*Continuous dimming* is a continuous adaptation of the luminous flux of the light source(s) in function of external information. Most of the time, this kind of dimming is achieved through a DC control command on the ballast of the luminaire (discharge lamp) or through the transformer (halogen lamp). Some manufacturers have adopted a standard analogue 0-10 V dimming protocol that allows ballasts from different manufacturers to be used with compatible systems.

*Step by step dimming* is a way to control the light output of the luminaires based on a limited number of configurations. The rated dimming levels are based on information generated by the controller, received by the actuator and transmitted to the light source. The number of dimming steps is defined by the protocol used. DALI-based dimming system is an example of this kind of step by step dimming (256 dimmed levels). Switching systems perform very well in climates with stable sky conditions, such as south of France, while dimming systems is predisposed to save more energy in climates with variable sky conditions, such as Brussels.

## Wireless sensors and actuators

Wireless sensors (Presence sensor, illuminance sensor, etc.) and actuators (dimmers, switches, etc.) are based on old existing concepts what their intrinsic functionalities concern. It is the way the control is achieved that makes them now attractive: wireless. Their main advantage is their flexibility (no need for cabling). Thus, both installation and operational costs can be reduced significantly. That is why they are used more and more in refurbishing and open space area.

Wireless sensor networks in commercial and industrial buildings are exposed to an increasing number of interference sources, like WiFi nodes, microwaves, Bluetooth devices, RFID, and other wireless sensor networks. Most wireless sensor networks perform well in a *clean* RF environment after initial installation. The challenge is to maintain good performance when there is another deployment of supplementary RF source.

## Others components

The building shell can be integrated in several types of active or passive components that impact directly on heat/cool energy or illuminance level. These components can be placed in roof or in facade. See IEA task 31 and IEA task 21 on daylighting for more details. The visual comfort may be influenced by the daylight availability. We can identify a large list of components influencing the daylighting of the building such as the dynamic glazing systems or the blinds, louvres and shutters family.

### Dynamic glazing systems

Electrochromic, gazochromic and crystal-liquid glazing (EC, GC and CL) are color changing glazing (through voltage control). These windows belong to a new generation of technologies called switchable glazing-or smart windows. Switchable glazing can change the transmittance, transparency, or shading of windows in reaction to an environmental signal such as sunlight, temperature or an electrical control. Smart windows alter from transparent to tint by applying an electrical current. Potential uses for these technologies include daylighting control, glare control, solar heat control, and fading protection in windows and skylights. By automatically controlling the amount of light and solar energy that can pass through the window, smart windows can help save energy.
## Blinds, louvres and shutters family

Generally, louvres and shutters are opaque, rigid, operable blades or panels with manual or automatic controls such as clocks, timers, illuminance sensor or thermostats. Flexible and translucent designs are also available. Louvres reduce heat gain and can transmit, disperse, reflect or reduce daylight. Automatic blinds coupled with blind controllers and combined with lighting control can significantly reduce the need for electric lighting during the day.

## Networks

The evolution of building automation and direct digital control in the 1980's has favoured the development of communication technologies in buildings. Today building automation system offers two main possibilities to integrate the control of different equipment/applications in a building, namely:

a. Proprietary systems

b. Open systems

- Standard system (which comes from a standard)

- De facto standard (which comes from industry best practice)

A proprietary system is a closed system that is developed by a single manufacturer/contractor. The manufacturer holds the knowledge underlying the development of the system. In such systems, the initial costs might be relatively low and easy to set up, but the building owner is locked into products of a single manufacturer and can not take advantage of innovative technologies easily.

An open system is one where standards are developed, published and maintained by an independent recognised organisation body (CEN, ISO, ASHRAE/ANSI, etc.) or an industrial alliance (de facto standard). Any change to the system requires the comments of users, industry, professionals before being approved by the standards / organisation or the alliance. Open communication protocols are now becoming used for the integration of equipment from different manufacturers. This offers the following benefits:

- Media sharing. In this system, different products from different manufacturers run on the same communications cables

- Vendor independence. This applies for initial purchase of different equipment and / or system extension

## Standardization of protocols

The CEN TC247 WG4 has been working on standardisation of data transmission methods between products and systems for HVAC applications. This working group has divided the communication within a building automation system into three types of communication requirements:

- The Management net. It is used for workstation to workstation communication

- The automation or control net. It is used for plant controllers and workstations

- The field net. Used for terminal unit controllers, sensor devices, drives etc.
The work of CEN TC247 is to enhance the implementation of Building Automation System (BAS) by supporting a number of standards. To bring down cost, the standardization work promotes open systems architecture.

Table 6-10 gives a list of communication protocols and the media that are required:

<table><caption>**Table 6-10.** Communication protocols and media. (Adapted from: BCG group - UK)</caption><thead><tr><th>Level</th><th>Protocol</th><th>Transmission Media</th></tr></thead><tbody><tr><td rowspan="2">Management</td><td>BACnet (ISO 14684-5)</td><td>Ethernet, PSTN / dial up modem, IP, MS/TP</td></tr><tr><td>WorldFIP(EN50170)</td><td>Twisted Pair</td></tr><tr><td rowspan="3">Automation</td><td>BACnet (ISO 14684-5)</td><td>Ethernet, LONtalk, PSTN / dial up modem</td></tr><tr><td>KNX (ISO 14543)</td><td>Ethernet</td></tr><tr><td>LONtalk (EN 14908)</td><td>Twisted pair, RF, CPL, IP</td></tr><tr><td rowspan="2">Field</td><td>KNX (ISO 14543)</td><td>Twisted pair, Mains signalling</td></tr><tr><td>LONtalk (EN 14908)</td><td>Twisted pair, RF, CPL, IP</td></tr></tbody></table>

Some commonly used open standards have not been recognised by CEN TC 247, but are in use, for example:

- MODBUS which is often used to attach HVAC plant modules such as a chiller to a BAS.

- IT standards such as Microsoft COM, DCOM or internet standards (TCP/IP, HTTP, etc.) which is used at the management level.

## Proprietary systems and protocols

### ZWAVE (Will become a de facto standard)

<figure><img src="image_97.png" /></figure>

Z-Wave is a new technology in wireless remote control developed by Zensys (http://www.zen-sys.com), from Denmark. Z-Wave is a next-generation wireless ecosystem that lets all home electronics talk to each other, and to the customer, via remote control. It uses simple, reliable, low-power radio waves that easily travel through walls, floors and cabinets. Z-wave uses a sharp Mesh network

topology and has not master node. Therefore, a Z-wave network can span much further than the radio range of a single unit.

### ENOCEAN

<figure><img src="image_98.png" /></figure>

The Enocean company (Enocean 2007) has developed a technology that is based on the efficient exploitation of slightest changes in the environmental energy using the principles of energy harvesting. In order to transform such energy fluctuations into usable electrical energy, electromagnetic, piezogenerators, solar cells, thermocouples, and other energy converters are used.

The products (such as sensors and radio switches) from Enocean are batteryless and were engineered to operate without maintenance. The most pervasive example of a product stemming from the proprietary RF protocol is the battery-free wireless light switch. This product is been marketed with the argument that it requires less time and wire to install because no wire is required between the switch and the light fixture. They also avoid the need to run switched circuits as the actual power switching is performed locally at the load itself. The above list is not exhaustive. In fact there are many others proprietary protocols for Home and building automation (and especially
for lighting) such as system from Creston, Legrand, Wavenis, Lutron, Delta Dore, Schneider electric, Insteon and so on.

## Open systems and protocols (standard system and de facto standard)

### BACnet

BACnet (http://www.bacnet.org/) stands for The Building Automation and Control network. It was developed by ASHRAE and is now published as an ASHRAE/ANSI standard, a CEN standard and an ISO standard. BACnet is a communications protocol for building automation and control networks. It is equally suitable for both the automation and management levels, especially for HVAC, lighting control and fire alarm equipment. It is recognized as an ANSI and CEN standard as well as ISO standard 16484-5. The protocol is based on four layers of the OSI model.

### LonWorks

<figure><img src="image_99.png" /></figure>

LONMARK®

LonWorks (http://www.echelon.com/) was developed by Echelon in the USA. It is a general purpose network using the LonWorks protocol and the Neuron chip. It is most suitable for device-level integration and widely used in buildings on twisted pair cable using a transceiver known as FTT-10. The use of Standard Network Variable Types (SNVTs, pronounced *snivets*) contributes to the interoperability of LonWorks® products from different manufacturers.

## MODBUS (De facto standard)

<figure><img src="image_100.png" /></figure>

MODBUS (http://www.modbus.org) designed by Gould Modicon Company is not an official standard and is supported by most Programmable Logic Controllers (PLC). It relies on a Master/Slave serial protocol. Modbus is considered to be very simple and easy to implement and use, and has been adopted not only by the industrial manufacturing milieu but also by many manufacturers of building equipments Modbus has become extremely popular for the reason that it is free, inexpensive to implement both in hardware and software. It is however limited to simple data exchange and is not used for more sophisticated requirements.

## KONNEX

<figure><img src="image_101.png" /></figure>

Konnex (http://www.knx.org) results from the formal merger of the 3 leading systems for Home and Building automation (BatiBUS, EIB and EHS) into the specification of the new Konnex Association. The common specification of the *KNX* system provides, besides powerful runtime characteristics, an enhanced *toolkit* of services and mechanisms for network management. On the Konnex device network, all the devices come to life to form distributed applications in the true sense of the word. Even on the level of the applications themselves, tight interaction is possible, wherever there is a need or benefit. All march to the beat of powerful interworking models with standardised data-point types and *Functional Block objects*, modelling logical device channels.
## X10 (De facto standard)

<figure><img src="image_102.png" /></figure>

X10 (http://www.x10.com) is an industry standard for communication among devices used for home automation. It primarily uses power line wiring for signalling and control, yet now a radio-based transport is also defined. X10 was developed in 1975 in order to allow remote control of home devices and appliances. It was the first domestic automation technology and remains the most widely available. X10 was the first home automation technology and remains the most widely available. However, now it seems obsolete. Data rates are very low (around 20 bit/s). To summarise, with its tiny command set and poor reliability X10 protocol is simply too limiting for today's home environment control.

## ZIGBEE

<figure><img src="image_103.png" /></figure>

ZigBee

The ZigBee(http://www.zigbee.org) Specification describes the infrastructure and services available to applications operating on the ZigBee platform (ZigBee, 2004). ZigBee is a published specification set of high level communication protocols designed to use small, low power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPANs). ZigBee's current focus is to define a general-purpose, inexpensive self organizing mesh network that can be shared by industrial controls, medical devices, smoke and intruder alarms, building-automation and home automation. The technology is designed to be simpler and cheaper than other WPANs such as Bluetooth. The most capable ZigBee node type is said to require only about 10% of the software of a typical Bluetooth or Wireless Internet node, while the simplest nodes are about 2%. There are currently discussions between the ZigBee commission and BACnet commission to set up a bridge between the *wired* and *wireless* open protocols.

## Communication systems and protocols specific to lighting systems

### DALI

<figure><img src="image_104.png" /></figure>

DALI (DALIa, DALIb) is a digital communication protocol designed specifically for lighting systems. DALI is effective for scene selection and for getting feedback regarding faulty light sources. This makes it very useful to use together with building automation systems where remote supervising and service reports are required. DALI was originally introduced in 1999 by ballast manufacturers who wanted to introduce a standardized digital ballast control protocol. It is designed to be very easy to install and to (re)configure. All actuators, controllers and sensors are connected to one single control cable. A DALI-system consists of load interfaces ( electronic ballasts), control panels ( push buttons), sensors (occupancy sensor) and control interfaces (controller) and gateways ( 1-10V converter). Example of possible DALI operations:

- Individual, group or broadcast messaging

- Request status data from an individual luminaire

- Assigning of addresses to luminaires using a discovering algorithm which makes the need for hard addressing obsolete

- Selection of lighting scenes

It is important to note that DALI is not a new Building Management System (BMS), DALI is only available for lighting. However, it can be an easy add to existing BMS like BACnet, Lonworks or KNX thanks to gateway.
## DMX 512/1990

DMX 512/1990 is a Digital Multiplex Data Transmission standard for Dimmers and Controllers operating in simplex mode (unidirectional). It can control up to 512 channels. Data is transmitted in packets. Each packet updates all the devices installed. Each packet consists of up to 513 frames. After a start frame (consisting of zeros), up to 512 frames can follow containing the data for each device connected. The devices are not directly addressed. The information sent to them is defined by the frame position within the packet.

## Conclusions

The main issue for the success of integrated solutions in buildings is to define the appropriate communication protocol and the media for the information transfer. It is most likely that BACnet, Konnex and LonWorks will be the major actors in this field as there will be integrating HVAC, lighting, fire safety, security functions. However, DALI and wireless low power technologies have a certain future regarding lighting control. On the other hand, DALI has been established worldwide as the standard for digital lighting control. It is an open non-proprietary standard that makes genuine freely addressable lighting control a reality (individual, group, and all together). DALI seems to be much easier to install, extremely versatile and much more cost-effective than any lighting control systems already on the market, despite its greater functionality.

On the other hand, wireless technologies (low consumption or battery less) may present a new solution to bring the installed cost down and to ensure energy efficiency. Over the past 10 years many new RF solutions have been developed into our every-day life. It is expected that soon a reliable, robust, easy-to-install and secure wireless network technology for connecting devices in buildings will gain market acceptance and substantial shares of new and retrofit installations soon. ZigBee and Zwave are heading in this direction. Nevertheless they are still not well defined on a semantic point of view. Moreover it doesn't exist efficient tools to design, install, commission and troubleshoot this kind of technologies.

## Internet Protocols (IP)

IP is said to be among the most important technologies for our industry. IP networks are deployed in the Internet, in extranets, and in intranets. Numerous different media are concerned, for example, fiber optics, cables and wireless. IP is a powerful vehicle for enabling communication but it does not specify the content of messages in such detail that is needed e.g. to make two systems exchange a temperature value.

Today, IP serves as the intermediary network technology. It is principally found in building backbones and access networks to the field-area network. Technologies that provide mechanisms to be transported over IP include LonWorks (EIA-852), BACnet/IP and KNX/IP.
<table><caption>**Table 6-11.** Standard and non standard networks for building automation Communication protocols and media.</caption><thead><tr><th>Network protocol</th><th>Media/Option</th><th>Standard</th><th>Applications for lighting</th><th>Sector of application</th><th>Main Advantages</th></tr></thead><tbody><tr><td>BACnet</td><td>IP, Ethernet, PTP, ZigBee, MS/TP, Lontalk, Arcnet</td><td>Yes ISO 16484-5</td><td>***</td><td>Building automation</td><td>Norm Many networking options</td></tr><tr><td>LonWorks</td><td>IR, PLC, TP, RF, IP</td><td>Yes EN 14908</td><td>***</td><td>Building and home automation</td><td>Norm</td></tr><tr><td>KNX</td><td>IR, PLC, TP, RF, IP</td><td>Yes ISO 14543</td><td>****</td><td>LB and HA</td><td>Norm</td></tr><tr><td>PROFIBUS</td><td>IP, TP</td><td>Not a norm but an industrial standard</td><td>*</td><td>Industrial</td><td>Robustness</td></tr><tr><td>MODBUS</td><td>IP, PTP, MS/TP</td><td>De facto</td><td>**</td><td>Industrial</td><td>Robustness Simplicity</td></tr><tr><td>WorldFIP</td><td>IP, TP</td><td>EN50170</td><td>*</td><td>Industrial</td><td>Robustness</td></tr><tr><td>X10</td><td>PLC, RF</td><td>OPEN not a norm</td><td>***</td><td>HA</td><td>lot of products</td></tr><tr><td>Bluetooth</td><td>RF</td><td>IEEE 802.15.1</td><td>*</td><td>Electronics</td><td>low cost</td></tr><tr><td>ZigBee</td><td>RF</td><td>Base on IEEE 802.15.4</td><td>****</td><td>LB and HA</td><td>low consumption</td></tr><tr><td>DALI</td><td>TP</td><td>IEC 62386</td><td>*****</td><td>Lighting control</td><td>Dedicated to lighting</td></tr><tr><td>DMX</td><td>MS/TP</td><td>YES</td><td>*****</td><td>Theatre lighting</td><td>Dedicated to lighting</td></tr><tr><td>Zwave</td><td>RF</td><td>Not a norm but Industrial standard</td><td>****</td><td>LB and HA</td><td>Low consumption Many application in USA</td></tr><tr><td>INSTEON</td><td>RF, PLC</td><td>Proprietary</td><td>***</td><td>HA</td><td>Robustness Simple to use</td></tr><tr><td>Wavenis</td><td>RF</td><td>Proprietary</td><td>***</td><td>HA</td><td>Simple to use</td></tr><tr><td>IN ONE</td><td>RF, PLC</td><td>Proprietary</td><td>***</td><td>HA</td><td>Simple to use Simple to install</td></tr><tr><td>Enocean</td><td>RF</td><td>Proprietary</td><td>****</td><td>HA</td><td>Battery less Many products</td></tr></tbody></table>

Very few lighting applications : IP: Internet Protocol, RF: Radio Frequency

Few lighting applications : IR: Infra Red, PLC: Power Line Communication

Some lighting applications exists : PTP: Pear to Pear, TP: Twist Pair,

Many lighting applications exists : MS/TP: Master Slave/ Token Passing

Dedicated to lighting : LB: Little Building, HA: Home Automation
## Component analysis

Table 6-12 below gives an overview of the typical use of the different components.

<table><caption>Table 6-12. Components application overview.</caption><thead><tr><th rowspan="2">Components</th><th colspan="3">Simple strategies</th><th colspan="2">Integrated strategies</th></tr><tr><th>Predictable<br>Occupancy<br>Control<br>Strategy</th><th>Real<br>Occupancy<br>Control<br>Strategy</th><th>Constant<br>Illuminance<br>Control<br>Strategy</th><th>Daylight<br>Harvesting<br>Control<br>Strategy</th><th>Integration<br>with blinds</th><th>Integration<br>with HVAC</th></tr></thead><tbody><tr><td colspan="7" style="text-align: center; font-weight: bold;">Sensors</td></tr><tr><td>Scheduler</td><td>✓</td><td></td><td>✓</td><td></td><td>✓</td><td>✓</td></tr><tr><td>Clocks</td><td>✓</td><td></td><td></td><td></td><td>✓</td><td>✓</td></tr><tr><td>Illuminance<br>sensor</td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td></tr><tr><td>Presence<br>sensor</td><td></td><td>✓</td><td></td><td></td><td>✓</td><td>✓</td></tr><tr><td>Temperature<br>sensor</td><td></td><td></td><td></td><td></td><td></td><td>✓</td></tr><tr><td>Wind sensor</td><td></td><td></td><td></td><td></td><td>✓</td><td></td></tr><tr><td colspan="7" style="text-align: center; font-weight: bold;">Actuators</td></tr><tr><td>Switch</td><td>✓</td><td>✓</td><td></td><td>✓</td><td>✓</td><td>✓</td></tr><tr><td>Dimmer</td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td><td>✓</td></tr><tr><td colspan="7" style="text-align: center; font-weight: bold;">Others</td></tr><tr><td>Skywells</td><td></td><td></td><td></td><td>✓</td><td>✓</td><td>✓</td></tr><tr><td>Smart<br>windows</td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td></tr><tr><td>Automatic<br>blinds</td><td></td><td></td><td></td><td></td><td>✓</td><td>✓</td></tr><tr><td colspan="7" style="text-align: center; font-weight: bold;">Networks</td></tr><tr><td>Proprietary</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td></tr><tr><td>Open</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td><td>✓</td></tr></tbody></table>

## 6.5 Recommendations

### General Recommendations

This section suggests a generic analysis scheme to design lighting control systems for new and existing buildings. The *first step* is to collect the building owner needs and the expectation of the different users of the building (facility manager, building operator, occupants). This step is crucial to design a lighting installation as it will:

- enhance the acceptation of the system by the users (expected visual comfort level, adapted human interface, etc.),

- facilitate the overall management of the system by providing relevant information and tools like fault detection, energy monitoring, dashboard etc.

This may be difficult in case of new building especially when the owner is not the end user. The *second step* is to achieve the functional analysis in order to translate the needs into technical terms,
that is, to choose the relevant control strategies, network architectures, systems and equipments. It
includes the definition of a commissioning (Cx) plan corresponding to the above mentioned
functional analysis.

The *third step* is to produce user guides for :

- The building operator to understand the system and optimise its operation (fault detections, maintenance, etc.)

- The facility manager to understand the performance indicators of the dashboard (energy consumption, running cost, pay back time, etc.)

- The occupants to understand the control strategies (predicted occupancy control strategy, real occupancy control strategy, constant illuminance control strategy, daylight harvesting control strategy, etc.) and how to use the control system to optimize his visual comfort with an eco friendly behaviour (e.g. remote control, dimmer, task lighting, etc.)

