Building Management System (BMS): Functions And Benefits

MVAC Functions that can be Managed by BMS

Discuss about the Development of intelligence analytic model.

BMS can be used to manage different functions in a building. Figure 1 below shows general functions that can be managed by a BMS system.

Figure 1: Functions that can be managed by BMS

Below are explanations of building functions that can be managed by BMS:

BMS can be used to monitor, control and optimize performance of all MVAC components to ensure circulation of good air quality and thermal comfort in the building (Wong & Li, 2009). It can measure building conditions, including air flow rate, humidity and temperature, then activate the relevant MVAC components to bring indoor air quality and thermal comfort to the desired level (Greener Live Performances, (n.d.)). For the university’s academic building, the following MVAC functions can be managed by BMS: chiller plant and its associated components, library floors’ air system, ventilation in various spaces including car park and public corridors, thermostat control, fun coil units in various areas such as classrooms, public corridors laboratories and open space, primary air unit, temperature profile and data logging.    

BMS can use occupancy sensors to control operation of luminaries by switching lights on/off (AutomatedBuildings.com, 2010); control light dimming based on daylight intensity; switch specific lights, such as external security lights, on/off based on their duty schedule (Modern Building Services, 2016); and maintain logged data and energy consumption history of all lighting fixtures. This helps in reducing energy consumption and wastage (Dilouie, 2009).

BMS can be used to automatically control, monitor and optimize energy consumption and performance of all electrical appliances (Wang, 2010), including: desktop computers, laptops, scanners, projectors, printers, photocopiers, dishwashers, televisions, coffee makers, etc. The system can keep records of voltage, current and power factor of all appliances in the building. This helps in identifying maintenance needs and reducing energy wastage and usage through automation (Makarechi & Kangari, 2011).

BMS can be used to monitor and control operation and conditions of various plumbing system components, such as pump, solar heating system, water fixtures, etc. It can also be used to initiate activities such as hygiene toile flushing, thermal disinfections and circulation of fresh air in washrooms on a regular basis.

BMS can use security components such as motion detectors and CCTV cameras to monitor motions inside and around the building. It can keep records of door access contacts, watchman tours and any burglar attempts. The BMS system can be designed to activate security or burglar alarms if there is any detection of security breach.  

BMS system can be used to restrict building access by requiring login credentials before a person can be allowed or denied access into different areas or rooms within the building. Using its built-in security features, BMS can ensure that doors open only when the login credentials are correct or else they remain closed thus denying entry or exit.  

BMS can be used to monitor presence of fire, smoke or any toxic gases in the building and activate the respective alarm system depending on the amount of toxic gas or intensity of fire. It does so using smoke detectors, heat detectors or fire detectors.

Lighting Control using BMS

BMS can control operation of lifts and escalators depending on their duty schedule and presence/absence of occupants. It can control speed of operation depending on the floors the passengers are going to. During non-peak hours, the system ensures homing of lifts to ground floor and switches of ventilation fans and lighting.

In general, BMS is used to manage building functions that consume energy and water. The BMS system ensures that these functions operate within their design parameters and user requirements, consume minimal energy or water and are maintained appropriately to avoid damage or overconsumption of energy or water (Gao, et al., 2014).

BMS system and components can perform a variety of functions. Some of these include:

BMS system can created duty schedules for different components in the building. This implies that the components will only operate during their duty cycle. At the start of duty cycle, BMS system automatically turns on the component and turns it off at the end of the duty cycle. An example of this is outdoor lighting. BMS system can create a schedule for external lights so that it switches then on in the evening (say 6.00 pm) and switches then off in the morning (say 7.00 am). The lights will operate within this cycle unless turned on or off manually by the building manager, operator or users.

BMS system monitors operation of various building systems and gather information about their energy or water consumption and performance efficiency (Lewis, et al., 2010). This helps in determining the amount of energy or water consumed by the system and whether it is operating at its design efficiency or if it has any defects that require repair.

This is a very important function of BMS system and components. The system controls operation of different building components by ensuring a balance between building conditions and occupant needs (Kumar, et al., 2013). When conditions in the building are not providing the desired thermal comfort and air quality, BMS system is able to actuate relevant components so as to adjust conditions to the setpoints (ClimateTechWiki, 2010). For example, when indoor temperature is high, BMS system turns on the chiller that circulates cool air into the building thus dropping temperature to the desired range or setpoint value. The system also optimizes start/stop time of various components. All these helps in controlling the operation of various building systems and the amount of energy or water they consume because they only operate when needed (Sustainable Focus, 2017).

BMS system optimizes performance of various building components by identifying any defects and notifying the building operator/manager about them. This helps in repairing or maintaining components on time, which prevents damage, unnecessary or high maintenance costs and energy or water wastage. Optimizing also helps in improving comfort of occupants because the components are always working at their optimal efficiency.

BMS system collects and stores all data pertaining the amount of energy or water a component consumes, history of its performance and efficiency, runtimes, downtimes, etc. This logged data and history provides useful information about components that are efficient or less efficient. The building operator or manager can easily retrieve the logged data and use it to analyze various performance parameters of any component that is included in the BMS system (Anon., 2009). 

Electrical Appliance Energy Consumption and Control

This is a major benefit of BMS system for building managers or operators. BMS system is able to create reports of all building components included in it. One of the main reports is energy report. This report shows energy consumption of every electrical or electronic system in the building. It indicates whether these systems are operating within or outside their design specifications. For example, a BMS report can show if the amount consumed by MVAC system is within the manufacturer’s range or not. Those operating outside their design ranges have to be repaired, upgraded or replaced so as to reduce energy wastage. Reports are mainly used to determine repair, maintenance, upgrade or replacement needs so as to lower energy consumption, save money and improve safety and comfort of occupants.

Sustainability has become a very important issue in today’s building and construction industry because of the industry’s environmental, economic and social. Because of technology, many people also want to live in buildings they can control from wherever they are whenever they want (Tariq, et al., 2012). This has made BMS installation very crucial in modern buildings (Schein, 2007). Below are some of the reasons why using BMS installation in buildings is necessary.

BMS ensures that all building components operate as desired and when needed. It ensures that MVAC system operates properly thus circulating fresh air at the setpoint temperature. This improves thermal comfort and air quality in the building. BMS installation also ensures that lights are switched on in occupied rooms. All these create a conducive environment for occupants either at home or in office, which improves safety, health and productivity of occupants (Ellis, 2011).

BMS installation helps to monitor performance of different equipment, devices and appliances in the building. As a result of this, BMS system is able to detect any defects or malfunction thus notifying the building operator or manager about the same early enough to prevent damage or inconvenience (Mohammad, et al., 2017). Once the notification is given, the building manager/operator is able to perform the necessary repairs, upgrades or replacements. In other words, BMS installation helps to correct problems before they occur. Additionally, BMS installation can be designed to create a maintenance schedule for each building component, device or appliance.

