the society can be quickly found in the field of architecture.

Building monitoring system foreconomical operation
The general architecture is the three-dimensional environment created by man, and usually defined and delimited by and artificial space. The quality of architectural design method is strongly dependent on the society’s actual intellectual and economic conditions, possibilities. So the changes in the society can be quickly found in the field of architecture. Hungary in past short period of construction industry has undergone a huge development. Modern world class shopping centers, office buildings, apartment houses grew out of the ground one after another. These establishments have higher standards in all areas comparing to previous ones. The higher requirements are both quantitative and qualitative level improvements. Over the time the number of investments resulted in a very competitive field to win lease contracts. For the competitive rent prices, it was crucial to reduce operating costs to the optimal level. It became important for operation to be high quality, and efficient, but the cheapest as possible. The operation of such buildings was no longer possible with the old methods. Then the facility management expression entered the Hungarian public awareness.
The FM’s task is the high-quality and economical operation of the object. But, if you look closely what are hidden behind the previous short sentence, you realize that this could be a separate topic of the presentation. The FM includes real estate services in short and long-term planning, and it develops and ensures legal, financial and technical background. Nothing new in this field indicates the importance better than the domestic technical, economic higher educations institutions launched a series of courses in the area. Today the profession has an international organization, which is called the IFMA (International Facility Management Association).
The tasks related to the operation can be seen on the figure 1 (click to zoom), and it is divided into four groups. It can be seen that in certain areas the processes strongly interact with each other. It follows that today the safe and efficient operation of the building or building systems is unimaginable without modern IT system. These computer networks and data management possibilities are used by the connected object operating modem, safety, fire, and building control and regulatory systems.
Since the building operation tasks usually not adapted to the subsystems, therefore it is necessary to exchange data between the subsystems, and to coordinate the operation. Today various software systems are available for long-term date recording, and fast selectable evaluation. The building with such background information is called intelligent buildings. The characteristics of intelligent building are the much more information collection and storage from our environment, and even from external sources than conventional buildings. The software can also forecast through a high-level, multi-elemental examination process. This makes all the building operation tasks handled easily. Let’s take a further look at how building management system is made up, and how it contributes to the efficient operation of and intelligent building.
Building Management Systems
System knowledge and components
The building management system’s task is the automatic operation of mechanical and electrical equipment in a building, and to visualize and record the operation parameters on the central computer display. Such a system architecture diagram is shown in the second figure.
The modular components allow building a flexible structure network. The program, running on digital control devices in the network, operates the technological environment independently. It is able to receive data, on serial communication line, from other participants in the network. This allows synchronizing the operational procedures with other farther systems. The pre-set parameters, or the program loaded in the device can be modified with commands coming from higher level on the communication line. We can send messages or transfer data to different points in the network about any system state or value change. The operation of the devices can be achieved by centralized or divided intelligence.
From the monitoring system’s point of view the connected devices can be divided into two basic groups. The first group includes the various actuators, sensors, thermostats, pressure switches and other voltage free contacts operated peripherals. These digital control devices connected directly to the in- and outputs. Since these devices do not have their own intelligence, therefore the operation is fully performed by the connected digital device.
The second group includes devices, like measuring instruments, which has a microprocessor built in by the manufacturer. These might include for example meters, pumps, coolers and boilers. These units have their own communication tools. Two different types of intelligent systems can be connected by a various number of international standard approved ways. These standards define the physical parameters of the communication lines and transmission method. In case of two different systems, an interface must be provided to convert the data from one protocol to another, and vice versa. So the various systems appear in their own point of view as if they were the same. The device, which performs the mentioned functions is called protocol converter. However in order that the extracted data from on system to another can be used and viewed, we must know the data structures. This determines how the incoming data should be applicable on the data communication lines (e.g., water temperature, operating status, error). The data structure varies by the type of device usually must be obtained from the manufacturer.
 In case of a larger object the number of connected peripherals can be thousands. Their operating, monitoring result in significant on the communication network. Since only a part of the network needs the set of data, so in case of larger networks it is advisable to establish sub networks. These so-called sub networks connecting to higher level of networks with a router. The routers decide if the set of data would make the higher level of networks busy.