Specific Recommendation for existing buildings

Installing lighting control system in existing building requires, in addition to the user needs analysis, an audit of the existing lighting installation in order to get a detailed description of the existing strategies, architectures, systems and components.

This audit allows to determine the control potential of the lighting installation (e.g. presence of separated lighting circuit for different zones, presence of electronic ballasts, possibility to install and use a wireless network, electrical network quality, etc.) and to design a relevant system for this building.

For example, wireless networks or power line communication system (PLC) seem very attractive as they are flexible and less expensive to install. However these solutions have limitations when the lighting system is very large (in buildings over 10.000 m²) due to signal attenuation, electromagnetic compatibility disturbance, etc. Figure 6-30 presents a general scheme to design an energy efficient lighting installation with specific consideration for the control system.
<figure><img src="image_105.png" /><figcaption>Figure 6-30. General scheme for energy efficient design of lighting control.</figcaption></figure>
## 6.6 Illustrations

### 6.6.1 Illustration 1: NOSS National Office for Social Security - Belgium

<figure><img src="image_106.png" /><figcaption>Figure 6-31. NOSS building.</figcaption></figure>

This case study is an example of a very simple lighting control system working in a very efficient way. The building is organised in landscape offices (open plan) of about 20 work stations.

**Control and management of the daylight**

There is no advanced daylight control system in the NOSS building. The users have vertical lamellas that they can manually control in order to assume their visual comfort.

<figure><img src="image_107.png" /><figcaption>Figure 6-32. Landscape office at day time.</figcaption></figure>

<figure><img src="image_108.png" /><figcaption>Figure 6-33. Luminaire with daylight sensor.</figcaption></figure>

<figure><img src="image_109.png" /><figcaption>Figure 6-34. Landscape office at night time.</figcaption></figure>

**Control and management of the artificial light**

**Landscape offices**

The artificial lighting is controlled by:

- A manual switch in each local (landscape office) in order to switch lights manually on or off

- Two rows of luminaires (near to the windows and deeper in the local) are connected to a daylight dimming system based on the individual measurement of the luminance of the area under the luminaire.

- A central clock cut the luminaires off at 19:00. A second cut off command is sent at 21:00.

**Circulation areas**

<figure><img src="image_110.png" /><figcaption>Figure 6-35. Circulation area.</figcaption></figure>

The artificial lighting is automatically switched on at 7:00 in all corridors (day time mode). At 19:00, the artificial lighting of the circulation areas is set on night time mode. two luminaires on out of are switched off in order to save energy. But one luminaire out of three stays on for the movement of night workers (for security, cleaning, etc.). A cycle of three days is used to avoid un-uniform ageing of the luminaries. This is done through special cabling so that the luminaire that stays on for the night changes each night.
## Rest rooms

During day time, the artificial lighting of the rest rooms is continuously On. During night time, the artificial lighting of the rest rooms is controlled by a presence PIR sensor with a delay set on 15 minutes.

<table><caption>Table 6-13. NOSS building - lighting control system properties.</caption><thead><tr><th>Features</th><th>System properties</th></tr></thead><tbody><tr><td>Strategy</td><td>Predicted Occupancy Control Strategy<br>Real Occupancy Control Strategy<br>(Time Scheduling Control Strategy)<br>Daylight Harvesting Control Strategy</td></tr><tr><td>Integration level</td><td>Level 2</td></tr><tr><td>Architecture</td><td>Zone Control Architecture</td></tr><tr><td>Network</td><td>Open systems - Standard system</td></tr></tbody></table>

## Building Information

Architect : Régie des Bâtiments

Building owner : Régie des bâtiments (occupant : NOSS)

Location : Place Victor Horta, nr 11, B-1060 Brussels, Belgium

### 6.6.2 Illustration 2: The Berlaymont Building - a louvres façade - Belgium

The concept of Ventilated Double Skin Facades (VDSF) is increasingly often applied in new office buildings or retrofittings. For common VDSF equipped with parallel glazing panes, a link can easily be made between the amount of daylight penetrating the building and the total glazed area of the facade. Louvres facades are a particular concept of Ventilated Double Skin Facades equipped at the outside with inclinable glazed lamellas. They offer a dynamic behaviour, which is function of many elements: slope of the lamellas, climatic conditions (diffuse or direct light), incidence angle of the sun, control algorithm, etc. Such a louvre facade concept has been applied on the Berlaymont building, the new retrofitted building of the European Commission in Brussels (Belgium).

The multi-storey louvre ventilated double skin facade of the Berlaymont presents a cavity that is partitioned neither horizontally nor vertically and therefore forms a single large volume. Metallic floors are installed at each storey in order to allow access for cleaning and maintenance.

<figure><img src="image_111.png" /><figcaption>Figure 6-36. View of the large cavity and the louvres in vertical position.</figcaption></figure>

<figure><img src="image_112.png" /><figcaption>Figure 6-37. Louvres in horizontal position.</figcaption></figure>

<figure><img src="image_113.png" /><figcaption>Figure 6-38. Shadow on the Building – 10 December – 14:00</figcaption></figure>

The difference between this type of facade and the classical multi-storey facade lies in the fact that the outdoor facade is composed exclusively of inclinable louvres.
## Façade description

The Berlaymont building is a louver VDSF building. Its interior skin is composed of traditional double glazing elements. Its external skin is made of a whole of suspended frameworks on which are fixed the glazed plates (200 cm out of 50 cm), with un-uniform thickness (8 mm on the bottom of the facade and 12 mm on the top of the facade) due to their dimensioning with the wind.

<figure><img src="image_114.png" /><figcaption>**Figure 6-39.** Cross-section of a lamella.</figcaption></figure>

<figure><img src="image_115.png" /><figcaption>**Figure 6-40.** View through the louvres.</figcaption></figure>

<figure><img src="image_116.png" /><figcaption>**Figure 6-41.** View of the building.</figcaption></figure>

The glazed lamellas of the exterior skin are made up of two glass leafs which enclose a multi-layer perforated film presenting a white face to the external side to better reflect the light. On the interior side, the louvres present a dark face so as to allow the seeing them. Indeed, the contrast of brightness being positive, view is possible from the inside to the outside but impossible the other way.

## Control and management of the daylight

The slope of the lamellas is ensured by engines, which are ordered from a central processing unit. The control of the slope is done according to various parameters, such as:

- The position of the sun (date and hour)

- The position of the lamellas on the facade (orientation and height)

- The information collected by the outdoor sensors (horizontal illumination, wind speed, rain, outside temperature)

When the outdoor horizontal illuminance is higher than 25000 lx, the lamellas are positioned according to their position on the facade.

<figure><img src="image_117.png" /><figcaption>**Figure 6-42.** Different louvres positions.</figcaption></figure>

If the lamellas are located in a sunny zone (which is function of the date and the lamella's position on the facade), they are tilted so as to be perpendicular to the rays of the sun. Their slope lies thus between 0° and 80°, in order to work as solar protection;

If the plates are located in a shaded zone and if the external horizontal illumination is higher than 25.000 lx, they are placed in position of luminous penetration (slope with 110°), to work as reflectors of light.

When the horizontal outdoor illuminance is lower than 25000 lx, all the lamellas are set in position of luminous penetration (110° of slope) to allow the daylight penetration in the building. Other modes are also integrated into the control algorithm, such as maintenance mode and alarm mode in case of fire.
<figure><img src="image_118.png" /><figcaption>**Figure 6-43.** Louvres in horizontal position – 90° slope.</figcaption></figure>

<figure><img src="image_119.png" /><figcaption>**Figure 6-44.** Louvres in light penetration mode – 110° slope.</figcaption></figure>

The control strategy of the lamella is structured as an open-loop system organized as presented in Figure 6-45.

<figure><img src="image_120.png" /><figcaption>**Figure 6-45.** Structure of the control strategy of the daylighting of the Berlaymont Building.</figcaption></figure>
## Control and management of the artificial light

The control of the artificial light in the individual offices of the Berlaymont Building is a function of:

- An individual switch. An individual switch controls the luminaires for each local (Manual On and Manual Off)

- The absence detection. If there is nobody in a local (office), the light switch off after a delay (than can be adjusted)

- The daylighting level. The illuminance level of the artificial lighting is automatically set to 300 lx or 500 lx in the local (office) in function of the outdoor illuminance level (daylighting level). This control of the artificial lighting is function of general settings for each wing the building.

<table><caption>Table 6-14. Berlaymont building - lighting control system properties.</caption><thead><tr><td>Features</td><td>System properties</td></tr></thead><tbody><tr><td>Strategy</td><td>Constant Illuminance Control Strategy<br/>Daylight Harvesting Control Strategy</td></tr><tr><td>Integration level</td><td>Level 3</td></tr><tr><td>Architecture</td><td>Plant Control Architecture</td></tr><tr><td>Network</td><td>Open systems - Standard system</td></tr></tbody></table>

## Building Information

Architect: P. Lallemand, S. Beckers, Berlaymont 2000

Building tenant : European Commission

Location : Rue de la loi, nr 200, B-1000 Brussels, Belgium.

### 6.6.3 Illustration 3: Intecom project - France

The aim of the Intecom project was to develop smart systems to integrate the lighting control, blinds and HVAC applications to improve the indoor environment and reduce energy consumption. A good integration can be achieved through a limited data exchange. CSTB has focused on the interactions at the zone level among the three applications: HVAC, lighting and blinds. At the zone level, the different applications enable to reach the following goals during occupied period:

- Provide desired thermal comfort

- Provide desired illuminance level

- Avoid glare or provide requested contrast level

When the space is unoccupied, only the energy economy target needs to be met. The control strategies has been first assessed by simulation using the SIMBAD Building HVAC toolbox. The implementation has been carried out using the general-purpose simulation tool (MATLAB/Simulink/Stateflow). Two emulators have been developed, namely; a zone emulator and a building emulator. The communication between building and prototypes was supported by the Lonworks standard protocol.

<figure><img src="image_121.png" /><figcaption>Figure 6-46. One zone sample.</figcaption></figure>

The zone emulator consists of a single room with a fan coil unit, a luminaire with electronic ballast and a screen blind.
<figure><img src="image_122.png" /></figure>

The building emulator consists of a six-zones building with a VAV system for air conditioning and the same characteristics as the zone emulator for the light and blind equipments.

<caption>**Figure 6-47.** *Six zones sample.*</caption>

The following facts can be considered on the communication among the controllers:

- The blind can answer to a request of the artificial light or HVAC system.

- The light controller can request blind for more daylight.

- The HVAC controller can request the blind to reduce solar gains or ask the light to switch on to bring more internal gains.

- The interactions among the applications will depend on the amount and type of data that is exchanged.

<figure><img src="image_123.png" /><figcaption>**Figure 6-48.** *Communication between goal oriented and equipment oriented controllers.*</figcaption></figure>

The simulation studies have shown that:

- There is significant potential for energy savings and visual comfort with integrated control of light and blinds only if the lighting system possesses a dimming actuator.

- The integration of HVAC and blinds applications does not gain any major advantages.

- The integration of HVAC, light and blinds applications can bring up to 50% of energy savings during summer periods.

- In the case of integration of HVAC, light and blinds, there is a tendency of an increased number of blind movements during summer. This is usually not accepted by occupant.
<table><caption>**Table 6-15.** Intercom project - lighting control system properties.</caption><thead><tr><th>Features</th><th>System properties</th></tr></thead><tbody><tr><td>Strategy</td><td>Real Occupancy Control Strategy<br>Constant Illuminance Control Strategy<br>Daylight Harvesting Control Strategy</td></tr><tr><td>Integration level</td><td>Level 3</td></tr><tr><td>Architecture</td><td>Plant Control Architecture</td></tr><tr><td>Network</td><td>Proprietary system</td></tr></tbody></table>

### 6.6.4 Illustration 3: DAMEX project - Finland

The objective was to improve energy efficiency of an office building by maximizing daylight utilization. This was achieved by means of the integrated control system consisting of illuminance sensors, venetian blinds and electric lights, all interfaced to the DALI bus (Figure 6-49).

Short description of the characteristic features of the system:

- Both blinds and lights were controlled using only a vertical outdoor illuminance sensor without any indoor light sensors.

- According to measured vertical façade illuminance, and current date and time, the control system selects a predetermined lighting scene to be used. The scenes stored in the system memory contain all the information which is needed to control the devices.

- Only a little instrumentation is needed. The principle was to apply the daylight measurements and computer simulations in modelling the lighting process and then utilize the model in control.

- Individual light output levels for each luminaire or lamp and blind position were created and stored using DALI programming software. The predetermined scenes were created using real daylight measurements and lighting software. The DALI system is capable of storing 16 different scenes.

The measurements gave important information how indoor lighting and window luminances are changing in different daylight situations. Predetermined scenes were selected to minimize the glare, not to maximize the indoor light levels. The blind angles were selected to keep the luminance of the window within an acceptable range. Delays in control are short enough to prevent intolerable glare in dynamic daylight situations with high sun intensity.

Results showed that the described system can be effectively used to utilize the daylight in office building without causing glare to the users. The glare caused by the daylight reduces often the savings otherwise achievable through daylight.

An example of the results is shown in Figure 6-50 were the data is measured on 21st of December, i.e., the shortest day of the year. Due to the glare the blinds shut at 10:51 AM when vertical illuminance exceeded 16000 lx, and opened again at 14:28 PM when the vertical illuminance falls
under 12000 lx. The figure presents the vertical illuminance (highest curve), indoor sensor data of the horizontal illuminance (middle curves) and the blinds (lower curve).

The relative power of the lighting during one day is shown in Figure 6-51. The minimum power at noon was 43% and the average power 73% of the night-time value. The main conclusion is that even in December it is possible to achieve energy savings in the Finnish climate. In summertime when days are longer, the savings are remarkable, because with an optimal blind control the need of electric light is minimal during normal working hours.

<figure><img src="image_124.png" /><figcaption>**Figure 6-49.** The integrated control system interfaced to DALI bus.</figcaption></figure>

<figure><img src="image_125.png" /><figcaption>**Figure 6-50.** Illustration of the sensor data and operation of the blinds during one day.</figcaption></figure>
<figure><img src="image_126.png" /><figcaption>**Figure 6-51.** Electric power reductions during the day of Figure 6-50.</figcaption></figure>

## 6.7 Conclusions

Lighting is an important part of the global building energy consumption. It can represent about 5 to 10 kWh/m² year in the residential sector and reach to more than 60 kWh/m² year in tertiary sector. Lighting consumption can be easily reduced with efficient light sources. Further energy gains can be achieved with smart lighting control strategies. Today, the most common form of control (the standard wall switch) is being replaced by automatic systems which are based on occupancy or daylight harvesting. Most common examples are occupancy sensors which turn the lights off when the area is unoccupied, time-based controls and the dimmer plus photocell combination. All are more effective than the standard switches in saving energy. Potential gains vary from 10% with simple clock to more than 60% with a total integrated solution (occupancy plus daylight plus HVAC). However, each sensor can turn the lights off by mistake if they are not well specified, installed and maintained. On the other hand, if they operate well they provide a direct benefit to the occupant in terms of energy saving, comfort and ease of use, in new building as well as in refurbishment.

Furthermore, today new components are coming on the market like smart windows and intelligent automatic blinds. The last component allows obtaining significant energy savings. However, no concrete study can actually show this. Finally, lighting management/control systems can easily be associated with BMS. Smart integration with other technical equipments (such as Blinds and HVAC) can be done to decrease energy consumption and improve general comfort. Such solution can allow building operator to provide the *right amount of light where and when it is needed*. On the other hand, it increases the complexity of the lighting system so that commissioning becomes essential for a good integration.

Lighting automation systems must be calibrated when installed, if possible after the building is occupied and the facility staff has to be involved in the commissioning process. The building sector is rife with anecdotes on lighting control systems which do not run as expected or do not work at all because they were improperly installed or because the facility managers or occupants do not understand them. The commissioning process will reduce these problems.
References

EC (European Commission) 2007. Available from:

http://www.ec.europa.eu/comm/energy_transport/atlas/html/buildings.html

Floyd, D.B., Parker, D., 1995. Field Commissioning of a daylight-dimming lighting system. In Proceedings of Right Light Three, 3rd European Conference on Energy Efficient Lighting, Newcastle, UK, pp. 83–88

IEA 2001. IEA Task 31 - Daylighting Buildings in the 21st Century, website http://www.iea-shc.org/task31/

IEA 2006. International Energy Agency. Light's Labour's Lost. IEA Publications, France.

Maniccia D, Rutledge B, Rea MS, Morrow W. 1999. Occupant control of manual lighting controls in private offices. Journal of the IES, 28(2):42-56.

Maniccia, Dorene and Allan Tweed 2000. Occupancy sensor simulations and energy analysis for commercial buildings. Troy, NY: Lighting Research Center, Rensselaer Polytechnic Institute.

NBI 2003. Advanced Lighting Guidelines, New Building Institute Inc., 2003.

Rundquist, R. A., McDougall, T. G., and Benya, J. R. (1996). Lighting controls: Patterns for design. (TR 107230) Pleasant Hills, CA: Electric Power Research Institute.
# Chapter 7: Life cycle analysis and life cycle costs

## Topics covered

<table><tr><td>7</td><td>Life cycle analysis and life cycle costs</td><td>185</td></tr><tr><td>7.1</td><td>Life cycle analysis</td><td>185</td></tr><tr><td>7.2</td><td>Calculation of lighting energy</td><td>187</td></tr><tr><td></td><td>Normalized power density</td><td>189</td></tr><tr><td>7.3</td><td>Economic evaluation of lighting</td><td>190</td></tr><tr><td></td><td>Costs</td><td>190</td></tr><tr><td></td><td>Example of the use of equations</td><td>192</td></tr><tr><td></td><td>Other considerations</td><td>194</td></tr><tr><td></td><td>Maintenance</td><td>194</td></tr><tr><td>7.4</td><td>Examples of life cycle costs</td><td>195</td></tr><tr><td>7.5</td><td>Long term assessment of costs associated with lighting and daylighting techniques</td><td>199</td></tr><tr><td></td><td>References</td><td>200</td></tr></table>
# 7 Life cycle analysis and life cycle costs

## 7.1 Life cycle analysis

Life cycle analysis (LCA) gives an overview of the energy and raw materials use of a product from cradle to grave. It considers also how much solid, liquid and gaseous waste and emissions are generated in each stage of the product's life. (GDRC 2009)

<figure><img src="image_127.png" /><figcaption>Figure 7-1. A principle schematic of a life cycle analysis.</figcaption></figure>

The scope definition is very crucial in LCA. It defines what is included in the analysis. For example are transports or mining of the raw materials included, does the analysis concentrate on a specific life cycle phase, or is the whole life cycle considered. The energy resources used in the operation phase is very important to be defined. Usually, the energy use in operation phase causes the largest environmental impacts of the whole life cycle, especially when it comes to energy-using products, such as lighting equipment.

The LCA is a useful tool in environmentally conscious product design. The results of the LCA can be used to compare products or technologies, and the results indicate on what to concentrate in ecodesign. The results of an LCA are often given as environmental impact categories or as the so called single scale indices. Environmental impact categories are for example primary energy, toxicological impacts, global warming potential and acidification potential. These allow the comparison from the point of view of a single type of environmental impact. Single scale indices weigh different environmental impacts and calculate them into one score to describe the total environmental performance of a product. This makes the comparison of the total environmental impact of products easier. Single scale indices are for example Ecoindicator'99 and CML2001. The Ecoindicator'99 concentrates on respiratory effects and climate change, whereas the CML2001 emphasizes global warming and acidification. (Eco-Indicator 2009) (CML 2001)

In the following examples the environmental effects of different lamp types are compared on a general level. The comparison is made regarding their energy consumption, not in environmental impact categories of single scale indices. This makes the analysis very simple and the comparison easy.
In an early study by Gydesen and Maimann (1991), the energy consumption of a 15 W CFL and a 60 W incandescent lamp is compared for the production, operation and disposal phases. The lifetimes were 8000 h for CFL and 1000 h for incandescent lamp, respectively. The energy used was also calculated against the light service the lamps provide in lumen hours. The results showed that CFL consumes 17 kWh/Mlmh and incandescent lamp 82 kWh/Mlmh.