BMS system is able to monitor, control and report performance of all components installed and used in the building. Since all these activities are done by an automated system, the number of personnel required to manage operations of the building reduces (Pukite & Geipele, 2017). For instance, instead of hiring specialists to check defects in each individual component, the building manager/operator uses BMS system to identify components that require maintenance. This eliminates the staffs and time that could be needed to check maintenance needs of these components. The building manager/operator only has to hire a technician to repair the components but not to check defects since they are already identified.

As stated before, BMS installation helps to monitor and report performance of various components. This enables preventive maintenance that helps to keep systems in their best working conditions. When systems are operating within their design specifications, energy efficiency increases (ICONIC Plus, 2015).  

Plumbing Systems Monitoring and Control

There are various ways in which BMs installation enhances energy management. First, BMS installation ensures that systems, appliances or equipment in the building operate only when needed. This is achieved through duty cycles, operating hours and occupancy presence detection (Gul & Patidar, 2015). Second, BMS installation maintains all building components in their optimal working condition by enabling maintenance schedule and preventive maintenance. This prevents energy losses through faulty equipment. Third, BMS installation facilitates use of natural resources especially daylighting. The system enables dimming of lights when there is sufficient daylighting. All these reduces energy consumption in the building.

BMS installation reduces energy consumption through different approaches, some of which have been discussed above. Reduced energy consumption means that carbon emissions related to production and distribution of energy also reduces. This makes BMS system an effective strategy to promote green/sustainable building (Reffat, 2010).  

BMS installation reduces energy consumption of various equipment. It also lowers maintenance costs by repairing equipment before they get damaged. All these reduces overall operating costs of buildings.

BMS installation controls access to the building and monitors are entries, exits and other activities inside and around the building. The system restricts illegal entries or exits and notifies relevant persons about any security breach to take necessary actions. These improves overall security and safety of the building and its occupants (Advanced Control Corp., 2017).

BMS hardware performs several control functions. These functions ensure that each equipment, device or system operates within certain parameters thus providing the required indoor comfort level or working environment at minimum energy usage and greatest efficiency. Below are some of these control functions:

BMS hardware sets operation of various equipment in the building based on occupancy presence (occupancy time) because occupants significantly influence the amount of energy consumed (Azar & Menassa, 2012). If it is an office and the working hours are from 7.00 am to 4.00 pm, BMs hardware presets relevant equipment so that they can be operating within this period. The same applies to access control where BMS hardware allows access to specific areas in the building only when it is working hours.     

BMS hardware controls effects that external factors, such as atmospheric conditions, may have on the internal environment. For instance, when temperatures are too high outside, indoor temperatures are also expected to rise thus compromising thermal comfort of occupants. However, BMS hardware prevents this by switching on chiller control plant that circulates cool fresh air throughout the building. The same applies for luminaries where in case of dark clouds that inhibit use of natural daylighting, BMS hardware automatically switches lights on or increases their intensity to desired levels by the occupants.

BMS hardware uses proportional, integral and derivative (PID) control to ensure uniform performance of MVAC irrespective of fluctuating outdoor conditions or occupant needs. The hardware monitors and controls humidity, temperature, pressure and air flow rate inside the building maintaining desired indoor conditions irrespective of outside influence.  

BMS hardware is used to optimize start/stop times for various equipment and systems in the building based on predetermined scenarios or self-learned trend. This ensures that systems remain operational only during their duty hours. The same is also applied in controlling warm-up and cool-down processes.

Building Security and Access Control with BMS

BMS hardware has the capacity to regulate operation of equipment during the night. The system can identify equipment that should operate during the night and those that shouldn’t. For example, it ensures that lights in office spaces remain turned off during the night because these spaces remain unoccupied throughout the night. The same applies to several other equipment and devices such as HVAC system, televisions, etc.   

This is a very crucial function of BMS hardware. When people are going for holiday, most of their systems remain turned off. BMS software turns off HVAC system, indoor luminaries, lifts and escalators, plumbing system, etc. However, it turns on access control and security systems so that building owners or managers can monitor and be notified of any security threats. For this reason, building owners or managers simply use holiday programme setting to control systems that should be turned on or off during the holiday.   

There are times when equipment in the building should operate at optimum or below that so as to save resources without compromising occupant needs. BMS hardware is used to determine that. For example, when the intensity of natural light is adequate to provide necessary lighting in the building during the day, BMS hardware dims or switches off the lights. This ensures that lights only work at optimum when necessary or else they can work at a lower level than their design capacity. The same applies for HVAC system, plumbing system, etc. Therefore BMS hardware decides when an equipment system should operate at optimum on/off.

It measures different electrical parameters and adjust the equipment to ensure that it operates within its design specifications. For instance, if a HVAC system is designed to operate at a voltage not exceeding 2 kV, BMS ensures that this voltage is not exceeded or else it will shut down the system and send a notification about the same to the building operator/manager.

Fixed BMS hardware components are mainly categorized into: field/zone level, automation level, management level and enterprise level, as shown in Figure 2 below. Field/zone level comprises of switches, sensors, box controllers, FCU controllers, etc.; automation level comprises of discrete controllers, outstations, central stations; chillers, boilers, air handling units, power meters, lighting systems, fire systems, etc.; management level comprises of communication gateways, central station, etc.; and enterprise level comprises mainly of the internet for data transmission. BMS hardware components operate from the field/zone level upwards.

Figure 2: Categories of BMS hardware components

The various BMS hardware components and their operations are as follows:

DDC (direct digital control) units: they are programmable controllers used for measuring parameters, such as humidity, temperature, air flow rate, pressure, etc., that are used to control operation of MVAC system.

Sensors: these are devices for detecting different external stimuli, such as temperature, light intensity, pressure, humidity, gases or occupancy presence, and sending a signal to respective controllers. They are located in suitable positions to ensure accurate and real-time measurements.

Stand-alone controllers: these are devices designed to control operation of small-sized MVAC systems. They include optimizers and compensators, and can operate separately (without depending on BMS software). These devices are also not part of the communication link of BMS system.

Fire and Toxic Gas Detection and Alarm Activation

Actuators: they are devices used to adjust operation status of equipment based on signals they receive from controllers. For instance when smoke detectors identify presence of smoke or fire in the building, it is an actuator that initiates homing of lifts to the ground floor.

Outstations: they are devices with built-in programmable software for performing particular control functions. There are various outstations in a BMS system, each with a sub-control system, and connected to communication network of BMS. Outstations use outputs from stand-alone controllers, sensors and actuators.