The highest level of building monitoring network is the building management server. Programs running here are continuously checking if networks, sub networks, and devices are working properly, with minute-book record. The system operating procedures of descriptive data, messages, and the automatic and direct process intervention are recorded here. The standard database can be easily accessed from a remote computer’s monitoring and analyzing software. It is also possible to send text or voicemail messages to the predefined phones in case of abnormal operation.
Building monitoring system planning
It can be told if the building will meet the modern requirement during the planning stage. The success of long-term operation is depending on the investor, planner, contractor, and operator and their common work. It is therefore important to deal with those problems up to a few sentences, which are currently a major, a negative impact on the quality of investment.
In most cases the operator can only be selected around the end of the construction. This means that the operator needs usually do not appear in the plans, or just partly. The competition between the constructors leads to the reduction of technical content of the planes system, which result in the system reserves reduction, sometimes to zero. It is frequent that the change in the technical content does not appear in the plans because of the trust in the construction company’s knowledge. This means that the constructors only realize the change of mechanical performance due to a surplus of electric power only in the final stage, and the increasing effects of space is not even mentioned. It is always hard to find a solution for the problems in the final stage because of the time limit, and the extra costs. Then we come back to the importance of good plans. It is important that the plans are well prepared, not because it is necessary to transfer the documentation, but in order to meet the objectives of future construction and operation.
In the process of planning we have to ensure the possibility of negotiations between the different specialist designers. We have to make sure about appearance of the changes effecting other areas. More than half of the cases did not have a higher proportion of incomplete or non-thought description of the operation of mechanical systems. This can lead to the automation designer and contractors start to improvise. In the field wiring a significant attitudinal change has taken place. Recent fire events also put focus on this area. More and more places require halogen-free, flame-retardant cables and stands. Care should be taken that the electrical cord and control plans to be included in this list. Otherwise, significant replacement cost should be calculated, because fire-resistant cable cost twice of sometimes more than the regular cables. During takeover plans should reflect the current status, since all the later conversion, enlargement will have the plans as starting point.
Building monitoring system construction
In the following we review the major phases of construction of monitoring systems and rules that should be taken into consideration, because it can cause mistakes. The first step of the process is to install the peripherals. It is essential to install the devices according to the installation manual. The devices should be pointing the right way, to confirm the flow direction. For outdoor installation, only devices, which were designed for outdoor can be used, otherwise their protection have to ensured. It is important to know that it is not just water protection but it also means protection against temperature. The actuator should be positioned so that the dripping condensation water does not destroy them. The most common problem is usually the frost protection. In many cases they don’t think about it, or it is not carefully installed. It is essential that the frost sensor device is places where the frost can occur. This means that, for example, the air-handling heat exchanger’s total cross section should be observed, therefore the thermostat capillary tube should be placed evenly. The sensors should be installed on points, where fair value can be measured. The immersion of the fluid and duct sensors has to be ensured. The hall sensors should be place where strong flow of air and radiant heat cannot affect the result. The peripherals, which are not properly installed, will lead to incorrect operation of control loops. These errors appear during setup, adjustment, because some peripherals were hidden (ceiling, insulation). The repairs can be carried out at additional cost. To avoid this, the listed above should be taken into consideration.
The power and control cabinets perhaps the most important parts of the monitoring system.The high and low voltage parts can be built into the switchboard, or located separately. This occurs when other electrical company does the power machinery work. It is usually cheaper if you use a common switchboard. It is a frequently occurring problem that the switchboard’s position is in constant consultation. The mechanical elements for various reasons do not fit the intended area and therefore the designated route overruns on the pipes. In better case it only prevent the door to open, but the worst is when it makes impossible for it’s installation. The high voltage power distributors installation is dangerous, so in order to avoid the accident, we have to make sure there is enough space for installation. In addition, the switchboard indicators, switches, labels should be positioned so that they can be handled and overviewed quickly and easily. Care should be taken if the regulators are place outdoors, then the ventilation in the summer, and the heating in winter should be provided. All has to meet the moisture protection requirements. Availability should be made for smaller system expansions, conversions. This requires 10% spare space. A copy of progress plan should be place into the switchboard for recording conversions, extensions during operation.