<table><caption>**Table 7-1.** Energy consumption and emissions during life cycle of CFL and incandescent lamp. (Gydesen and Maimann 1991)</caption><thead><tr><th></th><th>15 W CFL</th><th>60 W GLS</th></tr></thead><tbody><tr><th colspan="3" style="text-align: left;">Energy consumption & quantity of light</th></tr><tr><th scope="row">Production</th><td>1.4 kWh</td><td>0.15 kWh</td></tr><tr><th scope="row">Use</th><td>120 kWh</td><td>60 kWh</td></tr><tr><th scope="row">Disposal</th><td colspan="2">0 kWh</td></tr><tr><th scope="row">Total</th><td>121 kWh</td><td>60 kWh</td></tr><tr><th scope="row">Service</th><td>7.2 Mlmh</td><td>0.73 Mlmh</td></tr><tr><th colspan="3" style="text-align: left;">Energy consumption per Mlmh</th></tr><tr><th scope="row">Production</th><td>0.19 kWh</td><td>0.21 kWh</td></tr><tr><th scope="row">Use</th><td>17 kWh</td><td>82 kWh</td></tr><tr><th scope="row">Disposal</th><td>0 kWh</td><td>0 kWh</td></tr><tr><th scope="row">Total</th><td>17 kWh</td><td>82 kWh</td></tr></tbody></table><table><thead><tr><th></th><th>15 W CFL</th><th>60 W GLS</th></tr></thead><tbody><tr><th colspan="3" style="text-align: left;">Production and use</th></tr><tr><th scope="row">CO<sub>2</sub></th><td>14.4 kg</td><td>70.0 kg</td></tr><tr><th scope="row">SO<sub>2</sub></th><td>0.11 kg</td><td>0.53 kg</td></tr><tr><th scope="row">NO<sub>x</sub></th><td>0.07 kg</td><td>0.35 kg</td></tr><tr><th scope="row">CH<sub>4</sub></th><td>0.05 g</td><td>0.25 g</td></tr><tr><th scope="row">fly ash</th><td>0.82 kg</td><td>4.00 kg</td></tr><tr><th scope="row">mercury</th><td>1.00 mg</td><td>4.86 mg</td></tr><tr><th scope="row">gaseous/solid split</th><td>0.40/0.60</td><td>1.94/2.92</td></tr><tr><th colspan="3" style="text-align: left;">Disposal</th></tr><tr><th scope="row">mercury</th><td>0.69 mg</td><td></td></tr><tr><th scope="row">solid waste</th><td>0.015 kg</td><td>0.042 kg</td></tr><tr><th scope="row">Total mercury</th><td>1.69 mg</td><td>4.86 mg</td></tr><tr><th scope="row">Total solid waste</th><td>0.83 kg</td><td>4.04 kg</td></tr></tbody></table>

The mercury content in operation was achieved by assuming that the electricity is produced with coal power plant. The amount of mercury and other emissions from electricity generation depend on the electricity generation system that differs country by country.

The European Lamp Companies Federation has published environmental impact assessment of lamps on their webpage. According to that 90% of the energy is consumed during the operation phase. In other phases, energy is consumed as follows: resource 4%, production 5% and transport 3%, and disposal releases 2% (ELC 2009).

<figure><img src="image_128.png" /><figcaption>**Figure 7-2.** Lamp energy consumption during life cycle according to European Lamp Companies Federation (ELC 2009).</figcaption></figure>

Preliminary data of Osram on LEDs life cycle assessment show that only 2% of total energy consumed by LED based lamps is used in their production. (LEDs Magazine 2009)
In the life cycle analysis of light sources the environmental impacts are assessed in raw material production, manufacturing, distribution, use / consumption and disposal through fifteen environmental indicators. One of the indicators is the Global Warming Potential (GWP), which is measured in kilograms of carbon dioxide (CO₂) equivalents. In the use phase the GWP indicator is measured by the power consumption. In the following the percentage is the GWP impact of the use calculated over the total GWP impact for different light source systems. (DEFRA 2009).

- integrally ballasted LED lamp, 93.3%

— dedicated LED luminaire system, 97.3%

— ceramic metal halide luminaire system, 98.7%

— T5 luminaire system, 97.7%

— integrally ballasted compact fluorescent lamp, 97.7%

— general service incandescent lamp, 99.7%.

7.2 Calculation of lighting energy

The total lighting energy used by a lighting system depends, in addition to the used equipment (lamps, ballasts and luminaires), on the lighting design and the room itself. The efficiency of the lamps can be defined as luminous efficacy (lm/W). The ballast losses define the efficiency of the ballast and luminaire output ratio (LOR) defines the efficiency of the luminaire. The lighting design has an effect on the position of the luminaires (related e.g. to working desk), the illuminance, illuminance distribution and maintenance. Also the room has an effect on the illuminance, since part of the light comes to the working desk through reflections. An extreme example of this is indirect lighting in which all the light is reflected through ceiling and walls to horizontal surfaces. The shape of the room, height (luminaire distance from horizontal plane) and the surface reflectances (related to colors) together with the luminous distribution of the luminaire affect the illuminance and illuminance distribution in the room.

<figure><img src="image_129.png" /><figcaption>**Figure 7-3.** *Factors affecting the total energy usage of lighting.*</figcaption></figure>

Figure 7-3 shows the factors affecting the total lighting energy consumption in a room. The efficiency of the luminaire (light output ratio) is represented by the symbol *LOR*. The utilance *U* describes the amount of luminous flux reaching the task area divided by the luminous flux of the luminaires. The utilance is affected by the luminous intensity distribution of the luminaire, reflectances of the room surfaces ($\rho_c, \rho_w, \rho_f$), width (*w*) and length (*l*) of the room and the distance between the workplane and the luminaires (*h*<sub>m</sub>). The lumen maintenance factor (MF) includes the lumen depreciation of the lamps and the depreciation caused by contamination of luminaire and the room surfaces. The energy consumption can be reduced by dimming the lights according to daylight (*f*<sub>d</sub>). Lights can be controlled also by an occupancy sensor (*f*<sub>o</sub>), a switch (*f*<sub>s</sub>) or a dimmer (*f*<sub>c</sub>) in the room.

Reducing the installed power of a lighting system represents only one part of the lighting energy saving opportunity. Lighting energy consumption can also be decreased by reducing the use of power by using lighting control systems. This can be done by the application of occupancy sensors,
and automatic switching and dimming according to the availability of daylight. The total energy consumption can be calculated, if the total installed power is known.

$$W = \sum Ptf \qquad (7-1)$$

where

* W energy consumption, kWh

* P installed power, W

* t annual burning hours, h

* f control factor, which takes into account both the dimming and switch off periods.

The average illuminance is luminous flux per illuminated area. Part of the luminous flux of the lamps is blocked by the luminaire while part of the luminous flux reaching the task area is reflected from the room surfaces.

The average illuminance of the room is

$$E = MF \cdot \eta \frac{N\Phi}{A} \qquad (7-2)$$

where

* E average illuminance, lx

* MF maintenance factor (product of lamp lumen depreciation and contamination of the luminaire and room surfaces)

* η utilization factor (product of luminaire light output ratio and utilance of the room).

* N number of the luminaires

* Φ luminous flux of the lamps in one luminaire, lm

* A area of the room, m²

The total luminous flux of the luminaires ($N\Phi$) is the product of system luminous efficacy ($\eta_\Phi$) and installed power ($P$) i.e. $N\Phi = \eta_\Phi P$. Inserting this in Equation (7-2) leads to:

$$P_A = \frac{P}{A} = \frac{E}{MF \cdot \eta \eta_\Phi} \qquad (7-3)$$

where

* $P_A$ lighting power density in a room, W/m²

* $\eta_\Phi$ system luminous efficacy (lamp luminous efficacy including ballast losses), lm/W

Equation (7-3) is used to calculate power densities as a function of light source luminous efficacy in Figure 7-4. With T5 lamps the luminous efficacy of the system is 90 lm/W and 500 lx can be reached with installed power density of 15 W/m². With CFLs the power density would be about 27 W/m².
<figure><img src="image_130.png" /><figcaption>**Figure 7-4.** Power density (W/m²) as a function of light source luminous efficacy (lm/W) at different illuminance levels (lx), maintenance factor MF = 0.75 and utilization factor η = 0.5.</figcaption></figure>

Figure 7-5 shows the effects of maintenance factor *MF* and utilization factor *η* on power density. In the calculations illuminance has been 500 lx and lamp luminous efficacy 80 lm/W. It is possible to achieve the desired illuminance level of 500 lx with power densities of less than 10 W/m², when the maintenance factor is higher than 0.90 and the utilization factor is higher than 0.80.

<figure><img src="image_131.png" /><figcaption>**Figure 7-5.** Power density (W/m²) as a function of utilization factor at different maintenance factor values (MF = 0.50, 0.75, 0.90), calculated for illuminance *E* = 500 lx and system luminous efficacy *η*φ = 80 lm/W.</figcaption></figure>

**Normalized power density**

Hanselaer *et al.* (2007) defined the normalized power density NPD by dividing the installed power by the maintained luminous flux on the task area (in units of 100 lm or 100 lx, m⁻²) as:
$$NPD = \frac{P_{sys}}{\Phi_{TA}^{fin}} [W/m^2 \cdot 100lx] = \frac{100}{MF \cdot U \cdot LOR \cdot \eta_{lamp} \cdot \eta_{gear}} \quad (7-4)$$

Where

* NPD normalised power density, W/(m², 100 lx)

* Psys total system power, lamps, ballasts, etc., W

* ΦfinTA maintained luminous flux on the task area, lm

* MF maintenance factor, ratio of the average illuminance on the working plane after a certain period of use of lighting installation to the initial average illuminance

* U utilance, relates the luminous flux from the luminaires to the luminous flux on the target area

* LOR Light Output Ratio or the efficiency of the luminaire

* ηlamp initial luminous efficacy of the lamp, lm/W

* ηgear efficiency of the control gear

According to Hanselaer et al. (2007) the target values for efficient lighting installations are ηgear > 0.84, ηlamp > 70 lm/W, LOR > 0.75, MF > 0.75, U > 2/(1+0.5(AnTA/ATA)). AnTA is the task area and AnTA the total non-task area. In defining the utilance, it is supposed that the mean initial illuminance on the non-task area is lower than the initial illuminance on the task area.

## 7.3 Economic evaluation of lighting

For economic evaluation of different lighting solutions, a life cycle cost analysis has to be made. This means, that all cost categories including initial and variable costs must be considered over the lifetime of the whole lighting installation. Initial costs are e.g. costs for the lighting design, lighting equipment, wiring and control devices, and the labour for the installation of the system. Variable costs may include replacement of the burnt out lamps (relamping), cleaning, energy, replacement of other parts (reflectors, lenses, louvers, ballasts, etc.) or any other costs that will be incurred.

Usually, only the installation costs are taken into account. People are not aware of the variable costs. In commercial buildings the variable costs are often paid by others who rent the apartment, and the initial costs are usually paid by the investor who makes the system decisions. The energy costs of a lighting installation during the whole life cycle are often the largest part of the whole costs.

### Costs

#### Initial costs

The initial costs are the investment costs, which can be converted to annual costs by multiplying them by the capital recovery factor.

$$C_I = I \times \frac{i(1+i)^n}{(1+i)^n - 1} \quad (7-5)$$

where

* C<sub>I</sub> annual costs of the initial investment, €

* I investment cost (initial costs of equipment, design, installation, etc.), €

* i interest rate (i = p/100, where p is interest rate in percentage)

* n number of years (service life of lighting installation).
## Variable costs

The variable costs consist of maintenance costs and service costs. The maintenance costs include energy costs and lamp replacement costs. The service costs can include, for instance, the costs of cleaning and reparation of luminaires.

### Energy costs $C_e$

Energy costs are calculated by multiplying the total power of the lighting installation by annual burning hours and the price of electricity.

$$C_e = n_{lu} c_e t P10^{-5} \qquad (7-6)$$

where

$C_e$ energy costs, €

$n_{lu}$ number of the luminaires

$c_e$ price of electricity c/kWh

$t$ annual burning hours, h

$P$ power of the luminaire, lamp and ballast, W.

### Lamp costs $C_L$

The annual lamp costs are calculated by multiplying the lamp price by the quotient of the annual burning hours and lamp life ($t/t_{LL}$). Instead of the quotient also the capital recovery factor can be used. This is reasonable if $t/t_{LL}$ is small, i.e. either the burning hours are small or the lamp life is long.

$$C_L = n_L c_L (t/t_{LL})(1+k) \qquad (7-7)$$

where

$C_L$ annual lamp costs including the lamps for spot relamping, €

$n_L$ number of the lamps

$c_L$ price of a lamp, €

$t$ burning hours, h

$t_{LL}$ lamp life, h

$k$ average mortality during lamp group replacement period, %.

### Group replacement costs $C_G$

If lamps are changed by group replacement, the replacement period can be chosen based for example on 30% decrease of illuminance due to lumen depreciation and lamp mortality. Fluorescent lamps contain mercury and therefore the replacement costs have to include also the disposal of the old lamps.

$$C_G = n_L c_G / T \qquad (7-8)$$

where

$C_G$ annual group replacement cost, €

$n_L$ number of the lamps

$c_G$ group replacement costs per lamp in group replacement including lamp disposal, €

$T$ group replacement period in years, a.
Spot replacement costs $C_s$

$$C_s = n_L c_s k / T \qquad (7-9)$$

where

$C_s$ annual spot replacement costs, €

$n_L$ number of the lamps

$c_s$ spot replacement costs per lamp in spot replacement including lamp disposal, €

$k$ average mortality during lamp group replacement period, %

$T$ group replacement period in years, a

Service cost

Service costs result from the cleaning and reparation of luminaires and in dirty conditions also from the cleaning and/or painting of room surfaces. Service costs are very dependent on the circumstances. If the lamps and luminaires are cleaned on a regular basis, for instance combined with the group replacement, then the annual cleaning costs can be calculated by dividing the work and material costs by the cleaning period.

$$C_c = n_L (c_c + c_m) / t_c \qquad (7-10)$$

where

$C_c$ annual cleaning costs, €

$n_L$ number of the lamps

$c_c$ work costs of cleaning per lamp, €

$c_m$ material costs of cleaning per lamp, €

$t_c$ cleaning period in years, a.

### Example of the use of equations

In the following the energy costs $C_e$ and lamp costs $C_L$ using different lamps are calculated. The lamps are incandescent (Inc.), compact fluorescent (CFL) and LED lamps. Since the price of the lamps is quite different, the lamp costs have been calculated by using the capital recovery factor, Equation (7-5). The service life (number of years $n$) is one year for incandescent, three years for CFL1 and five years for CFL2, LED1 and LED2 lamps. The actual service life of, for example, LED2 is much longer than five years, taking the annual burning hours of 2000 h and lamp life of 50 000 hours. The service life of LED2 would be 25 years and the initial costs only 3.55 €. However, due to service life of five years used in the calculations, the initial costs for LED2 are 11.55 €. Table 7-2 shows the initial values used for calculations. With incandescent lamp, another lamp costs of 1.05 € has been added after 1500 hours, 2500 hours and again after 3500 burning hours.
<table><caption>**Table 7-2.** Initial values for calculation of energy costs and lamp costs and the results of the calculations for different lamp types.</caption><thead><tr><th>Initial Values</th><th>GLS</th><th>CFL1</th><th>CFL2</th><th>LED1</th><th>LED2</th></tr></thead><tbody><tr><td>c<sub>e</sub> price of the electricity, c/kWh</td><td>15</td><td>15</td><td>15</td><td>15</td><td>15</td></tr><tr><td>P power of the lamp, W</td><td>60</td><td>15</td><td>15</td><td>15</td><td>10</td></tr><tr><td>c<sub>L</sub> price of the lamp, €</td><td>0.5</td><td>5</td><td>10</td><td>20</td><td>50</td></tr><tr><td>t<sub>LL</sub> lamp life, h</td><td>1000</td><td>6000</td><td>12000</td><td>20000</td><td>50000</td></tr><tr><td>t annual burning hours</td><td>2000</td><td>2000</td><td>2000</td><td>2000</td><td>2000</td></tr><tr><td>k mortality, %</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>i interest rate</td><td>0.05</td><td>0.05</td><td>0.05</td><td>0.05</td><td>0.05</td></tr><tr><td>n service life (number of years)</td><td>1</td><td>3</td><td>5</td><td>5</td><td>5</td></tr><tr><td colspan="6">Calculated values</td></tr><tr><td>C<sub>I</sub> Initial costs, €</td><td>0.53</td><td>1.84</td><td>2.31</td><td>4.62</td><td>11.55</td></tr><tr><td>C<sub>e</sub> Energy costs, €</td><td>18.00</td><td>4.5</td><td>4.5</td><td>4.5</td><td>3.00</td></tr><tr><td>C<sub>L</sub> Lamp costs, €</td><td>1.05</td><td>1.84</td><td>2.31</td><td>4.62</td><td>11.55</td></tr></tbody></table>

Figure 7-6 shows the effect of annual burning hours on the lamp and energy costs. When using the service lives of 3 years and 5 years, the total costs for CFL1 are 4 € and for CFL2 4.50 €, and for incandescent lamp 9.50 € with 1000 annual burning hours.

<figure><img src="image_132.png" /><figcaption>**Figure 7-6.** Combined lamp and energy costs as a function of annual burning hours for different lamp types.</figcaption></figure>

Figure 7-7 shows the distribution of lamp costs and energy costs with 2000 burning hours. In case of the incandescent lamp, two lamps are used during this period. With LED1 annual energy costs and lamp costs are almost equal, 4.50 € and 4.62 €. The price of the LED1 lamp is 20 € and the service life is five years. The price of electricity is 15 c/kWh and the power of the lamp is 15 W. With CFL and Incandescent lamps the energy costs are dominating.
<figure><img src="image_133.png" /><figcaption>**Figure 7-7.** Lamp and energy costs of different lamp types with 2000 annual burning hours.</figcaption></figure>

## Other considerations

- The electric energy for lighting is an internal heat gain in a room. In winter peaking regions (cold areas) it can be utilized for heating, but in other regions and in summer time it will increase the need for cooling energy.

- If the lighting is dimmed, for instance according to daylight, this will decrease the energy consumption. With fluorescent lamps even if the luminous flux is on the minimum level (1% to 5%) the system energy consumption is still about 20%.

- Lighting control strategies can help to save energy. If fluorescent lamps are switched off regularly, this will save energy, but it will shorten the lamp life and thus increase the lamp and replacement costs. Calculations show that generally it is economical to switch off fluorescent lamps when the switch off time is 15 minutes or longer.

## Maintenance

All system components age by time and must be replaced at certain periods (before dropping out). Lamp performance decreases over time before failure (Figure 7-8), and dirt accumulations on luminaires and room surfaces decreases the utilization factors. The lack of maintenance has a negative effect on visual perception, task performance, safety and security, and it wastes energy as well. Both aging and dirt accumulation can reduce the efficiency of a whole lighting installation by 50% or even more, depending on the application and equipment used. The following measures should be defined by a regular maintenance schedule:

- Cleaning of luminaires, daylighting devices and rooms (dirt depreciation)

- Replacement of burned out lamps

- Replacement of other parts (e.g. corroded reflectors)

- Renovation and retrofitting of antiquated systems and components.
<figure><img src="image_134.png" /><figcaption>Figure 7-8. Lamp luminous flux depreciation during life time (principal sketch).</figcaption></figure>

## 7.4 Examples of life cycle costs

A simple appraisal with very common parameters (assumptions) for two lighting examples (shop lighting and office lighting) shows the LCC dimensions.

The following terminologies are used in the examples:

* **E** average illuminance, lx

* **MF** maintenance factor, including lamp lumen depreciation and dirt accumulation on luminaires and on room surfaces

* **η** utilization factor (product of luminaire light output ratio and utilance of the room)

* **Φ** luminous flux of the lamps in one luminaire, lm

* **A** area of the room, m²

* **W** energy consumption, kWh

* **P** installed power, W

* **t** annual burning hours, h

### Shop lighting

Required illuminance

Dimensions

η

MF

t

lamp type

power (per luminaire)

E= 1000 lx

A = 4m x 5m = 20 m²

0,6

0.67 (acc. to DIN12464)

3000 h

HCI-T 35W → 3500 lm

40 W → 87.5 lm/W

<figure><img src="image_135.png" /></figure>
## Simple calculation without maintenance and relamping costs

$$ \Phi = E \cdot A / (\eta \cdot MF) = 49.8 \text{ klm} $$

$$ \text{for } t=3000 \text{ h} \rightarrow 149 \text{ Mlmh} $$

$$ P = 49.8 \text{ klm} / 87.5 \text{ lm/W} = 569 \text{ W} \rightarrow 28 \text{ W/m}^2 $$

$$ \text{for } t=3000 \text{ h} \rightarrow W = 1700 \text{ kWh} \rightarrow 85 \text{ kWh/m}^2, \text{a} $$

Installation costs 100 €/m²

Energy consumption 85 kWh/m², a

Costs for electricity (0.15€/kWh price) 12.75 €/m², a

Costs for electricity for 10 years 127 €/m²

## Present value of a growing annuity

Present value of an annuity is a series of equal payments or receipts that occur at evenly spaced intervals that occur at the end of each period. In the present value of a growing annuity (PVGA) there is a rate of growth of the annuity. Annuity is the payment in the first period.

$$ PV(a) = \frac{a}{i-g} \left[ 1 - \left( \frac{1+g}{1+i} \right)^{n_p} \right] $$

where

PV(a) value of the annuity at time = 0

a value of the individual payments in each compounding period

i interest rate that would be compounded for each period of time

$n_p$ number of payment periods

g increase in payments, each payment grows by a factor of (1+g).