Central station: it is a computerized unit that analyzes data received mainly from unitary controllers and outstations to generate outputs for adjusting operating parameters of equipment. It is BMS system’s main access point and can also be used for creating schedules and graphical schematics or sending logged data to the printer. It is part of BMS’s communication network.      

Programmable controller: this is a device that controls operation of a specific component based on pre-determined instructions, conditions or schedule.

Chiller plant control: used to control circulation of cool air in the building based on ambient temperature and occupant requirements.

Lighting control: used to control lighting intensity and on/off statuses.

Ventilation fan control: it is a unit used to control circulation of fresh air in the building so as to maintain good air quality throughout.  

Air handling unit (AHU): this is a unit for controlling various parameters affecting air quality, including temperature, humidity, pressure, air flow and toxic gases. Each AHU has a discrete DDC controller.

Modem: it provides data for transmission of data between various components of BMS system.

Serial printer: it is used for generation of alarms or reports.

Switch/bridge: it is used for expanding BMS network by enabling connection of 2 or more LANs.

User interface: it is a platform where users can enter inputs in form of values or commands, access data for purposes of extraction or manipulation, or create reports.

There are two main processes involved in installation of BMS fixed hardware system: planning and selection of cable wiring method.

This process entails three main activities: protocol selection, cable selection and topology. Discussions of these processes are provided below:

Protocol selection: this process involves identifying the local building codes and standards and installation rules and requirements for this kind of job. Various installation procedures are also analyzed and the best one selected. Resources required for the selected procedure, including equipment, materials, labour and time, are also evaluated.

Cable selection: the process entails selecting the best cables to be used from a wide range of cables available. The major categories of cables are metallic and non-metallic cables. The cables are selected after thorough analysis of their specifications, properties, availability, price, flexibility and suitability for the task.

Topology: the process entails identifying the specific components of BMS fixed hardware system, layout of the system and the sequence of installing this component. In this process, the overall network structure of the system is established, including the spatial and geometrical patterns. Another importance of this process is to ensure that BMS installation does not affect other existing or planned building services.

Lift and Escalator Control with BMS

Below are 6 cable wiring methods that can be used for installation of BMS fixed hardware system:

Cleat wiring: this is a very old wiring method and it entails fixing wooden, plastic or ceramic cleats with holes on walls, floors or ceilings then passing cables through the holes (Electrical Technology, 2015). The cleats hold the cables securely in place. This method is cheap and suitable for temporary installations. However, the appearance of final work is unimpressive.

Batten wiring: this method involves using plugs and screws to fix wooden battens on floors, walls or ceilings then passing cables through the battens. The battens have link clips fixed on them using nails. These links are used for securing cables onto the battens (Raina, 2007). The total cost of this method is low but the appearance of final work is unimpressive especially for modern buildings.

Metal sheathed wiring: in this method, insulated conductors covered with aluminium-lead alloy are used. The cover basically protects cables from moisture, corrosion and physical damages. The wiring process is the same as the one for batten wiring. The appearance of final work is also unimpressive especially for modern buildings.

Casing and capping wiring: this is also an old method of wiring. It involves fixing wooden casings containing parallel grooves onto floors, walls or ceilings using screws the passing cables through the casings. After that, wooden caps having grooves are used to cover (cap) the cables (Thyagarajan, 2007). The mien of final work is also unimpressive.

Trunking: this is a method where PVC trunking conduits are fixed on floors, walls or ceilings using plugs and screws then cables are passed through the conduits (Electrical Installation Wiring Pictures, 2010). The method is becoming very common nowadays but some people do not prefer it because of the appearance of the conduits, which remain exposed on the surface where they are fixed. There are also different types of trunking systems suitable for industrial, commercial and domestic environments (Schneider Electric, 2017).    

Conduit wiring: this is the most common method of cable wiring today. Conduit wiring method can either be surface conduit wiring or concealed conduit wiring. The former involves making indentations on surfaces of floors, walls or ceilings, placing conduits in these indentations and securing them using plugs.  Cables are then passed through the conduits. The conduits containing cables are properly secured in the indentations but they remain visible i.e. uncovered (Sree, 2012). In concealed conduit wiring, the conduits and cables are fixed the same way as in surface conduit wiring but after placing the cables, the indentations are plastered so as to cover the conduits containing cables (Happho, 2017).

Each of the above methods has advantages and disadvantages. But based on criteria for selecting cable wiring methods for modern buildings, concealed conduit wiring method is the most suitable method. In this method, cables are protected against physical damages, corrosion, moisture and other external factors, making it suitable for long-term installation. Most importantly is that the look of final work is spectacular, which is a fundamental factor in modern buildings.

Additional Functions of BMS

Chiller plant control is the MVAC installation selected for discussion in this question. Control logic flow chart of a chiller comprises of two fundamental processes: startup procedure and shutdown procedure. As the names suggest, startup procedure entails processes initiated when a chiller plant control is being started while shutdown procedure comprises of processes followed when the system is being halted. These processes are discussed below

A chiller plant control gets activated when temperature inside the building goes beyond the desired temperature range (set point). When this happens, the chiller plant control receives a signal from relevant sensors then it gets started. It is worth noting that chiller plant control starts only if the temperature is above the set point. When it starts, the first action is to close and open the CWDD (cooling-water drain device) and CTS (city-water switch) respectively. This allows city water to be supplied to the cooling tower so that subsequent processes can follow. This process will only continue if within 3 minutes, cooling-water tank’s water level probe will have detected the water or else the process stops. After water has been detected in the cooling-water tank, CHWP (chilled-water pump) gets started and immediately the status of water starts being monitored by a device called chilled-water flow detector. When this device detects adequate chilled water, CWP (cooling-water pump) starts operating to supply cooling water. At the same time, a dilute solution is supplied by the solution pump from the absorber to regenerators. This process continues until when chilled-water’s temperature reaches or exceeds the set point. This leads to opening of SV (steam valve) thus allows supply of thermal energy to the HTRG (high-temperature regenerator). This procedure is presented in the control logic flow chart shown in Figure 3 below

Figure 3: Control logic flow chart of chiller plant control’s startup procedure

This process comes after startup process and when indoor temperature has been raised to the desired level or setpoint. The process starts when chiller plant control receives a signal of the aforementioned information from the relevant BMS components. The process starts by closing of steam valve (SV) followed by mixing of regenerators’ hot concentrated sorbent solution and absorber’s cold and dilute solution until when temperature of the sorbent solution in high-temperature generator decreases to the desired level. After that, steam pump closes followed by regenerator pump, cooling-water valve, cooling-tower fan, cooling-water pump and the last to close is the chilled-water pump. Figure 4 below is a diagram showing the control logic flow chart of shutdown procedure of a chiller plant control.