During wiring it must be ensured that the marks on the cable will be seen even after connecting into the switchboard. The sizes of cable structures must be chosen so that the cables will be able to be placed aesthetically. For hard to reach, muffled places it is advisable to wire an extra cable for additional expansion. Before connection the supplied electrical equipment should be checked if they match the plans. We have to take care about the engine types, and the operating voltage and protection. Once all the connections in the field and both sides of the switchboard are done, check the engine protections, rotation directions and the physical existence of the DDC devices input signals. It is important for the test to remove a short locks (fire protection), and the removed devices should be reconnected, to avoid significant damage may occur. Make sure that the field in this connection is still prohibitive. Do not forget to check the shock protection system.
Before loading the program, let’s look if the controlled signals appear on the physical side of the peripherals and on the software channel as well. Examine the existence of the communication connection between the DDC devices and the center. Then the user can load the software and set up the automated system. During the adjustment we can set up the operating parameters, and eliminate the control system’s sway. It is important to know that the setup of automatic control loops should only begin on systems where the air and water adjustment is already carried out. If the work points of the mechanical system are not set properly, we cannot provide stable control with the DDC devices.
According to the original system, the slippages should be continuously recorded in the plans, so at handover the documents will reflect the accurate truth. The handover documentation should include progress plan, list of user software, devices data sheets, certificates of the manufacturers, constructor declarations, shock protocol, official license, guarantee statements, and the minute-book of the operator education.
Building operation
Operational strategy setup
Operating larger building from central location, as previously read, requires a lot of information. The information, which cannot be obtained from the central computer, needs human resources. For example, if the temperature is not valid somewhere, but the reason cannot be read from the screen, someone has to go there and check what happened. The same situation happens in case the lighting system is not connected to the monitoring system. Then the operators can operate the lights, so the level of building monitoring system in an area is related to number of operators.
Today’s buildings are so varied and complex, operated by high-value equipment that they require considerable expertise. Since the maintenance activity is not a continuous, it is very expensive to carry out permanent work force for it. We need to define the routine like tasks, and does not require a high level of expertise. These should be carried out by own employees. For remaining maintenance process contract should be made.
Building overtake for operation
Today’s practice is that the operators go through training as a part of the handover process. Then couple of hours is usually available for the operators to get used to the building’s mechanical and electrical system. We need to keep in mind that DDC number of data points is around 1000, so it is needed to see this efficiency is very low. The operating staff should take over and know the handover documentation shown in section 2.3. Symbols shown in the plans should be identified with the installed equipment, and shall be capable of basic level troubleshooting. It is advised to generate artificial failures, and to solve it the problem together. Trainings should be frequent for old and new members of the staff.
Maintenance
We often find that after the handover the operator, because of budget cut, does not contract for maintenance because the system is under warranty anyway. However, this is mistake, which often forgets the short-term savings. The dust, water, corrosion and other contaminants do not distinguish between warranty and non-warranty equipment. The lack of maintenance reduces the life expectancy of high-value equipment. On automation system at least 2 maintenance is need a year. It should be done before cooling and heating season.  For larger systems two intervening control is recommended.
Use of operator experience
The operator’s task is to synchronize the building management system with the building operation. This means to write the time program into the control system, and to ensure the requested temperature for the specific areas, and to set the minimal required operation for the unused areas. Attention should be paid to the building’s different performance and consumption data, to recommend a more efficient operation procedure. In case of large consumers reducing simultaneous operation, and changing the desired temperature values.
Building operation in practice
The Sugar shopping center’s building automation system examination
Based on the above, I can demonstrate the benefits of constructed and operated building monitoring system through a practical example. To do this, I chose Sugar shopping center, because we can examine a building probably known by everybody, and the machinery has operated for more than ten year with analog controllers, when the new building management system with digital controllers has been built. Since then nearly a decade passed, so we can take longer time under data examination.
The building opened its doors in November 1980, which became Hungary’s first shopping mall. The project lasted for several years, which at that time was completely normal. The building was designed in 1971 but the constructions only begin in 1976. It had much bigger base then the other shopping centers at that time, and the internal structure was completely different too. The total area was 28818 square meters, and the biggest part of that (18,665m2, 65%) were the commercial and service units. The total built-in volume was 149,073 m3. This space had to be served by the building’s mechanical system. The building received heat on distance pipelines, from two heating stations. One on the east and the other was on the west side. The heat distribution was the following:
* Heating: 1080kW/hour
* Hot water: 350kW/hour
* Ventilation: 3220kW/hour
* Total: 4650kW/hour
The number of people in the building heavily influenced the amount of energy consumed.