We can consider the previous example of shop lighting with the following assumptions.

Total life cycle 24 years

Maintenance interval 3 years ($n_p = 8$)

(cleaning and relamping)

Maintenance costs 22 €/m²

Interest rate 6%

Electricity cost 12.75 €/m² year ($n_p = 24$)

Electricity price increase 1% / 5%

Present values of the total life cycle costs are

Installation 100 €/m²

Electricity 175 €/m² (1% annual increase)

Electricity 259 €/m² (5% annual increase)

Maintenance 137 €/m² (no annual increase)

Figure 7-9 shows the share of energy costs in the life cycle costs. The calculation is done over 24 years. Figure shows two examples of the increase of the prices one with 1% annual increase in the electricity price and the other with 5% annual increase in the electricity price.
<figure><img src="image_136.png" /><figcaption>**Figure 7-9.** Distribution of costs [€/m²] for shop lighting during life cycle of an installation (24 years). Increase of 1% (left) or 5% (right) of the price of electricity has been considered.</figcaption></figure>

## Office-lighting

### Energy efficient office – low power density

<table><tr><td>Required luminance</td><td>500 lx</td></tr><tr><td>Dimensions:</td><td>A = 4m x 5m = 20 m²</td></tr><tr><td>η</td><td>0.7</td></tr><tr><td>MF</td><td>0.67 (acc. to DIN12464)</td></tr><tr><td>t</td><td>2000 h</td></tr><tr><td>lamp type</td><td>LFL 54 W → 4450 lm</td></tr><tr><td>power (per luminaire)</td><td>58 W → 77 lm/W</td></tr></table>

<figure><img src="image_137.png" /></figure>

### Simple calculation without maintenance and relamping costs

$$ 
\begin{array}{l}
\Phi = E \times A / (\eta \times MF) = 21 \text{ klm} \\
\text{for } t=2000\text{h} \rightarrow 42 \text{ Mlmh} \\
P = 21000 \text{ lm} / 77 \text{ lm/W} = 270 \text{ W} \rightarrow 13.5 \text{ W/m}^2 \\
\text{for } t=2000 \text{ h} \rightarrow W = 540 \text{ kWh} \rightarrow 27 \text{ kWh/m}^2
\end{array}
$$

<table><tr><td>Installation costs</td><td>31 €/m²</td></tr><tr><td>Energy consumption</td><td>27 kWh/m²,a</td></tr><tr><td>Costs for electricity (0.15 €/kWh price)</td><td>4.05 €/m²,a</td></tr><tr><td>Costs for electricity for 10 years</td><td>40 €/m²</td></tr></table>

### Life cycle costs with maintenance costs

<table><tr><td>Total life cycle</td><td>24 years</td></tr><tr><td>Maintenance interval<br>(cleaning and relamping)</td><td>6 years (n<sub>p</sub> = 4)</td></tr><tr><td>Maintenance costs</td><td>5 €/m²</td></tr><tr><td>Interest rate</td><td>6%</td></tr><tr><td>Electricity cost</td><td>4.05 €/m²,a (n<sub>p</sub> = 24)</td></tr><tr><td>Electricity price increase</td><td>1% / 5%</td></tr></table>

Present values of the total life cycle costs are
<table><tr><td>Installation</td><td>31 €/m²</td></tr><tr><td>Electricity</td><td>56 €/m² (1% annual increase)</td></tr><tr><td>Electricity</td><td>82 €/m² (5% annual increase)</td></tr><tr><td>Maintenance</td><td>20 €/m² (no annual increase)</td></tr></table>

Figure 7-10 shows the share of energy costs in life cycle costs in office lighting. The calculation is done over 24 years. The figure shows two examples of the increase of the electricity prices; one with 1% annual increase in electricity, and the other with 5% annual increase in electricity price.

<figure><img src="image_138.png" /><figcaption>**Figure 7-10.** Distribution of costs [€/m²] for office lighting during life cycle of an installation (24 years). Increase of 1% (left) or 5% (right) of the price of electricity has been considered.</figcaption></figure>

The standard EN 15193 defines limits for connected lighting power density. For office lighting the recommended power density is 15 -25 W/m², ranging from basic requirements (15 W/m²) to comprehensive requirements (25 W/m²). In the following, costs for office lighting are calculated with power density of 25 W/m², and presented in Figure 7-11. The installation costs are 50 €/m².

<table><tr><td>Total life cycle</td><td>24 years</td></tr><tr><td>Maintenance interval<br>(cleaning and relamping)</td><td>6 years (n<sub>p</sub> = 4)</td></tr><tr><td>Maintenance costs</td><td>5 €/m<sup>2</sup></td></tr><tr><td>maintenance costs increase</td><td>1%</td></tr><tr><td>Interest rate</td><td>6%</td></tr><tr><td>Energy consumption</td><td>25 W/m<sup>2</sup> x 2000 h = 50 kWh/m<sup>2</sup>year</td></tr><tr><td>Electricity cost</td><td>7.5 €/m<sup>2</sup>year (n<sub>p</sub> = 24)</td></tr><tr><td>Electricity price increase</td><td>1% / 5%</td></tr></table>

Present values of the total life cycle costs are

<table><tr><td>Installation</td><td>50 €/m<sup>2</sup></td></tr><tr><td>Electricity</td><td>103 €/m<sup>2</sup> (1% annual increase)</td></tr><tr><td>Electricity</td><td>153 €/m<sup>2</sup> (5% annual increase)</td></tr><tr><td>Maintenance</td><td>20 €/m<sup>2</sup> (no annual increase)</td></tr></table>

The increasing of the lighting power density up to 25 W/m² (maximum power density for office-rooms according to EN 15193) increases the energy costs significantly compared to the installation costs, Figure 7-11. When compared to Figure 7-10 and related calculations, the electricity costs are increased by about 85%.
<figure><img src="image_139.png" /><figcaption>**Figure 7-11.** Distribution of costs [€/m²] for office lighting during life cycle of an installation (24 years). Increase of 1% (left) or 5% (right) of the price of electricity has been considered. The lighting power density is 25 W/m².</figcaption></figure>

## Conclusions

There is lack of awareness of the fact that the variable costs (operation costs), especially the energy costs of a lighting installation during the whole life cycle, are mostly the largest part of the total costs, and that proper maintenance plans can save a lot of energy during the operating phase of the installation. Due to this lack of awareness in common practice, life cycle costs (LCC) and maintenance plans are very seldom put into practice. The calculations show that the management of LCC in the design phase can change the evaluation of different lighting solutions significantly. This adds weight to the energy aspects and thus influencing the final decision of the client to more energy efficient lighting solutions.

## 7.5 Long term assessment of costs associated with lighting and daylighting techniques

Fontoynont (2009) has studied financial data leading to the comparison of costs of various daylighting and lighting techniques over long time periods. The techniques are compared on the basis of illumination delivered on the work plane per year. The selected daylighting techniques were: roof monitors, façade windows, borrowed light windows, light wells, daylight guidance systems, as well as off-grid lighting based on LEDs powered by photovoltaics. These solutions were compared with electric lighting installations consisting of various sources: fluorescent lamps, tungsten halogen lamps and LEDs. Figure 7-12 shows the annual costs for various options (€/Mlmh).
<figure><img src="image_140.png" /><figcaption>**Figure 7-12.** Annual costs for various lighting and daylighting techniques (Fontoynont 2009).</figcaption></figure>

General results of the study were:

- Apertures in the envelope of the building are cost effective in directing light in the peripherical spaces of a building, mainly if they are durable and require little maintenance.

- Daylighting systems aimed at bringing daylight deeply into a building are generally not cost effective, unless they use ready-made industrial products with high optical performance and low maintenance, and collect daylight directly from the building envelope.

- Tungsten halogen lamps, when used continuously for lighting, are very expensive and need to be replaced by fluorescent lamps or LEDs.

- Depending on the evolution of performance and costs of LEDs and photovoltaic panels, there could also be options to generalize lighting based on LEDs and possibly to supply them with electricity generated directly from photovoltaic panels.

## References

* CML 2001. http://cml.leiden.edu/research/industrialecology/researchprojects/finished/new-dutch-lca-guide.html, accessed 6 November 2009.

* Eco-Indicator 2009. Eco-indicator 99 method. http://www.pre.nl/eco-indicator99/default.htm, accessed 30 September 2009.

* ELC 2009. European lamp companies Federation. Did you know...the potential energy savings of an energy efficient lamp? http://www.elcfed.org/1_health.html, accessed 17 September 2009

* EN 15193. Energy performance of buildings – Energy requirements for lighting, European Standard
Fontoynont 2009. Long term assessment of costs associated with lighting and daylighting techniques. Annex 45 Newsletter 1/2009, p. 3.

GDRC, 2009. The global development research center. http://www.gdrc.org/uem/lca/life-cycle.html, accessed 17 September 2009.

Gydesen & Maimann, 1991. Life cycle analyses of integral compact fluorescent lamps versus incandescent lamps. Proceedings of Right Light Bright Light, Stockholm, Sweden 1991. http://www.iaeel.org/iaeel/archive/Right-light_proceedings/Contents/RL1_contents.html

Hanselaer et al. 2007. Power density targets for efficient lighting of interior task areas. Lighting Res. Technology, 39,2 (2007) pp 171-184

LEDs Magazine 2009. Osram unveils life-cycle assessment of LED lamps, http://www.ledsmagazine.com/news/6/8/4, 6 August 2009.

DEFRA 2009. Life Cycle Assessment of Ultra-Efficient Lamps. Final Report to the Department for Environment, Food and Rural Affairs, 5th May 2009. http://www.defra.gov.uk/environment/business/products/roadmaps/lighting.htm
# Chapter 8: Lighting design and survey on lighting today and in the future

## Topics covered

<table><tr><td>8</td><td>Lighting design and survey on lighting today and in the future</td><td>205</td></tr><tr><td>8.1</td><td>Thoughts on lighting design</td><td>205</td></tr><tr><td>8.2</td><td>A technological approach</td><td>208</td></tr><tr><td>8.3</td><td>The role of LEDs</td><td>209</td></tr><tr><td>8.4</td><td>Architectural view on illuminants</td><td>210</td></tr><tr><td>8.5</td><td>Energy efficient lighting culture</td><td>211</td></tr><tr><td>8.6</td><td>Survey on the opinions of lighting professionals on lighting today and in the future</td><td>211</td></tr><tr><td>8.6.1</td><td>Introduction</td><td>211</td></tr><tr><td>8.6.2</td><td>Results</td><td>212</td></tr><tr><td>8.6.3</td><td>Summary and discussion</td><td>225</td></tr><tr><td></td><td>References</td><td>227</td></tr></table>
# 8 Lighting design and survey on lighting today and in the future

## 8.1 Thoughts on lighting design

“Primarily, it is light which brings materials to life and gives a room its form. A single beam of light allows for a surface to express itself and creates shadows behind objects”, states Tadao Ando, one of the most famous architects of light.

Lighting design is more than the planning of stipulated light intensities and luminance levels. Lighting design is also more than the fulfillment of physiological visual requirements of visual perception. The fulfillment of these requirements belongs to the necessary prerequisites of illumination. Lighting design is more than just the fulfillment of normative guidelines. Lighting design means the creation of an appearance (e.g. of a room), which complies not only with the technical requirements but also with the emotional and aesthetic requirements of the user.

Designing with light is based on psychological perception correlations, which cannot be measured quantitatively (at least at present), and therefore cannot be mathematically described or converted. Lighting solutions, in the sense of creations in light are very difficult to represent and communicate as they are abstract and can practically only be conceived by means of visual perception (one has to be able to see the solution). In order to be able to convey an illumination solution, they are either graphically represented (artwork) with the help of computer simulations (renderings), or represented by scale models. Ultimately, these are just aids and the true effects can only be experienced in a real situation.

From an architectural point of view lighting is a mean to express and underline the desired character of the building space, which may be defined by an overall design style of the architect.

Different places need different ways of lighting design. Anyway, it is possible to identify three main typologies of environments, each one characterised by different hierarchies of objectives, with a specific technical, functional or aesthetical priority:

a. Environments designed for work and services to the public: places where the functionality is the key element guiding the work of the designer, and the main aspects to satisfy are the rules of the vision and ergonomics, the safety and the communication

b. Environments designed for exhibitions and sale: places where the most important need is the image, be it faithful to the truth or distant to the reality, virtual, fascinating

c. Environments designed for residence and tourism: places where light should satisfy the need for comfort, relaxation, aesthetical value, status symbol

Visual perception is first of all a mental procedure, and not only a pure sensation (like e.g. a thermal sensation, which causes feelings of coldness or warmness). It is a means to receive information about our surroundings, about the distances, surfaces, textures, about what happens around us, and all this information arouses emotions. Our perception is very selective, prejudiced by our personal experience, and is influenced also by our actual mental state, history and expectations.

Through the visual perception system we receive the largest amount of information (most of it unconsciously) about our environment. Optical illusions are very popular to demonstrate this perception procedure: we interpret (unconsciously and not controllably) by a mental process what we are seeing (see Figure 8-1).
<figure><img src="image_141.png" /><figcaption>**Figure 8-1.** *Optical Illusion.*</figcaption></figure>

The picture in the Figure 8-2 is an example of a facade that is illuminated from the ground upwards, which causes very unusual shadows and thus is estranging the appearance of the building.

<figure><img src="image_142.png" /><figcaption>**Figure 8-2.** *Estrangement of a building facade by uplighting (Bartenbach 2009).*</figcaption></figure>

The comparison of two antithetic examples for shop lighting is shown in Figure 8-3. On the left picture many glaring light sources (no shielding) together with specular surfaces (floor, ceiling and shelves with ware) give a glittery appearance, whereas on the right side the light sources and luminaires are hidden, and the ware is in the focus.
<figure><img src="image_143.png" /><figcaption>**Figure 8-3.** *Comparison of shop lighting: left the light points are in the focus, right the ware (Bartenbach 2009).*</figcaption></figure>

Another example is the corridor lighting in Figure 8-4.: on the left is seen a shiny dark floor which appears like a black hole, and on the right surfaces which are made visible by the illumination.

<figure><img src="image_144.png" /><figcaption>**Figure 8-4.** *Comparison of two different floor lighting concepts (Bartenbach 2009).*</figcaption></figure>

In the museum lighting shown in Figure 8-5 the illumination idea was to use the fluorescent lamps themselves as art. The effect of such illuminations is obvious: the paintings are in the background.
<figure><img src="image_145.png" /><figcaption>**Figure 8-5.** *A special approach to museum lighting (Bartenbach 2009).*</figcaption></figure>

Figure 8-6 demonstrates how the appearance of illuminated paintings on a wall can be changed by simple measures. The change in the background reflectance from white to dark increases the visibility strongly.

<figure><img src="image_146.png" /><figcaption>**Figure 8-6.** *Comparison of two different backgrounds (Bartenbach 2009).*</figcaption></figure>

These few examples make it evident that lighting design is much more than the planning of stipulated illuminance levels.

The aim of an optimum lighting design is to achieve certain appearances and, at the same time, to fulfill the fundamental physiological and psychological visual requirements and to ultimately put the whole thing into effect in an energy efficient manner.

## 8.2 A technological approach

From an energy point of view, we can identify three steps that transform electrical energy into light: the lamp (light source, including controls and ballasts), the luminaire, and the room. The lamp transforms electric power into luminous flux, the luminaire distributes the light in the room, and the room transforms this light into visible luminances by the surface reflections.

The energetic performance of these different transformations are characterized by the factors
- lamp luminous efficacy (in lm/W, including operating devices)

- luminaire light output ratio (LOR, in %)

- room utilization factor (η, in %).

The ‘sum’ of these factors gives the ultimate (total) utilization of the electric light installation.

<figure><img src="image_147.png" /><figcaption>**Figure 8-7.** Supply chain from the electric power grid to the visual environment.</figcaption></figure>

The energy consumption of the installation is further defined by the operating times, i.e. the need for artificial lighting should be minimized by intelligent architecture and daylight harvesting. Proper controls (occupancy, daylight dependence, etc.) have to be installed to avoid needless operating of the artificial light.

The first key point for an energy efficient lighting installation is the choice of efficient lamps (characterised by the lamp luminous efficacy in lm/W), which produce the proper spectrum (correlated color temperature and color rendering index) and offer the required operating features. Besides the use of energy efficient lamps, the application of high quality luminaires (characterised by the LOR) together with efficient room lighting concepts (characterised by the η) and clever controls, are important for the visual and ecological quality of the whole lighting installation.

The luminaire should not only be a decorative element, but rather a device to distribute the light of the lamp according to the illumination tasks in the room without causing glare, thus creating together with the room surfaces the desired visual environment.

## 8.3 The role of LEDs

With the emerging LED technology a new white light source is available which offers a great potential for energy efficient lighting. With an efficacy of more than 100 lm/W in the near future, a lifespan up to 50000 h and more, and with easy control and dimming possibilities, LEDs offer all the key features for an energy efficient light source. Additionally, the light output ratios of LED-luminaires are usually much higher than for conventional light sources.

LEDs allow for completely new designs and architectures for lighting solutions, thus opening a new and wide field of creativity for all lighting professionals. At the same time, some old rules and
standards for a good lighting design are no longer applicable to LEDs (e.g. glare assessment, color rendering, light distribution, etc.). They demand some adjustments and sometimes also new rules, and this needs time to become a widespread and common accepted state of the art. In this transition period some meanders and mistakes will occur.

As an example, LEDs are very often used as replacement of low voltage incandescent lamps operated like a starry sky (many small light spots without any shading), but there are no clear rules for glare assessment of such an application. Another example is the color rendering topic, the commonly used CRI for lamps is misleading if applied to LEDs.

There is increased attention for biological (non-visual) effects of lighting in the lighting community. For these different biological effects of light special light spectra may be needed. Although the scientific basics are still too weak to be applied, lighting industry already offers a lot of so called 'dynamic lighting' solutions, e.g. to assist the daily activity and circadian rhythm of people. With the mixture of different LEDs it is possible to create almost any desired spectral distribution. This enables the creation of lighting environment for potential visual and biological effects for human beings.

## 8.4 Architectural view on illuminants

Light sources or illuminants are defined as devices which transform electrical power into luminous flux. A luminaire is a device which is necessary for the operation of an illuminant. It consists of a lamp holder, an operating device for the illuminant together with the necessary electrical wiring, a mechanical construction including a housing and the light directing elements (reflectors, prisms etc.). These light directing elements serve to distribute the light according to requirements and also to shield or fade-out the illuminant.

An architect views the luminaire as a visible part of the interior decoration, whereas a lighting engineer considers it as a device which fulfils the photometric requirements. The lighting designer however, wants to be creative with light and to achieve effects. For architects, aesthetic demands on the body of a luminaire (housing) and its arrangement in a room is paramount. On the other hand, the lighting engineer has the photometric requirements in mind (illuminance, glare values, etc.), which come from relevant regulations and the experience of the engineer. The lighting designer, in turn, works with the emotional effects of light, as one can observe from the work of a theatrical stage illuminator. In this case, the spotlights themselves are not important and are rarely visible. Photometric values and requirements are also unknown, only the emotional effect on the stage is what counts.

In accordance with these considerations, the effects of a lighting system can be divided into the following three categories:

- The body of the luminaire as a component of the architecture (decorative)

- The purely visible effect of the light (makes things visible)

- The associated aesthetical and emotional effects.

Depending on the objective, the lighting system has its focal point in one of these three categories, but ultimately it is a combination of all effects. Therefore, all of these aspects must be collectively considered. A good lighting design, whether from a specialist or a generalist, always considers these effects as a whole. In the future, further aspects will be more intensively considered. These aspects include energy consumption, environmental impact, maintenance, and cost of the illumination over a life cycle.
## 8.5 Energy efficient lighting culture

It is essential that in future lighting design practices, maintenance schedules and life cycle costs will become as natural as illuminance calculations already are. A sustainable lighting solution includes an intelligent concept, high quality and energy efficient lighting equipment suitable for the application, and proper controls and maintenance.

There are activities and efforts underway in Europe (e.g. by CELMA, ELC) to establish a Lighting Design Legislation, which should make sure lighting design follows energy efficient rules in the future. Due to the fact that the objectives of a lighting system can differ, and that there can only be limited standards for architecture and design, we must take care in our endeavor to regulate these areas and to implement limitations. For example, if we set our limitations for the power input per unit area too low, not only the architectural, but also the photometric leeway can be lost and only a trimmed standard illumination with minimal energy consumption would be possible. On the other hand, if we set such a leeway too loose, there would be no effect on energy efficiency.