Figure 4: Control logic flow chart of chiller plant control’s shutdown procedure

There are numerous BMS control point schedules. Some of these include: extract fans (fans’ start/stop, fans’ status, indication of trip alarm, VSD enable/disable, VSD speed feedback, VSD speed control, VSD fault and VSD run status), secondary chilled water pumps (run status of the pump, pumps’ start/stop, trip alarm indication of the pump, manual switch position indicator, variable speed units’ pump speed, discharge pressure of pump and supply & return water pressure), fresh air handling units (VSD fault, VSD enable/disable, speed control of VSD, speed feedback of VSD, fire alarm, supply air temperature, pressure of supply duct, supply air temperature, ambient humidity and temperature, filter status, start/stop command of fan, trip status of fan, run status of wheel, run status of VSD, status of fan trip, duct humidity and indicator of air flow), and fan coil units (FCUs) (set point of room temperature, FCU fan run status, and space temperature monitoring).  

Chiller plant control is a BMS component that plays a major role in monitoring and controlling temperature in the building. This control system is a closed loop system and measures variables such as pressure, temperature, flow, humidity, etc. Its basic elements are sensors (temperature sensors, pressure sensors, humidity sensors, electronic sensors, flow sensors, liquid level sensors, air flow sensors and voltage sensors), controllers (set point converter, compensation unit, temperature controller, enthalpy controller, humidity controller and universal controller) and control devices (actuators, control valves, dampers, pumps, fans, cooling coils and heating coils), as shown in Figure 5 below. The main function of this system is to maintain temperature at predetermined set point.

Figure 5: Block diagram of chiller plant control

The operation of a chiller plant control is facilitated by flow of information or signals from one element to another. The system has several control points that are designed to monitor, control and manage thermal content and air quality in the building. Figure 6 below is a schematic diagram of a chiller plant system. The system comprises of different components, including analog input (AI), analog output (AO), digital input (DI) and digital output (DO). AI is used to show parameters such as temperature, humidity, water flow, tank level, air flow, energy, current, pressure and voltage. AO of the system shows valve control of chilled water and fan speed control. DI indicates several parameters including status of the system (on or off, open or close, etc.), system alarm and trip, among others. DO is used to indicate command of the system, which include on or off and open or close. This system uses direct digital controls (DDC) i.e. t sends signals using electrical pulses. Some of the advantages of DDC include: they are very precise, flexible ad do not experience controller drift.

Figure 6: Schematic diagram of chiller plant system

Once the temperature is outside the set point range, immersible temperature sensors (ITS) take measurements of this temperature and transmits a signal to controllers. The controllers synthesize this signal so as to determine whether the temperature is too low or too high and by how much. The information generated by the controllers is then sent to control devices that regulate relevant components including actuators, control valves, dampers, pumps, fans, cooling coils and heating coils to bring temperature to the desired set point.

The diagram basically provides an outline on how movement of air is controlled from entry to exit through different points. In this diagram, AI includes duct temperature sensors and room temperature sensors; AO includes hot & chilled water valves; DI includes supply fan, return fan and smoke detector; and DO includes supply fan and return fan (Electrical Knowhow, 2012).

The on sequence starts by opening the butterfly valve of the chiller then checking the open status of the butterfly valve. Thereafter, the primary pump is switched on then its status is checked. The secondary pump is enabled and its status checked. After that, the chiller is started. For the off sequence, the first step is to stop the chiller followed by disabling the secondary circuit. This is followed by switching off the primary pump then the butterfly valve of the chiller is closed.

BMS system comprises of numerous components, each with a specific task. Some of the components are: operator’s terminals, DDC units, switch, gateways, modem, serial printer, bridge/switch, user interface, software, standalone controllers, plug-in keypad, and touchscreen, among others. All these components are integrated into one system and are properly synchronized so that discrete components do not affect each other (Adowia, 2012). The other components and equipment that are also part of BMS system include: HVAC system (air handling unit, chiller, motorized valve, chilled water pump, air temperature sensor or thermostat, motorized air damper, extract fan and fan coil), security system (bypass switch, motion sensor, CCTV cameras and alarm system), access control, lift and escalator, lighting system, etc.  

Operating schedule: BMS system has varied operating schedules. Some systems such as access control, security system and fire services systems usually operate 24/7 because their operation is not dependent on occupancy presence. As a matter of fact, building owners/operators want to be notified of any security threats or fire risks regardless of whether they are within or away from the building. However, most of the other systems operate less than 24 hours, depending on BMS control strategies for each of them. Majority of these systems operate when necessary so as to conserve energy. Some of the BMS control strategies used are: operation hours, occupancy presence, setpoints, duty cycle and night cycle, among others. For example, lighting schedule can be controlled by operation hours, occupancy presence or setpoints. If lighting system is programmed to operate from 6.00 am to 6.00 pm, lights will remain turned on within this duration irrespective of whether the spaces are occupied or not. Alternatively, occupancy presence can be used as a control strategy for lighting schedule by ensuring that lights are only turned on when a space is occupied. Also, the lighting can be programmed such that lights turn off when daylight intensity reaches the lowest or predetermined lux intensity required by occupants.

Chilled water pumps – its components and specifications include: start/stop of pumps, run status of pumps, trip alarm indicator of the pump, manual switch indicator, pump speed button, pump discharge pressure and supply & return water pressure.

Extract fans – its components and specifications include: start/stop button, trip alarm indicator, fan status, variable speed drive (VSD) speed control, VSD enable/disable, VSD sped feedback,, drive fault for variable speed, and VSD run status.

Air handling units (AHU) – components and specifications include: AHU fan start/stop, AHU fan run status, filter status, AHU switch indicator, VSD speed feedback, VSD speed control, VSD enable/disable, trip alarm of reheat coil, VSD fault, VSD run status, etc.

Lighting control system – its main component and specification is the lighting control system’s full interface.

Fan coil units (FCU) – some of its components and specifications include: FCU fan run status, set point of room temperature, and FCU speed switches.

Fire alarm system – some of its components and specifications include: status of power on/off and common fault alarm.  

CCTV system – some of its components and specifications are: status of power on/off, and common fault alarm.

Access control system – its components and specifications include: status of power on/off and common fault alarm.

Close control unit: components and specifications include: run status of fan, unit start/stop, filter status, on/off temperature of cooling coil air, on/off temperature of reheat coil air, on/off status of humidifier, space humidity, space temperature, humidity set point, etc.