The building plans included also cooling system, which was carried out. This was unusual at the time. Air-conditioning equipment was only used in few places. Two liquid coolers were installed, with the performance of 2.35 MW. The system produced 6 ? C water for air handling and fan-coil equipment.
To ensure the proper operation of the building, the designers realized the need to establish a control center. In the center the loudspeaker management, security and fire protection functions, and limited system monitoring and controlling took place.
Since it was an analog system, wires were laid between the devices and the center, but they did not pay enough attention to shield during laying, so the modern measuring instruments places in multi-shaded box was unable to send correct but sometime not even near values. Analog signals on long cables interfered with other signals, so the signals to the meter were almost independent from the initial signals. They tried a few different methods to eliminate the distractors, but it never succeeded. The control center’s main task was the monitoring. Since the display devices were provided from the west import, designers planned only the most necessary items. This was not an advantage. The sensors sent analog signals on shielded cables to the control center, where different display indicated the values. The continuous values could be read on screens, although it could not indicate the approximate value. The two level signals were indicated on small lamps by the system. This system had a disadvantage that in case the bulb didn’t light, they could not decide whether the bulb is gone or the signal stopped. While the operators did not have enough experience, this was a serious problem. Sometimes the water leaking spread on stocks, but they couldn’t realize the problem in time because of the malfunctioning displays. This problem was solved the changing the bulbs and indicators weekly/monthly, and employing more people, whose task was to check each value on the display and match it on the value on the area. System became safe but highly questionable.
The dispatcher’s duties included the evaluation of the data on the display and take the decision on his own experience. He gave the instruction to the maintainers to manually set the switches and valves on the desired location. From this perspective the system was considered semi-automatic. According to the operators’ notice, when a new employee arrived, but didn’t have enough experience, they couldn’t keep the operation optimal because of the lack of precise instructions. In those periods the temperature fluctuations and energy consumption has grown noticeably.
The reasons mentioned lead to upgrading and replacement of the system in the shopping center in 1989. Since it was pointless to upgrade the old analog system, the operators decided to change to whole system, and set up a completely new building automation system.
In 1994, the control center has undergone significant transformation. The large front panel were placed put of service and dismantled. It was replaced by a more reliable, 24-hour operating personal computer, which runs graphical monitoring program, so it is easy to track system values, and stated in real time. In case of any problem, the central computer alarms, and draws attention to possible problems that can be automatically eliminated, which requires human intervention. Obviously, the system is much more reliable, and able to keep the building in the most optimal state. All this can be carried out without any human intervention. It needs only one person to sit in the control center to see if an error report appears.
When the building was designed, it was generally accepted that the building was heated by district heat. District heating has many pros and cons; therefore, it is hard for the owners to decide in case of a new building. In Hungary district heat is unpreferred, because it is too expensive. However, many factors influence the price.
In Hungary, the price of gas is kept artificially low by the present day, so the district heating has handicap compared to gas heating. However, this difference will be expected to decline, because in the EU the gas price is much higher and the domestic price should be adjusted to that. Moreover, the relative price of district heat has more administrative costs that the gas, which also must be paid. Another disadvantage of the district heat is that the consumer has no influence on the provided water temperature.
District heat has more advantages. Perhaps the most important thing is that it is an environmental friendly energy. The district heat is produced in centers with high-performance, high-efficiency boiler to heat up water, so it makes it even economical. If these centers located next to power plants or incinerators, they can use their waste heat. The second important aspect is perhaps the simplicity, which was a decisive factor in case of Sugar shopping center. There is no need to built complicated and expensive boilers. The incoming pipelines of district heat, does not require sophisticated equipment, which can save space and cost as well.
These were most of the reasons why they did not replace district heat to boilers in the shopping center during renovation. Incidentally, it is easier now for the heating energy consumption analysis, because the same heating system was used before and after the building automation was in use. The energy used is shown in the following figure. (Figure 3.)