A more promising prospect seems to be by means of information, clarification and the raising of awareness, together with well targeted technical advancement. This can help to increase the awareness of lighting so that predominantly good and energy efficient lighting solutions will be put into practice.

We have to be careful to avoid overregulation, and we cannot forget that lighting design is essentially a creative design process.

## 8.6 Survey on the opinions of lighting professionals on lighting today and in the future

### 8.6.1 Introduction

The survey was conducted during 2006-2007 and the opinions as presented here reflect those of the respondents.

Part of the Annex 45 work was to identify knowledgeable people in the lighting community and to collect information. The goal was to find out how lighting has been developed in different countries within last 5 to 10 years and how people see its development in the future. The experts were also asked what kind of information about (energy efficient) lighting is needed and in what form this information should be provided.

A questionnaire template was sent to key contacts of Annex 45 and they could decide whether to do it by interview or by sending back the filled questionnaire. Altogether twenty-five answers were received from the following eleven countries.

<table><tr><td>— Austria</td><td>1</td></tr><tr><td>— Belgium</td><td>2</td></tr><tr><td>— Canada</td><td>2</td></tr><tr><td>— China</td><td>4</td></tr><tr><td>— Finland</td><td>3</td></tr><tr><td>— France</td><td>3</td></tr><tr><td>— Germany</td><td>1</td></tr><tr><td>— Italy</td><td>4</td></tr><tr><td>— Russia</td><td>1</td></tr><tr><td>— Turkey</td><td>3</td></tr><tr><td>— Sweden</td><td>1</td></tr></table>
The members were from the research, manufacturing or application sectors. The following topics were covered in the interview questionnaires:

- Background of the respondent

- History and state of art

- Meaning of lighting for the comfort of indoor environment, health and productivity

- Future of indoor lighting, light sources, installations, integration, automation, daylight, developing needs

- Energy efficiency, life cycle, environment

- Flexibility, changeability and dynamics of lighting

- Automation

- LEDs

- Information and standardization

- Summary

## 8.6.2 Results

### Background

Respondents were asked about their experience in the lighting field and also the activities of their companies in the lighting field. If the company had several activities it was classified by the main field of activities. For instance, manufacturers often have also R&D but they were classified as manufacturers.

<figure><img src="image_148.png" /><figcaption>Figure 8-8. Companies' (represented in the survey) activities in the lighting field.</figcaption></figure>

### History and state of art

#### How has lighting been changed during last 5 to 10 years

When people were asked how lighting has been changed during the last 5 to 10 years, more than half of the respondents mentioned the increased demand for energy efficiency or energy savings. The second largest group mentioned the increase of CFLs and the increase of (small) gas discharge lamps (mainly metal halide lamps) in indoor lighting. After that, the arrival of T5-lamps and the increased use of electronics in the lighting market were mentioned.
The increased use of electronic ballasts as well as the increase of control and the integration of control to building management was indicated. Luminaire design has been changing with the new lamps (for instance T5), but also due to new materials. The use of daylight is increasing, partly due to energy savings demand, and this was also related to the increased use of control systems.

The importance of lighting design was mentioned and it was indicated that nowadays it is no longer just electricians that do the design. At the same time, designing has become much easier because of powerful computer tools. The increase of lighting quality, LEDs, reduction of incandescent lamps, dynamic lighting and reduced operational costs were also mentioned in the survey.

<table><caption>**Table 8-1.** How has lighting (techniques, design, installation, use and maintenance) been changing during the last 5 to 10 years?</caption><thead><tr><td>How lighting has been changing</td><td>No. of responses</td></tr></thead><tbody><tr><td>Increased energy efficiency (of lighting, luminaires, ballasts) and environmental friendliness</td><td>13</td></tr><tr><td>Increase of CFLs, small gas discharge lamps</td><td>9</td></tr><tr><td>Increase of T5 lamps</td><td>7</td></tr><tr><td>Introduction of electronics, digital technology</td><td>7</td></tr><tr><td>Control (intelligent, digital, integration in building management)</td><td>6</td></tr><tr><td>Luminaire design, easier to install, better materials</td><td>5</td></tr><tr><td>Daylighting</td><td>5</td></tr><tr><td>Lighting design more important but easier (faster)</td><td>4</td></tr><tr><td>Focus on lighting quality and well-being, health</td><td>4</td></tr><tr><td>LEDs are entering</td><td>3</td></tr><tr><td>Reduction of incandescent lamps</td><td>2</td></tr><tr><td>Dynamic lighting (CCT change)</td><td>2</td></tr><tr><td>Reduced operation costs (through increased lamp life, lower wattages)</td><td>1</td></tr></tbody></table>

### The problems of current technology

Table 8-2 lists the problems of current technology as indicated by the survey. The most evident problem was the price of the products; nine respondents out of twenty-five mentioned the price.

<table><caption>**Table 8-2.** Problems of current technology.</caption><thead><tr><td>Problems of the current technology</td><td>No. of responses</td></tr></thead><tbody><tr><td>Price (costs)</td><td>9</td></tr><tr><td>Reliability of electronic ballasts</td><td>4</td></tr><tr><td>Size and shape</td><td>3</td></tr><tr><td>Lack of knowledge of best option for the customer, marketing confusing</td><td>2</td></tr><tr><td>Old installations are not renovated</td><td>2</td></tr><tr><td>Efficiency</td><td>2</td></tr><tr><td>Life time</td><td>2</td></tr><tr><td>Compatibility of components from different manufacturers, standardization</td><td>2</td></tr><tr><td>Problems with lighting controls, lack of control standards</td><td>2</td></tr><tr><td>Market is slow (takes long time until a new technology can be established on the market)</td><td>1</td></tr><tr><td>Glare (T5 and LEDs)</td><td>1</td></tr><tr><td>Feasibility</td><td>1</td></tr><tr><td>Acceptance by users</td><td>1</td></tr><tr><td>Lighting design not paid attention</td><td>1</td></tr><tr><td>Communication between different players</td><td>1</td></tr><tr><td>Lack of educated professionals</td><td>1</td></tr><tr><td>Transition period between old and new products</td><td>1</td></tr><tr><td>Mercury</td><td>1</td></tr></tbody></table>
Four respondents mentioned the reliability of electronic ballasts. Three respondents were referring to size and shape of CFL lamps and the fact that they do not fit into old incandescent luminaires. Compatibility of components from different manufacturers was also mentioned related to CFLs and their ballasts. It was also pointed that customers are lacking information on the best options and the marketing can be misleading. Two respondents mentioned that the old installations are not renovated and that there is still need for further improvements in efficiency and life time of products.

*How should manufacturers improve their products?*

Respondents were asked how manufacturers should improve their products. They could freely express their opinions on the subject and arrange the given nine characteristics of the products in an order from most important to least important. Figure 8-9 shows the aspects that were considered in the survey and the survey results. The largest group of respondents chose energy efficiency as the most important character to be improved.

The respondents also mentioned that manufacturers should communicate more with lighting designers and researchers. The lack of standardization was also mentioned. It was pointed out that new technology has defects in the early stage. Also, more energy saving technology such as PIR sensors was requested.

<figure><img src="image_149.png" /><figcaption>**Figure 8-9.** Analysis of how manufacturers should improve their products.</figcaption></figure>

*Usage, maintenance, needs of development*

Opinions on the usage and maintenance of lighting included:

- Significance of the total costs of ownership: More consciousness of this would lead to much higher rate of renovation of lighting, and thus save a lot of energy.

- Maintenance has become more expensive: electrician is needed quite often, faults are expensive, and conventional ballasts more reliable, electronic ballasts becoming more reliable than they were five years ago.

- To make green design a reality, utilities and governments have to work in synchronization with manufacturers and building owners to stimulate the
use of the most efficient technologies and to compensate for the premium costs until market is transformed. Incentives, tax deduction, real estate appraisal are good examples.

- More control systems solutions oriented at energy savings and user comfort.

## Meaning of lighting for the comfort of indoor environment, health and productivity

### View of the importance of human factors (well-being, health, productivity, visual environment) in the future lighting technology

### What kind of research is needed? Did you note the importance in your own activities?

The answers for these questions highly reflected the need for more research; 64% of all the respondents expressed the need for more research. They wanted also guidelines and solutions. Few examples of the answers:

- Research on impact of design on vision and human health

- Health, productivity and well-being are very important aspects and much more research is needed to understand the impact of lighting on these quantities.

- Much more research and dissemination is needed to increase the knowledge and awareness on the visual and non-visual effects of lighting. This is a precondition to reach a higher state of the art for our lighting solutions.

- Importance mostly not noted

- There is a lot of research but each study is on a small scale. There is a need for a comparison of all the studies and giving overall conclusions. Industry is interested in more studies on the effects of dynamic light.

## Future of indoor lighting, light sources, installations, integration, automation, daylight, most important developing needs

### New light sources and ballasts

Two thirds of the respondents mentioned LEDs when they were asked what new light sources are coming on the market. Nine respondents mentioned that electronics, intelligence and communications are increasing (wireless or with wire). It was expressed that the market wants more energy efficient lighting and products with longer life-time.

<table><caption>**Table 8-3.** New light sources coming on the market.</caption><thead><tr><td>New light sources, their components & their important features</td><td>No. of responses</td></tr></thead><tbody><tr><td>LEDs</td><td>16</td></tr><tr><td>Electronics, intelligence, sensors, communication is increasing</td><td>9</td></tr><tr><td>More energy efficient lighting</td><td>5</td></tr><tr><td>Longer life</td><td>4</td></tr><tr><td>Dimmable/smaller wattages high pressure discharge lamps</td><td>4</td></tr><tr><td>More efficient ballasts</td><td>2</td></tr><tr><td>Mercury free lamps</td><td>1</td></tr><tr><td>Controllability</td><td>1</td></tr><tr><td>Take into account visual and non-visual effects</td><td>1</td></tr></tbody></table>

### Barriers for new light sources

Price seems to be the most important barrier for the entry of new light sources in the market. The
respondents were also concerned about the quality and performance of new products. It was seen that the pay-back time of new products can be rather high. It was seen that the markets are conservative and it takes time before new products are approved. On the other hand, since volumes are big it takes also time for the manufacturers to change volumes. Some respondents expressed that the management of lighting is becoming more complex and there is lack of standardization and that some dimensions can be inappropriate (CFLs vs. incandescent lamp).

<figure><img src="image_150.png" /><figcaption>**Figure 8-10. Barriers for new light sources.**</figcaption></figure>

## Trends in luminaires

According to the survey the trend in luminaires is that they will become more efficient in the future. It was seen that energy efficiency will also improve through better lamps and ballasts, better reflectance materials and optics. It was expressed that the design of a luminaire (in-fashion appearance) is becoming more important and luminaires will become smaller; luminaires should be environment-friendly and then parts should be recyclable. Indirect lighting was seen as one trend, although one respondent considered this something that should be avoided.

<figure><img src="image_151.png" /><figcaption>**Figure 8-11. Trends in luminaires.**</figcaption></figure>
## Control methods

When the respondents were asked about the future of lighting control methods most often they mentioned wireless control. Wireless control was also seen as a way for individual dimming and easy access. On the other hand one respondent said “People go in and out of their rooms in their routine work and don’t think about the light. At the beginning it is fun, but then the lighting is left the way it is”. It was seen that the control systems enable energy savings and the use of daylight. Future possibilities of lighting control were seen as dynamic lighting (variable color temperature), intelligent control and adaptive, learning systems.

<table><caption>**Table 8-4.** Future lighting control methods.</caption><thead><tr><td>Lighting control methods</td><td>No. of responses</td></tr></thead><tbody><tr><td>Wireless control</td><td>7</td></tr><tr><td>Daylight use, energy savings</td><td>6</td></tr><tr><td>Integration to other building systems</td><td>4</td></tr><tr><td>Individual, personalised dimming</td><td>3</td></tr><tr><td>Easy access, user friendly</td><td>3</td></tr><tr><td>Dynamic lighting (variable CCT)</td><td>2</td></tr><tr><td>Intelligent control</td><td>1</td></tr><tr><td>Self learning systems</td><td>1</td></tr></tbody></table>

## Vision of the exploitation potential of daylight and the needs for development to achieve the exploitation potential, the biggest barriers on the point of view of one's own country

In principle all the respondents that answered this question considered the use of daylight as useful for energy savings, visual comfort, health and well-being. Artificial lighting was also seen as a supplementary light source supplementing and assisting daylight during the daytime.

However, the respondents also found barriers for the use of daylight:

- Lack of general awareness and knowledge of energy saving potential: in many cases the energy efficiency has to compete with low-cost solutions in order to meet budget restrains

- Uneven luminous distribution in the room in daylight conditions

- Lighting design is very important in order to create proper environment for visual tasks

- Architectural designs are made by aesthetic and local concerns not taking sunlight into considerations.

- Control of artificial lighting has to be done automatically

- Investment costs, difficulties to estimate energy savings

- Thermal problems in summer

The solutions were seen as:

- More education and know-how workshops for architects and electrical/lighting consultants

- Financial and design incentives

- More attention by both architects and lighting designers

## Lighting design

The respondents view was that in many cases lighting design is carried out as a side task by people (electrical designers) with low level of expertise in lighting field.
It was expressed that the customers might not be ready to hire lighting designers as they may be
unaware of the impact of lighting on the operational costs. It was seen that poor designs are unable
to make use of the energy saving potential of a building. The view was that there is a large potential
for lighting design to affect the energy efficiency and that good lighting design will have benefits
both in energy saving and good performance. It was seen that lighting designers are necessary and
ought to be paid for their job; lighting is the last phase during the design and construction, the
moment when money runs out.

***The solutions were seen as:**

— Raising public awareness about lighting design

— Integrate the lighting design in the start of the building design

— The electrical consultant and the lighting industry have a strong impact to make the decision makers understand. Within 3-5 years the market will be ready to pay for energy saving lighting designs.

***Energy efficiency, environment***

The experts were asked what actions are the most important in order to improve the energy economics of lighting. They were given three alternatives and the possibility to freely formulate their answer. They were allowed to give more than one answer and therefore all the specified answers were frequently mentioned: "More energy efficient lamps/luminaries" (24 answers), "automation" (22 answers) and "life cycle analysis" (14 answers). Better maintenance, intelligent lighting concepts, including daylight utilization, and quantitative explanations for quality improvements were also mentioned. In the question "what things have to be considered on the environmental issues of lighting" there were also three alternatives and a free formulation possibility. Again, the specified answers were often mentioned: "The long life of lamps/luminaries" (19 answers), "the energy efficiency of lamps/luminaries" (24 answers), "the small environmental burden of lamps/luminaires (in the production, use and disposal/recycling)" (16 answers).

<figure><img src="image_152.png" /><figcaption>**Figure 8-12.** Payback time of additional costs of energy efficient lighting and environmental friendly technology.</figcaption></figure>

Thirteen answers saw that the payback time of the additional costs of energy efficient lighting should be less than 3 years, while ten answers saw that the payback time should be 3 to 5 years. One respondent expressed that the payback time should be less than 3 years in domestic lighting and from 3 to 5 years in industrial lighting.
The view was that the payback times of additional costs of environment-friendly technology can be slightly higher: there were 10 answers for payback time of less than 3 years, nine answers for 3 to 5 years, five answers for 5 to 10 years and one answer for more than 10 years.

## Vision of the energy efficiency of lighting in a 5 to 10 year period

- LEDs will probably be significant for general lighting in 10 years

- Efficacy of lamps will increase, integrated lighting concepts and technologies will allow realizing energy saving lighting concepts

- Technology improvements, directives and requirements will be made

- Customers will be interested in energy savings because of the electric bill

- The lighting design might focus more on additional benefits such as health-related aspects or productivity. If these effects can be included in an overall cost/benefit calculation, it could make way for many innovative technologies.

- There is limited possibilities for light sources to improve by raising the luminous efficacy, but a lot of things can be done to luminaries. Market penetration depends not only on the effect of saving energy but also on the cost to get this energy cut. This also implies the barriers for new technology, because more often new technology means more costs.

- With institutional intervention, the market is shifting and will shift more and more

- Disappearance of old fluorescent lamps (T12) and electromagnetic ballasts, great penetration of T5 and CFL lamps

- Costs will probably decrease; that will improve the market. Better and more control systems (too little nowadays).

- W/m² will drop down

- Directives will improve the efficiency.

- With the development of lighting technology, the energy efficiency will be higher and higher, this is especially for LEDs.

- New lighting products will improve energy efficiency, LEDs, low wattage HID lamps, and fluorescent lamps with high luminous efficacy.

- Energy is becoming very expensive and every sector has to give importance to it.

- Incandescent lamps will be banned.

- To be on the top of the list for energy saving activities in the building process. To day it is insulation, change of windows etc, which take the money for the lighting installation.

## Barriers:

- Costs, stocking and unadjusted marketing directions

- Main barriers will be in the budget for a building.

- Old installations: there is no urge to change them and if they are working they are not changed

- With LEDs the barriers are the packing technology and thermal issues.

- LED luminaires produce electronic waste

- Materials (for instance, fluorescence powder) and packing technology

- New technologies are under the monopoly of specific firms and are being directed by them. Therefore new products are very expensive when they
enter the market.

## Vision of the environmental issues in a 5 to 10 year period

- Mercury content reduction

- Government regulations could be the only major factor to improve environmental aspects of lighting

- Reduction of toxic materials in products (lamps, luminaires, etc.) and in the production process.

- Environmental issues are used for marketing.

- Legislation, image, environmentally-friendly solutions, although usage is more important than technical solutions.

- The application of environmental friendly technology should be promoted by the government.

- Also new technology can be harmful to the environment (e.g. content of mercury). The light sources are beneficial to the environment in two ways, one is the benefit coming from them spending less energy, and the second is the efficiency of the new technologies, and the increased product life.

- Materials recycling.

- Ecology becomes a business.

## Flexibility, changeability and dynamics, is it important and in what applications?

### Automation

### Is the changeability of the lighting important?

### In what kind of property the physical changeability of the lighting is especially important?

The physical changeability of the lighting was found especially important in office buildings (23 answers), clinical health care (19 answers) and educational buildings (19 answers). All the beforehand defined building types were mentioned by only a few respondents. Table 8-5 shows the survey results on the importance of dynamics of lighting (amount of light, color) in different building types. Dynamics was also found to be important in offices and clinical health care buildings. In residential buildings and shops dynamics was mentioned more than the physical changeability of lighting.

<table><caption>**Table 8-5.** In what kind of property the physical changeability and dynamics of the lighting are especially important.</caption><thead><tr><td>Building type</td><td>Physical Changeability</td><td>Dynamics</td></tr></thead><tbody><tr><td>Office building</td><td>23</td><td>22</td></tr><tr><td>Health care, clinical</td><td>19</td><td>20</td></tr><tr><td>Educational building</td><td>19</td><td>16</td></tr><tr><td>Health care, not clinical</td><td>14</td><td>14</td></tr><tr><td>Residential building</td><td>13</td><td>16</td></tr><tr><td>Shop building</td><td>13</td><td>15</td></tr><tr><td>Sports building</td><td>12</td><td>13</td></tr><tr><td>Assembly building</td><td>12</td><td>12</td></tr><tr><td>Accommodation building</td><td>12</td><td>11</td></tr><tr><td>Catering building</td><td>8</td><td>9</td></tr><tr><td>Penitentiary building</td><td>8</td><td>8</td></tr></tbody></table>
**What is your opinion about the future of the lighting automation?**

Nine answers mentioned that the lighting automation is good and economical investment, ten mentioned that it is good but there are barriers and it is uneconomical, one considered it to be good but uncertain functioning is a problem and two made other points. One respondent saw that before automation there is the intelligence of usage and others saw that automation is good mostly for visual comfort.

**What benefits do you except to gain from the automation of lighting**

Energy savings was clearly the most important factor that respondents expected to gain from automation, Figure 8-13.

<figure><img src="image_153.png" /><figcaption>Figure 8-13. What benefits do you except to gain from the automation of lighting?</figcaption></figure>

**Light emitting diodes (LED)**

**New technology and its integration for building services**

- Still at small scale use in lighting applications, but already very efficient for colored lighting, EXIT signs with LEDs are common, small accent and step/ night lighting with LEDs is more usual to buildings

- LEDs offer a new trend in lighting as they allow completely different luminaire design. There are still some problems in operating them and these problems have to be solved (thermal issues, color etc.)

- Higher and higher lumens output in one package. More stable operation

**Where do you see applications for LEDs?**

- LEDs can be useful in accent lighting or in environments that require low lighting levels (e.g., patient rooms at night time), retail (dynamic-color lighting, floodlighting of vertical surfaces, delineation (replacing neon) and seasonal lighting

- Indoor lighting, specialized area lighting (small size allows to be operated in hard-to-reach areas). They can be dimmed easily and have a long lifetime so that they offer quite a few chances in the overall dynamic lighting field.