BMS equipment schedule for installation also encompasses various details of the equipment including: description of the equipment, model number, name of manufacturer and origin.Examples of point schedule and controller points of a chiller plant are as shown in figure 9 and 10 below:

The schedules for installations for various components of BMS equipment and components are as follows:

Fan coil unit: input/output settings within the DDC program are configured; DDC program is downloaded to the DDC controller, BMS graphics are used to check space temperature; the fan’s three speed controls status are checked; and the valves’ operation is checked to change temperature set point.   

Chilled water pumps: DDC program’s input/output settings are checked; DDC program is downloaded to DDC controller; pressure sensor’s readings are checked using BMS graphics; and the VFD feedback readings are checked using BMS graphics.

Fresh AHU with carbon dioxide: DDC program’s input/output settings are configured; DDC program is downloaded to DDC controller; BMS graphics are used to check the sensor’s external humidity & temperature, supply air temperature, duct temperature and the status of fan’s speed control; the valve actuator’s operation is checked; and the carbon dioxide sensor level and feedback are checked via BMS graphics.

BMS software plays a very crucial function in BMS system. It is in the BMS software where a lot of data is processed to create the required information used for controlling, monitoring, optimizing and reporting. The software contains a variety of tools used for performing different tasks such as data logging, alarm generation, graphic presentation, network communication, energy monitoring, energy management, maintenance program and reporting, among others.

Building managers/operators retrieve very useful information from BMS software. They use this information to identify and implement effective strategies of improving energy efficiency and management. Additionally, it is BMS software that initiates controls or actions for creating desired conditions in the building and improving safety. Therefore BMS software is very useful in improving comfort of occupants and saving energy.

There are different statements that are generated by BMS software. Below are examples of these statements:

Indoor temperature is too high – the BMS system turns on the chiller plant control so as to circulate cool air into the building. If the statement is “indoor temperature is too low”, the BMS will turn on the heating system so as to supply warm air into the building.

Sufficient daylighting – the software can provide this statement if the intensity of daylight exceeds the minimum lux level needed in the building. Here, BMS system automatically turns off luminaries until when daylight intensity drops to below the required lux level.  

No occupancy presence – the system turns off luminaries. If no occupancy presence statement is provided at the start of off-duty cycle, BMS system may also turn off other equipment such as MVAC and some electrical and electronic devices.

Equipment defect – the BMS system notifies the building owner or operator so as to carry out an inspection and the necessary repair works. But if the malfunction is likely to cause major problems, the BMS system may turn it off and simultaneously notify the building owner/operator.

Energy inefficiency – this is provided when an equipment or system is consuming more energy than its manufacturer’s design values. The system notifies the building owner/operator about the same so that the equipment may be inspected and repaired to improve its energy efficiency.

Holiday mode – comes when occupants of the building are going for holiday. It is followed by switching off particular systems such as luminaries, MVAC systems, some electrical appliances, lifts and escalators, etc.

Point editor is a very critical element of BMS software. Its basic function is encoding BMS system. It provides an interface where the user applies a language understood by the BMS system. Some categories and examples of point editors: command, calculation, schedule, status, control, set point, analogue output, holiday, and meter point editor, among others.     

Commands in BMS system are given in a specific programming language, such as the basic C++ language. These commands can be simple logical sentences that result to specific control actions. One example of a logical sentence is as follows: if there is no occupancy presence in a room, switch off luminaries until when an occupant walks in. Another logical statement is: if indoor temperature is <15°C, turn on heating system until. Let it remain switched on until indoor temperature increases to between 20°C and 26°C.

Commissioning of BMS installation entails testing various components of the system to ascertain that they are in proper working condition before handing over the system to the building owner or operator (Cullick, 2010). A chiller plant control plays a major role in maintaining desired indoor temperatures and so is its testing and commissioning processes (Kumara, et al., 2016). Below are commissioning procedures for this system:

Operation procedures: this involves checking and confirming that the layout of the control system and its operation comply with the design control logic and schematic drawings (Statement, 2015).

Control elements: this is where all control elements, particularly sensors, of the chiller plant control system are checked to confirm that they meet the desired range (Woehrle, 2011). The elements checked include: sensor output, digital signal, actuators and alarm signal of the sensor.

Control loop: this involves checking the control loop of the chiller plant control to confirm that it is in accordance with the design logic flow chart and schematic drawings (Zak, 2012).

Cables: this entails checking and confirming proper cabling between direct digital control (DDC) controllers and chiller control plant’s sensors.

Software installation: this is where the BMS software for the chiller plant control is tested to confirm that its database and graphics are working correctly. 

Graphic presentations: here, graphic presentations are tested on the screen to ensure that they are visible and logical.  

Data transmission: this is a functional check that entails checking communication network of the BMS (Method Statement HQ, 2012).   

Troubleshooting: this entails creating a chart to document possible causes of problems. Causes with high likelihood of causing problems are registered at the top while those with less likelihood are registered at the bottom of the chart. 

Reports: a report must be prepared at the end of the testing procedure to document all findings. Any areas that need to be improved are highlighted and general recommendations are provided on how to improve the system’s efficiency. The system should only handed over to the building owner or operator if it is in proper working condition (Hyman, 2015).  

The final commissioning procedure starts by configuring the input/output settings in the direct digital control (DDC) program. This is followed by downloading the DDC program and installing it in the DDC controller. The next step is checking the position and feedback of butterfly valve, pressure sensor of chilled water at supply & return header, temperature sensor, water flow switch and external humidity & temperature sensor via BMS graphics. The last step is checking the valve actuator’s open/close (operation) based on temperature set point adjustment. Below are some of the commissioning schedules of a BMS chiller plant control

But before the BMS system is handed over to the owner, the following verifications and tests have to be completed:

Full installation verification: this process entails evaluating the BMS components and the system as a whole so as to ensure that it complies with the specifications, requirement, regulation and conditions. The main objective of full installation verification is to confirm whether the BMS system contains all the components to enable it meet the user’s operational needs.

Operational performance test: this test is done to confirm whether the BMS system is able to operate within the anticipated conditions or limits and attain expected results. For instance, is the system able to react automatically to changes in external temperature or indoor occupancy so as to turn air conditioning or lighting systems on/off? This test is very useful in establishing the reliability of the system, possibility of risks, and ease of control before it is handed over to the user (Fahimirad, et al., 2015). 

Function performance test: this is the test carried out so as to determine how the operation of one component affects others or the overall BMS system. The test also helps in determining whether each component of the BMS system is able to perform its intended purpose effectively.   

BMS installations are very useful in creating performance reports indicating operation of different systems and their efficiency. These reports are created from data gathered by different measurement devices installed in the building. The reports can be created by the BMS software or logged data can be copied from the system and transferred to another computer for generation of these reports. Therefore when building owners, managers or operators want to know the performance of a particular equipment or system, they simply obtain its report for analysis (Sinopoli, 2010).  