- LEDs are already being used in traffic lighting, architectural lighting, safety lighting

- At the moment there is only a niche market for special applications, but this will change rapidly in the next 5-10 years. LEDs outperform traditional lamps with their superior lifetime, they offer the possibility of
spectral mixing, are free of IR/UV and very robust. Ongoing improvements in LED technology indicate, that in the near future LED prices are decreasing rapidly, the efficiency is further increasing which opens the way for LED's to be the light source of the future with a broad field of applications.

- Outer wall of sky-scrapers, screen of large scale, automotive lighting, flashlights, indicators

- Building surface, background lighting

- Mainly for decorative lighting

- General lighting, traffic lighting, vehicles lighting, every lighting application

## Ways of illumination?

- Rather than conventional, better and more innovative, as part of decorative elements, wall/ ceiling grid, etc. Cost and innovative technologies are the barriers

- Backlighting of monitors, task lighting, ambient lighting, etc., many setups possible

- Optical efficiency, directed lighting

- Easy to focus on what needs to be illuminated

- For small surface or area

## Structure of luminaires

- Stand alone (more classic) or integrated into the construction elements

- Luminaires holding LEDs can shrink in size allowing a "lighter" design of the interior.

- Smaller luminaires, integrated in furniture

- Temperature and glare has to be taken into account

- The conventional luminaire industry is not well suited for these new techniques, instead of mechanical (spinning, hydroforming etc. of reflectors, mounting, casing) and electrical construction electronic and small optical construction and manufacturing is necessary

- Panel-like luminaires, linear luminaires

- The smaller the better

- Should release heat easily

- Great flexibility in design, smaller or bigger luminaires.

- LEDs evolve quickly, that is a difficulty for the luminaire manufacturers

## Low voltage

- Quite suited for this application

- If low voltage can be supplied easily this allows specialized solutions in fields where electrical safety is extremely important.

- Makes easier to hide wires, no electricity hazards, no problems with the temperature like with halogen lamps

- Low voltage is more safe and convenient

- Advantage for some applications: Wall, floor, under the hand, under table, in the seat; the very easy utilization with batteries will create a specific sector for itself.
## New installation practices?

- Correct installation of LEDs will require specialized contracting teams that have their own designers and can control the purchase, installation and commissioning of the LED design

- This will be answered in the future by applying it in the real world.

- LED-luminaires may produce electronic waste (trend to throw away elements and luminaires, no replacements due to long life time). We have to establish industrial standards for LEDs itself, holders, controls etc. (comparable to the ones for common light sources) to encourage sustainable LED luminaire design.

- Only in detail, does not have many effects on macro platform

- Yes, due to the long lifetime

## Integration in building structures and to other energy systems

- Requires a lot of careful planning and may need specialized sub trades

- I do not see any difficulty in integrating LED luminaires in buildings. Ballasts can be designed such that they can be controlled by building management systems.

- Integration to furniture, OLEDs can be used, for instance, as wall papers

- Lumen maintenance, costs

## What are the worst barriers?

- Cost and knowledge of procuring the right equipment for the application

- Thermal management issues, luminous efficacy, color rendering

- Users are slow to accommodate, building life cycle is long

- Reliability, lamp life, price

- Glare, price, energy efficiency (at the moment)

- Industrial standards are not available (holders, control and ballast, platines, etc.). High prices, high risk (not fully developed state at the moment, LEDs in practice do not fulfill the promises), fast developing LEDs.

- Lumens efficiency, packing technology, second optical design

- Heat, the lack of standard and the fact that the optics are not specified yet. The concepts haven't found their place yet.

- Let's not say barriers, but disadvantages; it hasn't reached high power values yet, highly efficient light has not been obtained yet, secondly we can't use it as easily as it would have been in normal network voltage, in addition to that there's the heat problem in high power LEDs. The LED is small but for cooling it, 50 grams of aluminum cooler is used per 1 gram of LED.

- Reliability

- Not possible for the owner to know about the durability of the installation.

## Information and standardization

### What is your level of knowledge on standards, directives, recommendations, energy efficient techniques and design?

Fifteen respondents answered that their knowledge is high or good. Three answers mentioned that
their knowledge is common or adequate.

**Is education needed on energy efficient lighting/technologies?**

Sixteen respondents answered yes.

**Is public actions needed to promote new technologies?**

Sixteen respondents answered yes. Three respondents said that there already exist standards; two of them considered that the standards are not used enough.

**Who should act as sources for neutral information concerning new technologies?**

Few respondents said that information is needed from all sources. It was also pointed out that research institutes do not necessarily have the funding for the information delivery.

<table><caption>**Table 8-6.** Who should act as sources for neutral information concerning new technologies?</caption><thead><tr><td>Who should act as information sources</td><td>No. of responses</td></tr></thead><tbody><tr><td>Research institutes</td><td>25</td></tr><tr><td>Associations like Illuminating Engineering Societies</td><td>18</td></tr><tr><td>Manufacturers organizations</td><td>10</td></tr><tr><td>Private info services</td><td>9</td></tr><tr><td>Others: utilities, governments, press, governmental organizations etc.</td><td>4</td></tr></tbody></table>

**Are you ready to pick up information? From what areas of lighting more information is needed?**

Information is needed about the total costs of the lighting (17 answers out of 25). Information is also needed about the systems and the choice of lamp type and luminaires (16 answers). Energy efficiency (15 answers) and choice and use of control equipment in different installations (13 answers) were also often mentioned. It was seen that more information is needed about techniques, environmental issues, lamp lives and illumination design. Information should be provided by different means, the most popular was internet (21 answers), seminars (19 answers), brochures (18 answers) and CDs (10 answers).

<figure><img src="image_154.png" /><figcaption>**Figure 8-14.** From what areas of lighting more information is needed.</figcaption></figure>
### 8.6.3 Summary and discussion

In the summary the respondents were given a list of issues of lighting and asked how important they considered them. They could rate each issue from 1 to 6 (1 being not important and 6 very important). They were asked both their own priorities and also what they think that the end-user would appreciate. The same number could be given more than once for different issues. The results are shown in Figure 8-15.

Most of the issues were considered important, energy efficiency being the most important. The average value given to energy efficiency was 5.5. However, the respondents did not think that the end-user values it as much. The average value for end-user was 4.3. Quite large differences between the opinions of respondents and what they think the end-user appreciates were also found in positive impact to health (respondent 5.4 versus end-user 4.6), longevity (5.2 vs. 4.1), increase productivity (5.0 vs. 3.9), environmentally friendly (4.7 vs. 3.3) and technical progressiveness (3.9 vs. 2.8). The respondents view was that the end-user appreciates appearance (5.1), amount of light is enough (4.8), price (4.8), quality of lighting (4.7) and energy savings (4.7). The issue trendy was valued for 3.9 by respondents and 4.0 by what respondents thought end-users appreciate.

<figure><img src="image_155.png" /><figcaption>Figure 8-15. Importance of different issues of lighting.</figcaption></figure>

The respondents were also asked if they think that lighting has an effect on different aspects of property. They could value them from 1 (not important) to 6 (very important). The average values are shown in Table 8-7.

<table><caption>Table 8-7. Evaluation of lighting effect on different aspects of property.</caption><thead><tr><td>Evaluation feature</td><td>Average given</td></tr></thead><tbody><tr><td>Satisfaction of the users</td><td>5.3</td></tr><tr><td>Quality</td><td>4.7</td></tr><tr><td>Desirability as a working place</td><td>4.7</td></tr><tr><td>Image of the company</td><td>4.5</td></tr><tr><td>Easiness of renting/selling of property</td><td>3.8</td></tr></tbody></table>
The survey indicated that energy efficiency of lighting has been increasing during the last 5 to 10 years. This has happened through more efficient light sources like compact fluorescent lamps and T5-lamps and also through the increase of electronics (electronic ballasts) and control. Problems of the current technology were seen to be high price and reliability. On the other hand, it was seen that the market is slow and it takes time before the new technology can be established on the market. Further improvements on energy efficiency are still needed. When asked how manufacturers should improve their products 14 respondents out of 25 said that they should improve the energy efficiency.

Human factors (well-being, health, productivity, visual environment) were considered very important. But the general opinion was that there is not enough knowledge on these and more research work is needed to understand the impact of lighting on human factors.

The survey indicated that in the future new light sources on the market are LEDs and dimmable and/or small wattage high pressure discharge lamps with longer life times. It was also seen that electronics, intelligence, (wireless) dimming, sensors and communication are becoming more commonly used. The view was that the luminaire efficiency (light output ratio) is increasing. Barriers for new products were seen to be the price (long payback time and also the lack of information of the total costs), reliability and the conservativeness of the market. It takes time before new products are approved and on the other hand since volumes are big it takes also time for the manufacturers to change volumes. The majority of the respondents answered that the payback time for the additional costs of energy efficiency should be less than 5 years (85% of answers) and moreover 37% answered that it should be less than 3 years. The attitude for the additional costs of environmentally friendly technology was parallel, 76% saying that the payback time should be less than 5 years and 36% said that it should be less than 3 years.

The respondents saw that in the future, the energy efficiency will increase through technology (LEDs, CFLs, T5s, luminaires) and also because of the increase of the electricity price. Further causes for improve in energy efficiency were seen the new directives and requirements (for instance, the ban of incandescent lamps). Energy savings was found to be the most important factor to be gained from automation.

The respondents expressed that LEDs are coming on the market, but at the moment LEDs are on special applications like traffic lighting, architectural lighting and safety lighting. Thanks to lowering prices and increasing efficacy and long lifetime LEDs will be the light source of the future with a broad field of applications. It was seen that LED luminaires will be smaller, perhaps integrated in the furniture or construction elements. Barriers for LEDs were seen to mainly be high price, thermal management issues (need for heat sink) and luminous efficacy. As barriers, the lack of standards and glare and the durability of the installation were also mentioned. The respondents view was that education and also society's actions are needed to promote energy efficient lighting; research institutes were seen as the best source of neutral information.

According to the survey there is demand of energy efficient products in the market. In the near future this demand will be increasing through the increase in prices of electricity, the increasing awareness of environment, and directives and requirements. However, it was seen that the energy efficiency of lighting products has been increasing for last 5 to 10 years with new light sources, electronics and control systems. The view was that full advantage has not been taken of the new products which are already in the market, as lighting market is conservative and the renovation rate is slow.
The survey indicated that information of the new technologies should be provided to the end users, and also public actions and awareness are needed to promote energy efficient lighting technologies.

## References

Bartenbach 2009. Bartenbach Lichtlabor, Austria
# Chapter 9: Commissioning of lighting systems

## Topics covered

9 Commissioning of lighting systems.................................................................................. 231

9.1 Definition of Commissioning.................................................................................. 231

9.2 Definition of the Commissioning Process.................................................................. 232

9.3 The commissioning plan: A tool to structure the commissioning process.................. 235

9.3.1 Standard model of commissioning plans.......................................................... 236

9.3.2 Checklist ............................................................................................................ 236

9.3.3 Matrix for quality control............................................................................ 237

9.4 How to execute the commissioning plan .................................................................. 237

9.4.1 Functional performance testing (FTP).......................................................... 237

9.4.2 Using the building control system for commissioning .................................. 238

9.4.3 Using models at the component level .......................................................... 239

9.5 Applying commissioning process to the lighting control system .......................... 240

9.5.1 Objectives of lighting systems.................................................................... 240

9.5.2 Criteria for lighting systems quality .......................................................... 240

9.5.3 Indicators to evaluate the performance of lighting system .......................... 240

Luminance distribution ........................................................................................ 240

Illuminance ............................................................................................................ 241

Glare........................................................................................................................ 241

Directionality of light........................................................................................ 241

Color aspects............................................................................................................ 241

Flicker .................................................................................................................. 241

Maintenance factor.......................................................................................... 241

Energy considerations........................................................................................ 242

Daylight.................................................................................................................. 242

9.6 Example of a Commissioning Plan applied to the lighting system........................ 242

References.................................................................................................................. 244
# 9 Commissioning of lighting systems

## 9.1 Definition of Commissioning

The demands of building users regarding the built environment are growing. We all want a comfortable and healthy indoor environment but excessive use of natural resources and pollution of outdoor environment we do not accept any more. The energy consumption and the energy costs should indeed be kept on a low level. The heating, ventilation and air conditioning (HVAC) industry seeks solutions to fulfil these higher requirements. Many new products and systems are developed such as high efficiency generation systems using renewable energy sources, low energy cooling systems, natural ventilation systems and integrated control systems. We are clearly leaving the time of low efficiency stand alone products and entering the period of high efficiency integrated systems.

Moving from simple products to large systems enables us to develop more efficient and flexible solutions, but leads to a higher level of complexity. Complexity increases for the building owner, who has to define the Owner's Project Requirements (OPR) in greater detail. It also increases for the designer who has to design and define a full system on the basis of a growing number of attractive components. Complexity increases for the installer who has to install large systems which are all different, often innovative and have complex control and complex interactions. Complexity increases for the users who have access to more and more choices for the operation of the building.

The management of this complexity requires new approaches, new skills and new tools. Most of these were not available 20 years ago and are not yet taught at school. Commissioning is one of the new approaches to manage the complexity of today's building and HVAC systems.

### Commissioning

Commissioning is done for the number of reasons: clarifying building system performance requirements set by the owner, auditing different judgments and actions by the commissioning related parties in order to realize the performance, writing necessary and sufficient documentation, and verifying that the system enables proper operation and maintenance through functional performance testing. Commissioning should be applied through the whole life cycle of the building. In the coming years, commissioning will probably develop for three main reasons:

- Energy and environment related reasons: Global warming has increased the pressure to reduce energy use in buildings.

- Business related reasons: Many companies are developing new services to diversify their activities in the building and energy industries. They see the commissioning as a way to develop new business for the benefit of their customers.

- Technological reasons: Building automation systems are now standard in new buildings and are being installed in many older ones. These systems automatically collect building and plant operating data and offer possibilities for innovative commissioning services.

The primary obstacles that impede the adoption of commissioning as a routine process for all buildings are clearly lack of awareness, lack of time, and too high costs. Hence, efforts for improvement should consider how new tools, methods and organizations can increase the awareness of commissioning, decrease the cost and demonstrate the benefits obtained by performing commissioning.
## 9.2 Definition of the Commissioning Process

Commissioning is a quality-oriented process for achieving, verifying, and documenting whether the performance of a building's systems and assemblies meet defined objectives and criteria.

Commissioning is too often viewed as a task performed to check operational performance after a building is constructed and before it is handed over to the building owner. A broader view was clearly favoured, which starts at the predesign phase, goes through the construction process, and continues during operation. This broader view aims at bridging the gaps among four different visions: the expectations of the building owner, the project of the designer, the assembled system of the contractor, and the running system of the operator. Bridging these gaps will consist in:

- clarifying the expectation of the building owner to obtain the owner's project requirements so that the owner and designer understand each other and are in agreement

- translating the project of the designer to specifications which can be understood and realized and verified by the contractor

- applying functional performance testing procedures which will enable the contractor the building owner and the designer to verify that the system is clearly operating as expected

- producing system manuals which will enable the operator to take the best profit of the ideas of the designers and of the system realized by the contractor to fulfill owner requirements

- producing reports at regular interval which will enable the operator and the building owner to check that the operation continues to fulfill these requirements

In this broader view, the Commissioning process begins at project inception during the predesign phase and continues for the life of the facility through the occupancy and operation phase. This global view aims at providing a uniform, integrated, and consistent approach for delivering and operating facilities that meet the on-going requirements of the owner. This broad view could appear to many users as a dream which could be realized in a few projects but which is too far from their day to day practice to be applicable to their projects. In practice, one can differentiate four types of commissioning which are represented in Figure 9-1:

- Initial Commissioning (I-Cx) is a systematic process applied to production of a new building and/or an installation of new systems.

- Retro-Commissioning (Retro-Cx) is the first time commissioning which is implemented in an existing building in which a documented commissioning process was not previously implemented.

- Re-Commissioning (Re-Cx) is a commissioning process implemented after I-Cx or Retro-Cx when the owner hopes to verify, improve and document the performance of building systems.

- On-Going Commissioning (On-Going Cx) is a commissioning process conducted continually for the purposes of maintaining, improving and optimizing the performance of building systems after I-Cx or Retro-Cx.
<figure><img src="image_156.png" /><figcaption>**Figure 9-1.** *The 4 different types of commissioning.*</figcaption></figure>

The building process from design to operation is described in relation to the HVAC commissioning activities.

<figure><img src="image_157.png" /><figcaption>**Figure 9-2.** *Different building processes.*</figcaption></figure>

### Pre-Design Phase

Pre-Design Phase is the first phase of the I-Cx process, divided into two steps, namely:

- Program Step

- Planning Step

### Program Step

The Owner's Program (OP) is established and the owner generates request for proposal and solicits a Cx-Authority (CA). At this stage, the owner can ask for inside and/or outside professionals for advice on technology, finance, business and construction.
### Planning Step

The appointment of the CA typically defines the beginning of the planning step. The CA consults the construction manager, facility manager, financial advisor, operation and maintenance staff, occupant, etc., to identify the systems targeted for Commissioning and documents. In addition, the CA will assist the owner and consultants in estimating costs for design, construction, Testing Adjusting & Balancing (TAB) and investigate the necessary regulations related to the Commissioning. The scope of the work varies widely depending on the project size and owner's requirements for Commissioning. But in general, for a successful Cx Process, the CA develops a commissioning plan and with the owner formulates the design requirements. The design requirement in conjunction with the owner's requirement is used to generate the Owner's Project Requirement (OPR). The OPR allows a design professional to propose a firm design. Consequently, an request for proposal is generated and used to select a design professional for the project.

### Design Phase

Design phase begins with drafting schematic planning documents and ends with completion of design documents and their handover to the owner and is divided into two steps, namely:

- Preliminary Design Step

- Working Design Step

#### Preliminary Design Step

The preliminary design step begins with schematic planning documents and ends with the submission of the preliminary design documents. The CA verifies that these documents are appropriate and clarifies the procedure and schedule of Commissioning. The CA coordinates the commissioning plan with the design intent so that the design professional can state the commissioning specification in the design documents.

#### Working Design Step

The final design documents are developed. The design professional updates the draft design intent document in the preliminary design documents and completes the final design documents. The CA audits these documents for completeness. The design is the responsibility of the design professional. Inconsistencies with the OPR, however, should be highlighted to the owner by the CA.

### Elaboration Phase

The elaboration phase is the transitional phase between completion of design and commencement of construction. In this period, the completion of the construction documents, bid submission, bid assessment and selection of the contractor for the construction is carried out. The CA helps to coordinate the commissioning related parties.

### Construction Phase

Includes construction, testing adjusting & balancing, Functional Performance Testing (FPT) and acceptance, under the guidance of the CA and is described in two steps:

- Construction Step

- Acceptance Step

#### Construction Step

Shop drawings are created from the design documents. Work is installed and testing adjusting & balancing is carried out. The CA conveys changes of OPR to the commissioning related parties or proposes design changes to ensure performance is achieved. The CA audits performance of the
construction supervision and control, and supervises the TAB work confirming the maintainability of building systems with the owner.

### Acceptance Step

The CA verifies the TAB work, the correctness of the as-built records and determines from FPT results whether the operations of the equipment and systems meet the OPR. Deficiencies are addressed by the appropriate party. The CA plans and manages the training program.

### Occupancy & Operation Phase

The occupancy and operation phase takes place after handover when the building systems are operating acceptably. Some seasonal FPT will still be required with certain systems. There are two steps:

- Post-Acceptance Step

- Ordinary Operation Step

### Post-Acceptance Step

The post-acceptance step applies to building systems in which the performance is seasonally changed and the design requirement demands confirmation of the annual performance (HVAC systems). This is the final step of the I-Cx process. The role of the CA in this step is to identify the seasonal system performance. This might include (for HVAC systems) determining the system performance for the peak-cooling season, the peak heating season, and the intermediate season when cooling and heating modes are both required. FPT is used in conjunction with the BEMS after faults identified in the acceptance step have been rectified. The term of the post-acceptance step mostly overlaps with the warranty term of the construction and the seasonal FPT mentioned above is considered to be requested in the range of the construction.

### Ordinary Operation Step

In the ordinary operation step, the evaluation work for the Re-Cx and/or On-Going Cx to identify the unresolved issues, desired changes, weaknesses identified, desirable improvements identified during Commissioning, warranty action items, etc., may be addressed. The repeated Re-Cx could correct faults and the evolution to the On-Going Cx may maintain the building systems in optimal condition through the life of the building.

## 9.3 The commissioning plan: A tool to structure the commissioning process

Whatever organization approach is chosen, the key challenge to commission a building or system is to follow a well managed process. A central document for that purpose is the Commissioning Plan which defines the actions to be performed.

The Commissioning Plan is the key tool that gives the different players an understanding of what is meant by commissioning on a specific project, what amount of effort and money will be required and how it will be managed. The global content of this Commissioning Plan will be defined at the beginning of the project and will be refined all along the project.

Three types of tools were used within the Annex to support the definition and application of the Commissioning Plan. The following table gives an overview of these three types of tools:
<table><caption>**Table 9-1. Tools used in commissioning plans.**</caption><thead><tr><td>Tool</td><td>Description</td><td>Level of detail</td></tr></thead><tbody><tr><td>Standard Models of Commissioning plans (SMCxP)</td><td>A typical description of commissioning actions during a project.<br>To be used as a guideline to define commissioning plan for a given project.</td><td>Medium</td></tr><tr><td>Checklists</td><td>Medium level of definition of a commissioning plan is specific to a given type of HVAC system.</td><td>low</td></tr><tr><td>Matrix for Quality Control (QMC)</td><td>An extensive tool for the management of the quality of the whole construction project.<br>Includes commissioning plan as well as other elements in a very structured way.</td><td>high</td></tr></tbody></table>

### 9.3.1 Standard model of commissioning plans

These standard models include typical lists of tasks with a description of the content of each task. They can be used as a basis to define customized Commissioning Plans adapted to a given project. Five standards models of Commissioning Plans are defined. The appropriate model can be selected by a risk evaluation which takes into account building size, HVAC system complexity and the accepted risk level.

#### Building size

The risk of malfunctions increases when one moves from small heated buildings to large air conditioned buildings.

#### HVAC system complexity

HVAC packaged units designed to perform multiple functions to meet specifications which have been selected for a given building. Distributed systems, such as hydronic heating system or centralized air conditioning systems, are connected through air or water networks to constitute unique systems. The risk of poor design and installation is clearly higher with distributed systems. Therefore, they require more intensive commissioning.

#### The accepted risk level

The accepted risk level depends on:

- The building owner and operator strategy: When the future user of the building is involved in the project from the beginning, the approach chosen to look at future operation of the building is often much more detailed. So, the effort put in commissioning can be much more intensive.

- Criticality of building operation: Laboratories, computer centers, industrial and headquarter buildings are examples of buildings where malfunction may have high economic or image impacts. In such buildings the commissioning effort can also be more intensive than in other buildings.

### 9.3.2 Checklist

The minimum version of a Commissioning Plan is a checklist defining the verifications to be performed as the project progresses to ensure that critical actions were effectively performed. The key advantage of the checklist is its simplicity. There would be no need to use a special software or for in-depth training of the users. The main disadvantage is that it defines what to do but not how to do it and does not include a documentation of the results obtained.
In simple projects, where an independent commissioning authority generally will not be involved, the checklist enables the project manager to apply a minimum of quality control. Checkpoints are especially important when proceeding from one project phase to the next. These checklists will be used by each party involved in the project.

### 9.3.3 Matrix for quality control

Matrix for Quality Control (MQC) was initially developed in the Netherlands as a tool for the overall quality control of climate control Climate Installations. In the Netherlands, the MQC structure has been elaborated for heating systems and domestic ventilation systems. Its intention is to control the total production process including specifications, design, construction, hand-over and operation. It focuses on avoiding failures on all strategic aspects and phases in this process.

The most important characteristic of MQC for HVAC systems is a structure that follows through all the process phases. This enables planners to build in a number of strategic decision points in the building and system process and to assess if a system meets the targets and requirements, as defined in the program phase. The total quality required is determined by several aspects (not only technical but also financial, organisational and communications).

This leads to a so-called quality control matrix. On the horizontal axis of the matrix, the phases of the process are presented. On the vertical axis of the matrix, quality control elements are listed.

## 9.4 How to execute the commissioning plan

The commissioning plan defines a list of tasks to achieve, verify and document the performance of the building. Users need some tools to be able to perform tasks defined in the commissioning plan. Annex 40 identified three types of tools to perform these kinds of tasks. These three tasks are listed below:

- Functional performance testing (FTP)

- Using the building control system for commissioning

- Using models at the component level

### 9.4.1 Functional performance testing (FTP)

Many actors around the world have already developed some performance procedures. The main challenges today consists in making the best use of existing procedures adapted to national building industry and contract standards, and only develop new ones when required.

IEA Annex 40 (IEA 2001) strategy consisted in specifying the commissioning process and the tools actually required for the application of each commissioning plan, in addition to transferring existing procedures from one country to another one and in developing new required procedures. The main information sources were localized, among them in US, where an important data base is available. This source was very much used in the frame of IEA Annex 40. Each component has a well defined function inside the whole HVAC system. Any malfunction can compromise the correct behaviour of the whole system. The malfunction may occur due to:

- Design faults

- Selection or sizing mistakes

- Manufacturing fault or initial deterioration

- Installation faults

- Wrong tuning

- Control failure
— Abnormal conditions of use.

The FPT is devoted to the detection of such possible malfunction and to its diagnosis. The test can be active or passive, according to the way of analyzing the component behaviour i.e. with or without artificial perturbation. Active tests are mostly applied in initial commissioning, i.e. at the end of the building construction phase. Later in the Building Life Cycle (BLC), i.e. in re-, retro- and on-going commissioning, a passive approach is usually preferred, in order to preserve health and comfort conditions inside all the building occupancy zones. A generic description of a FPT includes:

— A description of the system, subsystem or component considered

— A presentation of the testing procedure

— Some additional possibilities (model use and possibility of automation

FPT can be realized on the whole system, a subsystem (several interconnected components) or on specific components that are considered as critical. The selection of the appropriate level is made on the basis of risk in relation with the acceptance criteria. The search for malfunctions can either follow a top-down or bottom-up route:

### Top-down

The whole system functional performances are first verified, moving on to subsystems and then onto specific components as malfunctions are found and require investigation. The goal is not to verify if a component is good or bad in itself, but to check if it's correctly integrated in the system considered.

One problem is the possibility that energy-wasting situations could be missed. For example, a poorly-tuned control may cause an air handling unit to cycle between heating and cooling. If the zone temperature doesn't vary too much and stays very near to its set point, the problem might not be apparent. Such faults may be found at the system level only, if the losses are great enough to be obvious when compared with expectations.

### Bottom-up

Starts by confirming the performance of an elementary component and progressively working up to the whole system. This may be more appropriate for initial commissioning, following construction. It allows a safer identification of local defaults, but it may require excessive effort.

### 9.4.2 Using the building control system for commissioning

Today, microprocessor-based control systems are used to automatically operate many of the major energy systems in buildings. As technology continues to evolve, the trend is for more systems to come under the action of automatic control and for disparate systems to be integrated across communication networks. Automatic control systems eliminate the need for dedicated manual operators and can reduce costs. Modern control systems also allow the operation of multiple energy systems to be coordinated according to advanced building-level strategies. The proliferation of automation in buildings has led to a situation in which realizable building performance is fundamentally dependent on the control system. An important part of commissioning should therefore be to ensure that the control system is operating properly.

It is useful at this point to define what components constitute the building control system. First, it is assumed that the control system encompasses both hardware and software. On the hardware side, the scope of definition is limited to the components such as sensors, actuators, wiring, switches, and (microprocessor-based) control devices. The boundary for the hardware side is, therefore, the point
of interface to the energy systems and the controlled environment. Scope on the software side is limited to the control algorithms, user interface, and other miscellaneous functionality that is typically packaged in modern systems. Control systems are becoming more modular and, from a commissioning perspective, modularization helps to move some of the onuses of testing onto the factory and component vendor. A valid expectation is therefore that components, whether hardware or software, have been tested before arriving at a building for installation. The most important aspects then to verify and commission on-site will be those that have been affected by the installation process. For example, checking wiring and panel connections is very important as is verifying that all on-site software downloads and/or configurations have been successful. Pre-calibrated sensors are reducing the need for wide-scale sensor validation but an important and related commissioning task is to check whether sensor points have been correctly mapped into the control logic.

In addition to commissioning the control system itself, the control system can also be used as a tool for carrying out commissioning on the energy systems. A control system can serve as a commissioning tool by making use of its ability to manipulate energy systems through interfaces such as actuators and switches. The idea is to carry out tests that involve making changes to a particular system through the control system rather than by direct manipulation. Sensors connected to the control system allow the effects of changes to be measured and recorded. Different levels of automation can be applied when using the control system as a commissioning tool. A human operator can perform tests through a user-interface portal or test procedures can be programmed into the control system and be activated by a user. Varying degrees of automation can also be employed in the analysis of test results.

### 9.4.3 Using models at the component level

The following steps comprise a *use case* for a general purpose, component-level, and model based commissioning tool that can be used both for initial commissioning and for performance monitoring during routine operation:

- For automated functional performance testing, the model is configured using manufacturers' performance data and system design information. In general, the model parameters will be determined by a combination of direct calculation and regression.

- An active test is performed to verify that the performance of the component is acceptably close to the expected performance. This test involves forcing the equipment to operate at a series of selected operating points specifically chosen to verify particular aspects of performance (e.g. capacity, leakage).

- The test results are analyzed, preferably in real time, to detect and, if possible, to diagnose faults.

- If necessary, the test is performed again to confirm that any faults that resulted in unacceptable performance have been fixed. Once the results of this test are deemed acceptable, they are taken to define correct (i.e. acceptable) operation.

- The model is re-calibrated using the acceptable test results.

- The tool is used to monitor performance during on-going operation. This will typically be done in passive mode, though active testing could be performed at particular times, e.g. every weekend, after routine maintenance, after system modifications or retrofit, on change of ownership, etc.
## 9.5 Applying commissioning process to the lighting control system

The aim of the commissioning applied to the lighting control system is to verify if the performance of this system meet the defined performance and criteria. The first step consists of collecting the performance targets of the system and defining the criteria to assess these performance.

### 9.5.1 Objectives of lighting systems

Adequate and appropriate lighting should be provided so that people are able to perform visual tasks efficiently and accurately. The illumination can be provided by daylight, artificial lighting or a combination of both. The level of illuminance and comfort required in a wide range of work places is governed by the type and duration of activity.

### 9.5.2 Criteria for lighting systems quality

For good lighting practice, it is essential that the qualitative and quantitative needs are satisfied in addition to the required illuminance. Lighting requirements are determined by the satisfaction of three basic human needs:

- Visual comfort which enables the workers to have a feeling of well-being (in an indirect way) also contributing to a high productivity level

- Visual performance which enables the workers to perform their visual tasks, even under difficult circumstances and during longer periods with comfort.

- Safety

Main parameters determining the luminous environment are:

- Luminance distribution

- Illuminance

- Glare

- Directionality of light

- Color rendering and color appearance of the light

- Flicker and stroboscopic effects

- Maintenance factor

- Energy considerations

- Daylight

Methods of calculation of all these parameters are available in the European standard EN 15251.

### 9.5.3 Indicators to evaluate the performance of lighting system

Previous paragraph defines a list of criteria for lighting system. Some indicators are necessary to evaluate these criteria.

#### Luminance distribution

The luminance distribution in the field of view controls the adaptation level of the eyes which affects task visibility. A well balanced adaptation luminance is needed to increase:

- Visual acuity (sharpness of vision)

- Contrast sensitivity (discrimination of small relative luminance differences)

- Efficiency of the ocular functions (such as accommodation, convergence, pupil contraction, eye movements etc.)
The luminance distribution in the field of view also affects visual comfort. The following situations should be avoided for the reasons given:

- Too high luminances which may give rise to glare

- Too high luminance contrasts which will cause fatigue because of constant re-adaptation of the eyes

- Too low luminances and too low luminance contrasts which result in a dull and non-stimulating working environment

## Illuminance

The illuminance and its distribution on the task area and the surrounding area have a great impact on how quickly, safely and comfortably a person perceives and carries out the visual task. All values of illuminances specified in the European standard EN 12464 are maintained illuminances and will provide for visual comfort and performance needs.

## Glare

Glare is the sensation produced by bright areas within the field of view and may be experienced either as discomfort glare or disability glare. Glare caused by reflections in specular surfaces is usually known as veiling reflections or reflected glare. It is important to limit the glare to avoid errors, fatigue and accidents. In interior work places, discomfort glare may arise directly from bright luminaires or windows. If discomfort glare limits are met, disability glare is not usually a major problem.

## Directionality of light

Directional lighting may be used to highlight objects, reveal texture and improve the appearance of people within the space. This is described by the term modelling. Directional lighting of a visual task may also affect its visibility.

## Color aspects

The color qualities of a near-white lamp are characterised by two attributes:

- The color appearance of the lamp itself,

- Its color rendering capabilities, which affect the color appearance of objects and persons illuminated by the lamp.

These two attributes shall be considered separately

## Flicker

Flicker causes distraction and may give rise to physiological effects such as headaches. Stroboscopic effects can lead to dangerous situations by changing the perceived motion of rotating or reciprocating machinery. Lighting systems should be designed to avoid flicker and stroboscopic effects.

## Maintenance factor

The lighting scheme should be designed with an overall maintenance factor calculated for the selected lighting equipment, space environment and specified maintenance schedule. The recommended illuminance level for each task is given as maintained illuminance. The maintenance factor depends on the maintenance characteristics of the lamp and control gear, the luminaire, the environment and the maintenance programme. The designer shall:
- state the maintenance factor and list all assumptions made in the derivation of the value

- specify lighting equipment suitable for the application environment

- prepare a comprehensive maintenance schedule to include frequency of lamp replacement, luminaire and room cleaning intervals and cleaning method.

## Energy considerations

A lighting installation should meet the lighting requirements of a particular space without waste of energy. However, it is important not to compromise the visual aspects of a lighting installation simply to reduce energy consumption. This requires the consideration of appropriate lighting systems, equipment, controls and the use of available daylight.

## Daylight

Daylight may provide all or part of the lighting for visual tasks. It varies in level and spectral composition with time and thus provides variability within an interior. Daylight may create a specific modelling and luminance distribution due to its nearly horizontal flow of light from side windows. Windows may provide visual contact with the outside environment, which is preferred by most people.

In interiors with side windows, the amount of available daylight decreases rapidly with the distance from the window. Supplementary lighting is needed to ensure the required illuminance level at the work place and to balance the luminance distribution within the room. Automatic or manual switching and/or dimming may be used to ensure appropriate integration between electric lighting and daylight. To reduce glare from windows, screening should be provided where appropriate.

## 9.6 Example of a Commissioning Plan applied to the lighting system

The purpose of the commissioning plan is to provide direction for the commissioning process during the life cycle of the building. It provides resolution for issues such as scheduling, roles and responsibilities, lines of communication and reporting, approvals, and coordination.

The commissioning plan defined at each step of the process the list of tasks to perform to assess the performance of the system. Associated tools could be also associated to help the commissioning provider to perform tasks. Tasks defined in the commissioning plan could be shared in two parts, namely; organisational part and technical part. The commissioning plan could also provide a general description of the commissioning team in order to identify persons relevant to the commissioning process.

The objective is to be able to contact the right person in case of malfunctioning of buildings or systems of the building. Each related actors should be identified by his name, address, phone number and e-mail address.
<table><caption>Figure 9-3. Tasks of the Commissioning plan for lighting systems.</caption><tbody><tr><td rowspan="2">Program step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that the list of the relevant to take into account has been defined.</td></tr><tr><td rowspan="2">Working design step</td><td><strong>Cx Technical</strong></td></tr><tr><td>Check that the occupant's lighting needs (Lighting requirement and calculation & lighting zone assumptions) have been defined.<br>Check that the energy performance of the lighting system has been defined.</td></tr><tr><td rowspan="2">Elaboration step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that the lighting system control method is defined.<br>Check that each room has its own control system.<br>Check that each local, luminaires of the row closet to the windows could be controlled separately.<br>Check that the designer specified lighting equipment are suitable for the application environment.<br><br><strong>Cx Technical</strong></td></tr><tr><td rowspan="2">Construction step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that the plans of the offer answer the initial requirements.<br>Check that the hypotheses of calculation are justified.<br>Check that plans take into account the location of the components of the installation.<br>Check that the plans take into account the accesses allowing the maintenance.<br>Check that the list of the tests and controls is included in the answer to the offer.<br><br><strong>Cx Technical</strong></td></tr><tr><td rowspan="2">Acceptance step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that lighting systems control is well connected.<br>Check that schedule of the lighting system is implemented into the building energy management system.<br>For sweep-off system, check that appropriate start and stop times are set to accommodate weekdays, weekends and holidays operation.<br>For daylight-linked system be sure all furnishings and interior surface materials are installed before calibration.<br>For manual dimming, check that the dimmer has been installed in correct position adjacent to the wall switch as par drawings</td></tr><tr><td rowspan="2">Post acceptance step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Provide building maintenance personnel with all necessary documentation and operation instructions to re-commission and maintain the system.<br>Check that a user's guide has been written.<br>Check the periodicity of the maintenance's inspection.<br><br><strong>Cx Technical</strong></td></tr><tr><td rowspan="2">Post post-acceptance step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that placements and orientation of the sensors are correct according to the plans.<br>Check that the sensitivity of the occupancy sensor is adjusted.<br>Check that the time delay of the occupancy sensor is adjusted according to the room.<br>Check that the schedule of the lighting system meets the effective functioning of the lighting system.<br>Check that local and/or central overrides are well taken into account.<br>Check that the lighting system is well controlled.<br>For dimming system, check that burn in new lamps by operating the lamps at full power continuously for 100 hours.<br>For daylight-linked system, check that the light sensor is calibrated in order to obtain desired light level at the work surface.<br><br><strong>Cx Organizational</strong></td></tr><tr><td rowspan="2">Post acceptance step</td><td><strong>Cx Technical</strong></td></tr><tr><td>Inform occupants about the functionality of the controls and, particularly, the overrides.<br><br><strong>Cx Organizational</strong></td></tr><tr><td rowspan="2">Post post-acceptance step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that the performance of lighting equipments is yearly evaluated.<br>Check that the sensors are yearly cleaned up (every six months for outside sensors).<br><br><strong>Cx Technical</strong></td></tr><tr><td rowspan="2">Post post-acceptance step</td><td><strong>Cx Organizational</strong></td></tr><tr><td>Check that the re-calibration of the sensors is done if the environment of the building has changed (construction of the new building, for example)<br>In the case of modification of the zone destination, check that scheduling defined in the building energy management system still corresponds to the zone.</td></tr></tbody></table>
## References

IEA, 2001. IEA Annex 40 - Commissioning of Building HVAC Systems for Improving Energy Performance, website http://www.ecbcs.org/annexes/annex40.htm

IEA, 2004. IEA Annex 31 report: Environmental framework, IEA ECBCS 2004, 24 pp.

IEA, 2000. IEA SHC Task 21/ Annex 29 report: Design guidelines-Daylighting guidelines, July 2000.

ANSI/ASHRAE, 2002. ANSI/ASRAE Standard 135-2001: A data communication protocol for building management and control networks (BACnet specification), April 2002.

DALI, 2004a. Digital Addressable Lighting Interface (DALI) control devices protocol part 1-2004, general requirements, draft version 1.13, 29-10-2004, NEMA standard publication.

DALI, 2004b. Digital Addressable Lighting Interface (DALI) control devices protocol part 2-2004, specific commands for control devices, draft-version 1.13, 29-10-2004, NEMA standard publication.

Jennings et al., 2000. Comparison of control options in private offices in an advanced lighting controls testbed. Journal of the Illuminating Engineering Society 2000; p 39-60.

E Source, 2004. Design briefs: Lighting control, Energy design resources, report published on 2 March 2004, available at: http://www.energydesignresources.com.

The Watt Stopper. Lighting control best practice guide: Office buildings, available at http://www.wattstopper.com.

New buildings institute, 2003. Advanced lighting guidelines: 2003 edition, New buildings institute Inc, available at http://www.newbuildings.org/lighting.htm.

Bierman A, Morante P, 2003. Lighting controls- where we are and where are we going, presentation to association of energy services professionals 14th national energy service conference and exposition, December 9, 2003, Lighting Research Centre/ Rensselaer Polytechnic Institute.

Peter Morante, 2005. Reducing barriers to the use of high-efficiency lighting systems, technical report, Rensselaer Polytechnic Institute, 2005.

California energy commission, 1999. Lighting efficiency technology report: Volume I – California baseline, Volume II – Scenarios, Volume III – Market barriers report, Volume IV – Recommendations report, California energy commission, P400-98-004VI.

Mistrick et al., 1999. An analysis of photosensor-controlled dimming systems in a small office, Illuminating engineering society of North America 1999 annual conference proceedings, IESNA, New York, pp 433-448.

Viljanen, T., Halonen, L., Lehtovaara, J., Advanced lighting control technologies for user satisfaction and energy efficiency, Proceedings of Right Light 4, Vol. 1. 19-21.11. 1997.