It is important to note that BMS collects data of all systems and devices connected to it at all times. The system collects data from MVAC system, plumbing system, lighting system, electrical appliances, lifts and escalators, fire services system, security system and access control system, among others (Paola, et al., 2014). Each of these systems has a specific file in which the data is stored. Since the data is collected 24/7, the total volume is very large. For this reason, it may be very difficult and time consuming to analyze raw data and make useful conclusions about the performance of different building systems and equipment. This is the reason why performance reports are very important.

Performance reports are generated from data collected by BMS installations. The data comprises of very useful parameters such as energy consumption, runtimes, downtimes, on-times, etc. Therefore it is very important to ensure that the data is collected accurately. For this to be achieved, BMS software and hardware components should be of appropriate specifications, the BMS system must be installed properly, measurement devices such as sensors should be installed in proper locations, and the BMS system has to be tested regularly to ensure that it is functioning properly.           

After measuring the useful parameters, the collected data is logged and stored into respective files. The logged data is basically a history record showing the trend of values of different systems or equipment. This trend provides a general representation of the energy consumption of different systems in the building. The trend is also useful for the BMS system in relation to self-learning on performance of different equipment. BMS software uses integrated equations and formula and the logged data to calculate more relevant values, such as cooling and heating loads, energy consumption, equipment efficiency, etc. The values calculated are then used to generate reports, which comprise of text and graphics.

BMS reports are very useful as they make it easier to analyze performance of various systems in the building. For example, a report can provide a graph, histogram or pie chart showing energy consumption of a HVAC system over a few months. If the report shows a gradual increase in energy consumption, this trend my mean that efficiency of the HVAC system has been decreasing hence the system has to be repaired, improved or replaced. Generally, BMS reports help in identifying strategies for improving performance of different systems and equipment in the building.   

BMS installations have various settings for modifying and adjusting different parameters. The following are some of these settings:

PID (proportional integral and derivative) control: this setting controls the MVAC so as to maintain internal air quality and temperature within the desired range irrespective of outside influence. With this setting, BMS installation is able to maintain desired indoor temperature and air quality even if outside temperature, humidity, pressure and air speed keep on fluctuating.

Lux level setting: the setting is used to turn luminaries on/off during the day so as to capitalize on natural daylighting. When daylight intensity exceeds a particular level, the setting automatically turns off luminaries, and vice versa.

Temperature setting: this setting controls temperature to ensure that indoor temperature is always within the desired range. When temperature rises above the desired range, the setting switches off heating system and switches on cooling system (such as chiller). This level is maintained until when indoor temperature drops to the desired range and the setting automatically switches off the cooling system. A similar but reverse process happens when indoor temperature drops below the desired range. Therefore temperature setting ensures that there is no overcooling or overheating in the building. Additionally, this setting helps in ensuring that systems operate within their design temperature thus preventing damage.       

Summer/winter setting: the high temperatures during summer usually eliminates air heating needs in buildings so this setting turns off air heating systems and turns on air cooling systems. During winter, air cooling is not needed and therefore the setting turns of air cooling systems and turns on heating systems. This happens automatically at the start and end of each season.

Thermal setting: the setting is used to regulate thermal comfort in the building. When heat content exceeds or drops below setpoint, the setting automatically activates the ventilation fan until enthalpy returns to the desired level.  

Night cycle/purge setting: the setting is used to turn off or reduce operating level of some equipment and fixtures in the building during the night when the building is unoccupied. For instance it turns of lights and MVAC system.

Start time and stop time optimization setting: the setting optimizes the time when a system or equipment should start or stop operating (Masoero & Silvi, (n.d.)). Based on predetermined duty cycles or operating hours, the setting automatically turns on equipment at start time and turns it off at top time.

Equipment startups: this setting is used to create desired environments some time before rooms are occupied. For instance if reporting time in an office is 6.00 am, the settings can turn on MVAC/HVAC system at around 5:45 am so as to adjust indoor air temperature and thermal comfort to the desired level before arrival of staffs.       

The above settings are very useful in meeting occupant needs at the lowest energy usage.

BMS data and reports are very important in analyzing performance of different systems or equipment in the building. They make it easier to identify defects and correct them early so as to avoid total damage or high reactive maintenance costs. Buildings without BMS installations usually rely on fixed maintenance or reactive maintenance method. Fixed maintenance is where a system or an equipment is maintained based on a predetermined schedule that is recommended by the manufacturer. This can be after every two weeks, one month, quarterly or annually. The method is not suitable for modern buildings because an equipment can fail at any time resulting to inconveniences (Iveta, 2017), damages and higher maintenance costs. Reactive maintenance is a method where an equipment is repaired when it fails. This method is also not reliable because it causes inconvenience and maintenance costs are very high. PPM is the best method to use because it enables repair of equipment before they get damaged or fail, prevents inconveniences (Au-Yong, et al., 2014) and has low maintenance cost. Therefore once BMS data and reports are obtained, they can be used to perform PPM.

The general procedure of carrying PPM using BMS data and reports is as follows:

The first step is to analyze the BMS data and reports so as to understand different parameters, including trend, runtimes, downtimes, etc. of the system being investigated (Staller, 2015). These parameters can be collectively referred to a statuses and they help in understanding performance efficiency of the system based on the trend determined. This analysis establishes whether the system is efficient or not, based on its operating conditions and efficiency. For example, if energy consumption by an electrical appliance is higher than anticipated then the appliance is operating inefficiently thus it has to be repair or replaced.

The second step is to create a hierarchy of maintenance needs based on their priority (eMaint, 2016). Maintenance needs have different magnitudes based on the impacts they have on the operating costs, safety and comfort of its occupants. This makes it necessary to prioritize the maintenance needs identified. The needs can be categorized as primary maintenance needs, secondary maintenance needs and tertiary maintenance needs. Primary maintenance needs are those that can lead to significant damage or complete breakdown of an equipment in case it is not repaired immediately. They include repair of high-heat valves, pumps, boilers or high-pressure valves for a MVAC system. Secondary needs are those that do not cause significant problems even if the equipment fails. An example is a broken duct in an MVAC’s pipework.

The third step is to hire a specialist for inspecting the systems or equipment that needs to be maintained (Micromain Building Technology, 2017). It is worth noting that these systems or equipment were identified in the first step using logged data and BMS reports. The specialist, such as a trained and experienced technician, uses a checklist schedule to determine specific components of the system that needs to be repaired. All defects for each system are identified and evaluated.

The fourth step is to create a PPM schedule that includes specific strategies that will be used to rectify all defects identified. Here, the technician outlines the defects, materials required for maintenance, maintenance methods to be used and the specific program to be followed.