Rubinstein, F., Treado, S., Pettler, P., 2003. Standardizing communication between lighting control devices: a role for IEEE P1451, in proceedings of IEEE Industry Applications Conference, Oct 2003, volume 2, p 805-811.

ENOCEAN, 2007. Enocean home page, 2007, http://www.enocean.de.
# Chapter 10: Case studies

## Topics covered

<table><tr><td>10</td><td>Case studies</td><td>247</td></tr><tr><td>10.1</td><td>Introduction and main results</td><td>247</td></tr><tr><td>10.2</td><td>Case study 1: Optimizing of daylighting and artificial lighting in offices</td><td>248</td></tr><tr><td>10.3</td><td>Case Study 2: Offices of a Finnish research unit</td><td>250</td></tr><tr><td>10.4</td><td>Case Study 3: Renovation of a German bank</td><td>260</td></tr><tr><td>10.5</td><td>Case study 4: High lighting quality targets with minimum electric power density</td><td>265</td></tr><tr><td>10.6</td><td>Case Study 5: Renovation of a cultural centre</td><td>271</td></tr><tr><td>10.7</td><td>Case study 6: Sture Library in Stockholm fully lit by LED lighting</td><td>272</td></tr><tr><td>10.8</td><td>Case study 7: Town hall in Stockholm</td><td>273</td></tr><tr><td>10.9</td><td>Case study 8: Turning Torso</td><td>274</td></tr><tr><td>10.10</td><td>Case study 9: Comparison of LED and fluorescent lighting in a meeting room</td><td>275</td></tr><tr><td>10.11</td><td>Case study 10: Factory in Netherlands</td><td>279</td></tr><tr><td>10.12</td><td>Case study 11: Factory in Italy</td><td>282</td></tr><tr><td>10.13</td><td>Case study 12: School - lighting refurbishment</td><td>285</td></tr><tr><td>10.14</td><td>Case study 13: School - bright classroom</td><td>289</td></tr><tr><td>10.15</td><td>Case study 14: Primary school - bright classroom</td><td>292</td></tr><tr><td>10.16</td><td>Case study 15: Primary school Beveren-Leie - lighting refurbishment</td><td>294</td></tr><tr><td>10.17</td><td>Case study 16: High school of St Eligius - lighting refurbishment</td><td>296</td></tr><tr><td>10.18</td><td>Case study 17: Primary School in Roma (1)</td><td>298</td></tr><tr><td>10.19</td><td>Case study 18: Primary School in Roma (2)</td><td>301</td></tr><tr><td>10.20</td><td>Case Study 19: Energy saving potential in the University</td><td>304</td></tr><tr><td>10.21</td><td>Case Study 20: Renovation of an auditorium</td><td>307</td></tr><tr><td>10.22</td><td>Case Study 21: Replacement of metal halide lamp by induction lamp</td><td>309</td></tr><tr><td>10-23</td><td>Appendix 1. Data list for case studies</td><td>312</td></tr></table>
# 10 Case studies

## 10.1 Introduction and main results

Case studies of different types of lighting systems were conducted. The studies were conducted for a variety of buildings (most of them being office buildings and schools) in different locations around Europe. The main results of the case studies are summarised briefly in the following, Appendix 1 shows the data list for the case studies.

In office buildings, different case studies showed that it is possible to obtain both good visual quality and low installed power for lighting. It is possible to reach the normalized power density of 2 W/m².100 lx (even 1.5 W/m².100 lx in some cases) with the current technology. The studies also indicated that the best performance is reached in the office environment when the luminaries are shared between at least two persons. Development of LED technology is growing and the case studies show that the technology is already well suited in the task lighting applications.

Application of lighting control devices is another important aspect of improving the energy efficiency of the lighting system. It was found that the use of lighting control system to switch the lights on and off based on occupancy sensors can reduce the lighting energy intensity of office buildings. Additionally the use of dimming and control sensors for the integration of daylight and artificial light can yield further energy savings. However, the design of the lighting system has to be made carefully, so that the user can control and choose the visual environment of his/her choice. Allowing individual control of lighting enables the technology to be accepted by the users, as the lighting needs of people are different. Uniformity and Glare have effect on acceptability of the lighting system. Uniformity of 0.6 is found to be acceptable in several case studies. Occupants also give importance on controlling the luminances of the light sources in the field of view of the workers.

The case studies in factories indicated that general lighting can be reduced by employing task lighting and individual control of the task lighting combined with automatic control of general lighting according to the working hours. This can yield to increases in productivity (due to better lighting) and to decreases in the lighting energy consumption. It is also possible to use dimming according to daylight in the factories. In one factory case the dimming according to daylight could save about 50% of the energy used for lighting. The study showed that the normalized power density of 2.78 W/m².100 lx can be reached.

The case studies in schools indicate that it is possible to reach the normalized power density of 2 W/m².100 lx with the application of current technology, including the recommended black-board lighting. Refurbishment of the old installations with new technology is an attractive option to improve the energy efficiency in schools. One of the major problems related to the use of daylight in schools is the sunlight coming through the windows and falling on the work planes, blackboards etc. Design of daylight utilisation system must guarantee a total protection against glare from the sun. Otherwise people can move their desks or shade all the daylight with the blinds.
## 10.2 Case study 1: Optimizing of daylighting and artificial lighting in offices

- Place: Switzerland (Lausanne)

- Building type: Office building

- Contact: F. Linhart (LESO, Ecole Polytechnique Fédérale de Lausanne)

### Place description

<figure><img src="image_158.png" /><figcaption>**Figure 10-1.** *Southern façade of the building and a cross section from the façade's system.*</figcaption></figure>

A mirror redirects daylight from the sky to the diffuse room ceiling, which reflects the light into the room. Daylight is guided towards the ceiling by a mirror, in order to be forwarded to the parts further away from the window. The system increases the daylight entering to the rear of the room and helps to reduce glare near the window section. Moreover, the windows are built with outside blinds.

<figure><img src="image_159.png" /><figcaption>**Figure 10-2.** *Office plan with luminaries position.*</figcaption></figure>

The office room is used by two people. Work plane height is 0.8m.
## Luminaries description

<figure><img src="image_160.png" /><figcaption>Figure 10-3. Characteristics of the luminaires.</figcaption></figure>

**Luminaires:** Ceiling mounted luminaire LIP from REGENT, reflector with prismatic diffusion upon the longitudinal axis, and specular batwing upon the transverse axis (luminaire Light Output Ratio 69%).

**Lamp:** Sylvania T8 36W lamp ($R_a$ > 80, CCT = 3000K, luminous flux = 3350 lm).

**Ballast:** Philips HFR 136 TLD 220-240 dimmable 0V-10V, announced power factor = 0.95

**Price of the luminaire in catalogue** = 250€

The control has been placed at the entrance of the office; people can operate it according to their needs.

The lighting power density is 4.5W/m².

## Measurements

Illuminance measurements (artificial lighting only) on the work plane at maximum power for lighting:

$E_{average}$ = 235 lx

$E_{max}$ = 308 lx

$E_{min}$ = 186 lx

Uniformity = 0.79

## Occupant's satisfaction

Six people have been working in this office over two years. All workers expressed that they were satisfied with their lighting conditions.

Views of the six office-workers:

- The light in my office is generally comfortable: 83% agree

- Artificial lighting in my office is able to provide enough light: 83% agree

- The facilities which are in my office (windows, blinds, artificial and day-light systems) make me able to get every time a right lighting situation, so I can work in good conditions: 83% agree.

- With only artificial light, no remarks were mentioned about a too cold or too hot feeling.
## 10.3 Case Study 2: Offices of a Finnish research unit

* Place: Finland (Helsinki)

* Building type: Office building

* Contact: Eino Tetri (Helsinki University of Technology, Lighting Unit)

### Place description

<figure><img src="image_161.png" /><figcaption>**Figure 10-4.** *Photos of the office rooms.*</figcaption></figure>
Offices Plan

<figure><img src="image_162.png" /><figcaption>**Figure 10-5.** Office Plan with the luminaries position.</figcaption></figure>

The average installed lighting power density is 13.86 W/m². The ceiling height varies between 2.26 m and 2.94 m. The installation height of the luminaires is 2.26 m and height of the work plane is 0.72 m. Each office room has daylight availability. The rooms are used between 7 am and 5:30 pm except weekends. Cleaning of the rooms is made at noon.
## Luminaries description

FUTURO 672TPH 3xTL5-28W 830 HFP M2

<figure><img src="image_163.png" /></figure>

a

<figure><img src="image_164.png" /><figcaption>a) Photometry of the luminaire b) Geometry of the luminaire</figcaption></figure>

Luminaire type N°1

<figure><img src="image_165.png" /></figure>

<table><thead><tr><th>W</th><th>W</th><th>A</th><th>B</th></tr></thead><tbody><tr><td>672TPH</td><td>3*TL5 28W</td><td>1200</td><td>1296</td></tr><tr><td>672TPH</td><td>3*TL5 35W</td><td>1500</td><td>1596</td></tr></tbody></table>

b

<figure><img src="image_166.png" /></figure>

a

<figure><img src="image_167.png" /></figure>

b

<caption>a) Luminaire ON b) Luminaire OFF</caption>

FUTURO 672TPH 3xTL5-35W 830 HFP M2

<figure><img src="image_168.png" /></figure>

a

<figure><img src="image_169.png" /><figcaption>a) Photometry of the luminaire b) Geometry of the luminaire</figcaption></figure>

Luminaire type N°2

<figure><img src="image_170.png" /></figure>

<table><thead><tr><th>W</th><th>W</th><th>A</th><th>B</th></tr></thead><tbody><tr><td>672TPH</td><td>3*TL5 28W</td><td>1200</td><td>1296</td></tr><tr><td>672TPH</td><td>3*TL5 35W</td><td>1500</td><td>1596</td></tr></tbody></table>

b
LUMENA 243TCS 2xTL5-35W HFR D6

<figure><img src="image_171.png" /><figcaption>Photometry of the luminaire</figcaption></figure>

<figure><img src="image_172.png" /></figure>

<figure><img src="image_173.png" /></figure>

<table><thead><tr><th></th><th>A</th><th>B</th></tr></thead><tbody><tr><td>243TCS, 244 TCS</td><td>28W</td><td>1000</td><td>1206</td></tr><tr><td>243TCS, 244 TCS</td><td>35W</td><td>49W</td><td>1506</td></tr></tbody></table>

<figure><img src="image_174.png" /><figcaption>Geometry of the luminaire</figcaption></figure>

Luminaire type N°3

<figure><img src="image_175.png" /></figure>

a

<figure><img src="image_176.png" /><figcaption>a) Luminaire ON b) Luminaire OFF</figcaption></figure>

b

POINT POINT Q 374FBH 1xPL-C 4P18W HFP

<figure><img src="image_177.png" /></figure>

374FBH, 200 mm

<figure><img src="image_178.png" /></figure>

a

<caption>a) Photometry of the luminaire b) Geometry of the luminaire</caption>

b

<figure><img src="image_179.png" /></figure>

a

<figure><img src="image_180.png" /><figcaption>a) Luminaire ON b) Luminaire OFF</figcaption></figure>

b

Luminaire type N°4
<figure><img src="image_181.png" /></figure>

Luminaire type N°5

<table><thead><tr><th></th><th></th><th>A</th><th>B</th><th>C</th><th>D</th><th>E</th><th>F</th></tr></thead><tbody><tr><td>402CWH</td><td>11W</td><td>350</td><td>52,5</td><td>223,5</td><td>74</td><td>187,5</td><td>88,5</td></tr><tr><td>402CWH</td><td>15W</td><td>542</td><td>58</td><td>426</td><td>58</td><td>271</td><td>213</td></tr><tr><td>402CWH</td><td>18W</td><td>695</td><td>98,5</td><td>498</td><td>98,5</td><td>347,5</td><td>249</td></tr><tr><td>402CWH</td><td>36W</td><td>1305</td><td>218,5</td><td>868</td><td>218,5</td><td>652,5</td><td>434</td></tr></tbody></table>

Geometry of the luminaire

<figure><img src="image_182.png" /></figure>

a

<figure><img src="image_183.png" /></figure>

b

a) Luminaire ON b) Luminaire OFF

WALL-MOUNTED KITCHEN LUMINAIRE

<figure><img src="image_184.png" /></figure>

a

<figure><img src="image_185.png" /></figure>

b

a) Luminaire ON b) Luminaire OFF

Luminaire type N°6

Luminaire type N°7

<caption>Figure 10-6. Luminaries characteristics (photometry, geometry, pictures).</caption>
Types of control

<figure><img src="image_186.png" /><figcaption>Figure 10-7. Type of control in Room G435.</figcaption></figure>

<figure><img src="image_187.png" /><figcaption>Figure 10-8. Type of control in Rooms G436 and G437.</figcaption></figure>

<figure><img src="image_188.png" /><figcaption>Figure 10-9. Type of control in Rooms G438 and G441.</figcaption></figure>
## Measurements

The average illuminances on work planes at full power

Inside the offices rooms:

<table><caption>**Table 10-1.** Illuminances on work planes in the office rooms.</caption><thead><tr><th></th><th>G435</th><th>G436</th><th>G437</th><th>G438</th><th>G439</th><th>G440</th><th>G441</th></tr></thead><tbody><tr><th>E<sub>average</sub> (lx)</th><td>588</td><td>671</td><td>610</td><td>728</td><td>723</td><td>716</td><td>806</td></tr><tr><th>Uniformity</th><td>0.71</td><td>0.78</td><td>0.64</td><td>0.71</td><td>0.80</td><td>0.69</td><td>0.65</td></tr></tbody></table>

In the Hall:

$$E_{\text{average}} = 293 \text{ lx, Uniformity} = 0.40$$

In the kitchen:

$$E_{\text{average}} = 177 \text{ lx, Uniformity} = 0.92$$

In the toilet room:

$$E_{\text{average}} = 337 \text{ lx, Uniformity} = 0.82$$

Illuminances on the work planes of the three rooms lowered (use of dimming control) by their occupants

Room G436:

$$E_{\text{average}} = 545 \text{ lx (80\%), Uniformity} = 0.7$$

Room G437:

$$E_{\text{average}} = 448 \text{ lx (73\%), Uniformity} = 0.57$$

Room G440:

$$E_{\text{average}} = 586 \text{ lx (80\%), Uniformity} = 0.77$$

## Measured luminances:

Luminances in the field of vision for the different positions in the office rooms reached 20000 cd/m². The UGR, depending on the positions, varied between 5.7 and 19.2

In the hall, the maximum luminance in the field of vision was 50 000 cd/m².

Ratios of the average luminances of work planes, walls, ceilings and, floor to desktop screen luminances are given in Table 10.2.
<table><caption>**Table 10-2. Ratio of the average luminances to desktop screen luminances.**</caption><thead><tr><td>Room</td><td>Position</td><td>Work planes</td><td>Walls</td><td>Ceiling</td><td>Floor</td></tr></thead><tbody><tr><td>G436</td><td>1</td><td>0.4</td><td>0.9</td><td>1.5</td><td>0.35</td></tr><tr><td>G436</td><td>2</td><td>1.3</td><td>1.84</td><td>3.3</td><td>0.77</td></tr><tr><td>G437</td><td>1</td><td>0.54</td><td>0.65</td><td>1.52</td><td>0.36</td></tr><tr><td>G437</td><td>2</td><td>1.1</td><td>1.6</td><td>3</td><td>0.72</td></tr></tbody></table>

### Example of power consumption in the offices during one day

In Figure 10-10, room G435 is user controlled and room G437 is controlled by occupancy and daylight sensors.

<figure><img src="image_189.png" /><figcaption>**Figure 10-10 Sample of power consumption in the offices during the day.**</figcaption></figure>

<figure><img src="image_190.png" /><figcaption>**Figure 10-11. Profile of the total power consumption of the locales during 7 days.**</figcaption></figure>

### Relationship between illuminance and consumed power in the offices
For all the rooms, the average annual energy consumption was 28kWh/m²year, whereas the average in Finnish buildings is 31kWh/m²year.

<figure><img src="image_191.png" /><figcaption>**Figure 10-12.** Relationship between illuminance and consumed power in the offices.</figcaption></figure>

## Interviews

The occupants of the office rooms were interviewed to examine their preferences for the installed lighting system. The occupants were all right-handed people with 56% of them having glasses. About 75% of the occupant's work time was spent working on computer screens. The result of the interview is listed below:

* 19% of the people say they suffer from headache at the end of the workday

* 6% of the occupants are not satisfied with their workspace.

* All appreciate the colour of the artificial light (3000K).

* Nobody is unhappy with the artificial lighting environment.

* 56% of the occupants never change the settings of the lighting control system whereas 25% of them change it weekly.

Room 435-- LON system with dimmer:

* 25% of user asked for improvements in lighting for the reading-writing tasks

* No negative opinions about computer work or other tasks

* Some occupants were not fully satisfied with the lighting control system

Rooms 438-441 -- DIGIDIM System (presence sensors):

* No negative opinion for the reading-writing tasks.

* No negative opinion for computer working or other tasks.

* 14% of the occupants were not fully satisfied with the lighting control system.
Rooms 436-437-- MIMO-LON system (presence sensors and daylight):

* Great comfort for the reading-writing tasks

* No negative opinion for the screen working or other tasks

* 40% of the occupants were not fully satisfied with the lighting control system
## 10.4 Case Study 3: Renovation of a German bank

- Place: Germany (Berlin)

- Building type: Office building

- Contact: W. Pohl (BartenBach, Innsbruck, Austria)

### Place description

Office building of KfW (Kreditanstalt für Wiederaufbau) (2001):

<figure><img src="image_192.png" /><figcaption>**Figure 10-13.** *View from outside to the south façade.*</figcaption></figure>

<figure><img src="image_193.png" /><figcaption>**Figure 10-14.** *Position /orientation of the building.*</figcaption></figure>

The height of the room is 3.4 m and the working desk height is 0.75 m. LON-controlled daylight system was used with high specular movable lamellas for daylight utilisation and sun shading.

<figure><img src="image_194.png" /><figcaption>**Figure 10-15.** *Views from inside (south facade).*</figcaption></figure>
## Description of the lighting systems

### Lighting system for general illumination with illuminance of 100 lx

- Compact fluorescent Dulux L 55W 840, electronic ballast, not dimmable

- CCT= 4000 K, R<sub>a</sub>= 80

- Total power consumption including ballast = 62 W

- LON/individual-controlled

<figure><img src="image_195.png" /><figcaption>Figure 10-16. Luminaires installation.</figcaption></figure>
### Lighting system for task lighting with working plane illuminance of 500 lx

- HIT 70 W / 942 (Projector-Mirror-system: metal halide lamps & ceiling mirrors)

- electronic ballast, not dimmable

- CCT= 4000K, R<sub>a</sub>= 90

- Total power consumption including ballast= 82 W

- LON/individual-controlled

<figure><img src="image_196.png" /><figcaption>**Figure 10-17.** Luminaires installation.</figcaption></figure>

<figure><img src="image_197.png" /><figcaption>**Figure 10-18.** Luminaire position.</figcaption></figure>
## Calculations

Room with area 20m²:

- 2 projector HID 70 W lamps and 1 CFL 55 W fluorescent lamp

- total installed power (2*82+62) W = 226 W

- lighting power density = 11.3 W/m²

Room with area 40m²:

- 3 projector HID 70 W lamps / 2 CFL 55 W fluorescent lamps

- Total installed power (3*82+2*62) W = 370 W

- lighting power density = 9.2 W/m²

Luminaire efficacy of lighting system:

- Projector-mirror-system 82 W, 6000 lm * 50% = 36.6 lm/W

- CFL Fluorescent system 62 W, 4800 lm * 60% = 50 lm/W

## Measurements

<figure><img src="image_198.png" /><figcaption>**Figure 10-19. Illuminance during a sunny day on working plane vs. outside horizontal illuminance.**</figcaption></figure>

Red curve: outside horizontal illuminance (on the roof)

violet curve: illuminances on the workplane next to the desk
## Illuminance distribution:

* $E_{\text{mean}}$: 552 lx

* $E_{\text{min}}$: 373 lx

* $E_{\text{max}}$: 725 lx

* $g1 = E_{\text{min}} / E_{\text{mean}}$: 0.68

* $g2 = E_{\text{min}} / E_{\text{max}}$: 0.51

* UGR: 17

<figure><img src="image_199.png" /><figcaption>**Figure 10-20. Illuminance distribution on working plane (only artificial light).**</figcaption></figure>

## Interviews:

* Questionnaires (60 subjects)

* Principal results:

- the automatic control of the daylight-lamella-system is deactivated in most cases, almost everyone prefers an individual (and constant) situation

- most employees are very satisfied with the light (and thermal) conditions of their working places

- artificial light (both CFL and HID) is switched on by the employees only when the illuminance gets lower than 100 lx.