The fifth step is to carry out actual maintenance by following the program developed in the preceding step. Each component defect listed on the PPM schedule is rectified and tested. Specific activities in this process may include cleaning, applying paint, lubricating or replacing with new components. 

The final step is to test the repaired systems, prepare a report that includes a follow up procedure and hand them over to the building owner or operator.

A lot of energy in buildings is used for heating, cooling, ventilation and air conditioning. BMS data and records can be used to set controls, based on building conditions, outside influence and occupant requirements, so that there is no overheating or overcooling. This means that heating, cooling, ventilation and air conditioning systems will only operational when adjusting temperatures to the desired range after which they automatically turn off (Rezeka, et al., 2015).

BMS data and reports are used for self-learning purposes, which helps in determining duty cycles of various equipment or systems in the building. Duty cycle basically refers to the time when an equipment or system is required to be functional. In a typical building such as an office, most of the equipment/systems are only used during working hours. This includes lights, computers, televisions, printers, photocopiers, scanners, MVAC system, chiller, etc. Leaving such equipment or systems switched on when going home is a waste of energy. Therefore BMS data and report is used to determine operating hours of various equipment/systems and set controls that automatically turn off particular equipment/systems during off-working hours, including weekends and public holidays.

There are times when an equipment should operate at its optimum and there are times when this is not necessary. Using BMS data and reports to analyze performance trend of various equipment/systems (Gallachoir, et al., 2007), it is possible to determine when each equipment/system operates at its optimum. This information should be used to optimize BMS system so that equipment/systems operate at optimum (optimum on) only when necessary. As a result, a lot of energy will be saved at the time when equipment or systems are operating at optimum off. This helps to significantly reduce energy wastage. 

BMS data and reports should be used to optimize BMS system such that it synchronizes with daylighting and natural ventilation. This ensures that when daylight intensity reaches the required lux level to provide ample brightness, luminaries get automatically switched off. The same applies to MVAC system where the system automatically turns off when natural ventilation provides the required indoor temperature and thermal comfort. This helps in reducing the amount of energy consumed by luminaries.

This is a very crucial strategy of improving energy efficiency management in buildings. Modern buildings have numerous systems that consume large amounts of energy (Clark, 2012). Any inefficiency of these systems results to loss of significant amount of energy. Among the best strategies of avoiding inefficiencies is preventive maintenance that is enabled by intelligent building automation (Anon., 2010). Since BMS analyzes and records performance of each system, BMS data and reports is used to develop maintenance schedules for each system and also notify the building owner or operator when a system malfunctions or develops a defect. These defects are rectified immediately keeping the system functioning at its optimum efficiency resulting to high energy efficiencies and savings.         

BMS data and reports are also used to determine the energy consumption and trends of each equipment or system in the building. Building owners or operators can use this information to categorize equipment/systems based on their energy consumption volume and efficiencies. The relevance of this information is that it can be used to prioritize maintenance or upgrade needs. In this case, equipment/systems that consume the greatest percentage of energy should be maintained or improved first to achieve high energy savings.

References

Adowia, O., 2012. Facility manager at Al-Turki Towers [Interview] 2012.

Advanced Control Corp., 2017. Advantages of building management systems. [Online]
Available at: https://advancedcontrolcorp.com/blog/2017/04/advantages-building-management-systems/
[Accessed 28 August 2017].

Anon., 2009. Development of intelligence analytic models for integrated building management systems (IBMS) in intelligent buildings. Intelligent Buildings International, 1(1), pp. 5-22.

Anon., 2010. Wang, S.. New York, NY: Taylor and Francis Group.

AutomatedBuildings.com, 2010. Benefits of lighting control integrating DALI and BACnet. [Online]
Available at: https://www.automatedbuildings.com/news/dec10/articles/intesis/10129012606intesis.html
[Accessed 30 August 2017].

Au-Yong, C., Ali, A. & Ahmad, F., 2014. Improving occupants' satisfaction with effective maintenance management of HVAC system in office buildings. Autom. Constr., Volume 43, pp. 31-37.

Azar, E. & Menassa, C., 2012. A comprehensive analysis of the impact of occupancy parameters in energy simulation of office builings. Energy Build, Volume 55, pp. 841-853.

Clark, J., 2012. BMS and the data center. [Online]
Available at: https://www.datacenterjournal.com/bms-and-the-data-center/
[Accessed 29 August 2017].

ClimateTechWiki, 2010. Building energy management systems (BEMS). [Online]
Available at: https://www.climatetechwiki.org/technology/jiqweb-bems
[Accessed 30 August 2017].

Cullick, H., 2010. HVAC commissioning checklists. [Online]
Available at: https://www.dylanmechanical.com/assets/commissioning-checklists-05242010.pdf
[Accessed 28 August 2017].

Dilouie, C., 2009. Integrating lighting and building control. [Online]
Available at: https://lightingcontrolsassociation.org/2009/05/09/integrating-lighting-and-building-control/
[Accessed 30 August 2017].

Electrical Installation Wiring Pictures, 2010. Electrical trunking installation pictures. [Online]
Available at: https://electricalinstallationwiringpicture.blogspot.co.ke/2010/03/electric-trunking-install-picture.html
[Accessed 30 August 2017].

Electrical Knowhow, 2012. HVAC control systems and building automation system. [Online]
Available at: https://www.electrical-knowhow.com/2012/04/hvac-control-systems-and-building.html
[Accessed 30 August 2017].

Electrical Technology, 2015. Different types of wiring systems and methods of electrical wiring. [Online]
Available at: https://www.electricaltechnology.org/2015/09/types-of-wiring-systems-electrical-wiring-methods.html
[Accessed 30 August 2017].

Ellis, I., 2011. Exploiting the full potential of a building-management system. [Online]
Available at: https://www.modbs.co.uk/news/archivestory.php/aid/8851/Exploiting_the_full_potential_of__a_building-management_system.html
[Accessed 28 August 2017].

Elzarka, H., 2009. Best practices for procuring commissioning services. Journal of Management in Engineering, 25(3), pp. 155-164.

eMaint, 2016. How to design a preventive maintenance program. [Online]
Available at: https://www.emaint.com/design-a-preventive-maintenance-program/
[Accessed 29 August 2017].

Fahimirad, M., Farzad, S., Moghaddam, S. & Saremi, H., 2015. A three-stage scenario based operational performance test approaches for production capacity enhancement: Case study on the 5th refinery of South Pars Gas Complex in Iran. Journal of Natural Gas Science and Engineering, 27(2), pp. 1758-1770.

Gallachoir, B., Keane, M., Morrissey, E. & O'Donnell, J., 2007. Using indicators to profile energy consumption & to inform energy policy in a university: a case study in Ireland. Energy Build, Volume 39, pp. 913-922.

Gao, R., Su, Y. & Ye, B., 2014. Rsearch on construction and analysis of intelligent building management system. Bio Technology: An Indian Journal, 10(17), pp. 9683-9687.

Greener Live Performances, (n.d.). Building management systems (BMS) for venues. [Online]
Available at: https://greener.liveperformance.com.au/uploads/pages/10/building_management_systems_info_kit_for_venues.pdf
[Accessed 30 August 2017].

Gul, M. & Patidar, S., 2015. Understanding the energy consumption and occupancy of a multi-purpose academic building. Energy and Buildings, Volume 87, pp. 155-165.

Happho, 2017. How to install concealed conduit electrical wiring system properly?. [Online]
Available at: https://www.happho.com/install-concealed-conduit-electrical-wiring-system-properly/
[Accessed 30 August 2017].

Hyman, L., 2015. Commissioning chilled water TES systems. [Online]
Available at: https://www.puretemp.com/stories/commissioning-chilled-water-tes-systems
[Accessed 28 August 2017].

ICONIC Plus, 2015. BMS benefits, control systems strategies, building technologies for intelligent buildings. [Online]
Available at: https://www.linkedin.com/pulse/bms-benefits-control-systems-strategies-building-intelligent-plus
[Accessed 29 August 2017].

Iveta, P. &. I. G., 2017. Different approaches to building management and maintenance meaning explanation. Procedia Engineering, Volume 172, pp. 905-912.

Kumara, W., Waidyasekara, K. & Weerasinghe, R., 2016. Building management system for sustainable built environment in Sri Lanka. Built Environment Project and Asset Management, 6(3), pp. 302-316.

Kumar, S., Rajwar, J. & Thakur, A., 2013. Building management system using PLC and SCADA. International Journal of Scientific & Engineering Research, 4(5), pp. 217-219.

Lewis, A., Riley, D. & Elmualim, A., 2010. Defining high performance buildings for operations and maintenance. International Journal of Facility Management , 1(2), pp. 1-16.

Makarechi, S. & Kangari, R., 2011. Significant parameters for building automation performance. International Journal of Facility Management, 2(1), pp. 1-25.

Masoero, M. & Silvi, C., (n.d.). Building energy management systems (BEMS) control strategies for air conditioning efficiency , Cardiff: AUdiTAC.

Method Statement HQ, 2012. Tetsing & commissioning method statement for building management system BMS. [Online]
Available at: https://methodstatementhq.com/testing-commissioning-method-statement-for-building-management-system-bms.html
[Accessed 28 August 2017].

Micromain Building Technology, 2017. How to set up a preventive maintenance plan. [Online]
Available at: https://www.micromain.com/set-up-preventive-maintenance-plan/
[Accessed 29 August 2017].

Modern Building Services, 2016. Interfacing lighting-control and building management systems. [Online]
Available at: https://www.modbs.co.uk/news/archivestory.php/aid/15359/Interfacing_lighting-control_and_building_management_systems.html
[Accessed 30 August 2017].

Mohammad, A., Ameen, M., Abdul.M.H. & Muizz, O., 2017. Challenges to the implementation of building management systems in Saudi Arabia. Built Environment Project and Asset Management, 7(2), pp. 130-142.

Nadeau, R., (n.d.). Chiller startup & shutdown: worth doing right. [Online]
Available at: https://digital.bnpmedia.com/publication/?i=110002&article_id=1051680&view=articleBrowser&ver=html5#{%22issue_id%22:110002,%22view%22:%22articleBrowser%22,%22article_id%22:%221051680%22}
[Accessed 28 August 2017].

Paola, A. et al., 2014. Intelligent management systems for energy efficiency in buildings: a survey. ACM Computing Surveys, 47(1), pp. 13-50.

Pukite, I. & Geipele, I., 2017. Different approaches to building management and maintenance meaning explanation. Procedia Engineering, Volume 172, pp. 905-912.

Raina, K., 2007. Electrical design estimating and costing. New delhi: New Age International.

Reffat, R., 2010. Integrating intelligent building technologies: a means for fostering sustainability. Riyadh, King Saud University.

Rezeka, S., Attia, A. & Saleh, A., 2015. Management of aair-conditioning systems in residential buildings by using fuzzy logic. Alexandria Engineering Journal, 54(2), pp. 91-98.

Schein, J., 2007. An information model for building automation. Automation in Construction , 16(6), pp. 125-139.

Schneider Electric, 2017. Multiple solutions for flexible working environments. [Online]
Available at: https://www.clipsal.com/Trade/Products/Cable-Management/Installation-Systems/Trunking-Systems
[Accessed 31 August 2017].

Sinopoli, J., 2010. Smart buildings systems for architects, owners and builders. Burlington, MA: Butterworth-Heinemann.

Sree, 2012. Types of internal wiring. [Online]
Available at: https://way2science.com/types-of-internal-wiring/
[Accessed 30 August 2017].

Staller, K., 2015. Six steps to design a preventive maintenance program. [Online]
Available at: https://www.plantengineering.com/single-article/six-steps-to-design-a-preventive-maintenance-program/15dc84630bc8dc979f8a1d9bc989cdc3.html
[Accessed 29 August 2017].

Statement, S. W. M. o., 2015. Precommissioning & Commissioning procedure for building management systems BMS. [Online]
Available at: https://safeworkmethodofstatement.com/precommissioning-commissioning-procedure-for-building-management-system-bms/
[Accessed 28 August 2017].

Sustainable Focus, 2017. Energy solutions. [Online]
Available at: https://www.sustainablefocus.com.au/energy-efficiency/
[Accessed 30 August 2017].

Tariq, W. et al., 2012. Building management system for IQRA University. Asian Journal of Engineering, Sciences & Technology, 2(2), pp. 106-109.

Thyagarajan, T., 2007. Engineering basics: electrical, electronics and computer engineering. New Delhi: New Age International.

Wang, S., 2010. Intelligent buildings and building automation. Nw York: Taylor and Francis.

Woehrle, M., 2011. Commissioning from a contractor's perspective: providing value to the owner. [Online]
Available at: https://www.contractingbusiness.com/archive/commissioning-contractors-perspective-providing-value-owner
[Accessed 29 August 2017].

Wong, J. & Li, H., 2009. Development of intelligent analytic models for integrated building management systems (BMS) in intelligent buildings. Intelligent Buildings International, 1(1), pp. 5-22.

Zak, P., 2012. Control sequence for chilled water systems. [Online]
Available at: https://www.csemag.com/single-article/control-sequences-for-chilled-water-systems/2eb1feb85d57006c05373f54d9a37eeb.html
[Accessed 28 August 2017].

Controlling and automation