OK, at Ivory Egg we could be viewed as a little KNX or DALI biased, so I promise to be as objective as possible and open to feedback here. At the end of the day we are independent, simply want to deliver the best solutions to our clients and I would hope this article, at the very least, will stimulate some form of debate. You can view the complete thread at AV Forums.

So, in terms of the players (at least who I perceive to be the market ‘leaders’ in this field), and again you may disagree with my selection, I have decided to look at the following solutions. This selection is based purely on the names I come across on a weekly basis:

• KNX
  KNX is a standardised (EN 50090,ISO/IEC 14543), OSI-based network communications protocol for intelligent buildings. KNX is the successor to, and convergence of, three previous standards: the European Home Systems Protocol (EHS), BatiBUS, and the European Installation Bus (EIB or Instabus).
• Crestron
  Crestron is the world’s leading manufacturer of advanced control and automation systems. They offer integrated solutions to control audio, video, computer, IP and environmental systems, and streamline technology to improve the quality of life for people in corporate boardrooms, conference rooms, classrooms, auditoriums, and in their homes.
• Lutron
  Lutron Electronics Company, Inc. is a privately held corporation that designs, manufactures, and sells lighting control systems and a variety of other related products. Its probably fair to say that Lutron lead the way in lighting control systems.
• Rako
  Rako provide state of the art digital dimming technology. Their innovative solutions meet the needs of a diverse range of applications by offering lighting systems that are simple to use, creative, easily installed and cost effective.
• DALI
  The Digital Addressable Lighting Interface (DALI) is a digital protocol for the controlling of lighting in buildings, such as electrical ballasts and dimmers.
• INSTEON
  INSTEON technology is a dual-band mesh topology employing AC-power lines and a radio-frequency (RF) protocol to communicate with and automate home electronic devices and appliances, which normally work independently. It is a home automation networking technology invented by SmartLabs, Inc., and was developed based on the X10 model for control and sensing applications in the home.

Not everybody active in this field, but a good starting point? Unfortunatley though, we have a bit of a problem when trying to compare these so-called competitors, as basically what we’re dealing with is a mix of different standards, manufactures and solutions that are all competing against each other. I would love to be in position to just compare like for like and publish the pros and cons of each, answer the questions in places such as AV Forum, but that would not provide a true representation of each solution (I hope I’m not stating the obvious here)…

For example, it makes sense on some projects to have a mix of KNX and DALI. As DALI is an open protocol for lighting control mainly in commercial buildings, while the growth area in KNX is for residential and LED. Take Heathrow Terminal 5, which has a KNX backbone with switches/PIRs etc and a gateway to DALI for the lighting. KNX can’t compete with DALI, as the DALI is fitted to the ballasts that control the lighting and sit in the actual light fitting. They are complimentary systems and we approach it from that point of view as we sell KNX/EIB DALI gateways at Ivory Egg.

In terms of KNX vs. some of the other systems, well Lutron is bar far the market leader in terms of pure lighting control. Rako on the other hand sell purely wireless lighting controls and they are great for DIY/retro-fit. As for INSTEON, which is again a wireless control technology, they currently have no European devices so it doesn’t really complete with KNX and is more of a competitor to the likes of Z-wave and EnOcean (which is another blog altogether). And finally  we have Crestron, who supply more AV & generic device control solutions.

It is worth pointing out that Crestron do provide a complete AV, lighting and control solution. It does it by controlling different devices from multiple manufactures and a wide range of different protocols via a central controller. From a consumer point of view Crestron is “Interface Centric” via tablet and in wall touch screens. This hides the complexity of using Lutron for lighting, X manufacturer for heating and Z for multi room audio. It is an expensive route to take, but on the positive side it is highly configurable.

KNX is standard based and developed from a consumer point of view. It is switch centric, in other words it is a compact and stylish intelligent switch on the wall that can easily control the ‘functions’ in a room (HVAC, lighting, blinds etc). KNX has 1,000s of products that are certified to work together, but this is not the case with Creston. That said most consumers wouldn’t know the difference, as most simply go on look and feel, and that is where market leaders such as Basalte and Gira score highly. Their products are innovative, look fantastic on the wall and at Ivory Egg we can supply a whole host of fittings for 13amp sockets that will coordinate with the wall switches. And to be fair, this is what the architects are demanding!

So difficult to draw conclusions really. I guess the big question I’ve not really answered is what are they main differences between Lutron and KNX? As Lutron is a central processor based with proprietary technology and KNX is a component/manufacturer open standard, does that mean the KNX open standard is the lowest common denominator (as claimed by Lutron) or does that mean you get vastly increased flexibility (as claimed by KNX)? Is Lutron only lighting control – on/off/dim or is it full integration. If KNX gives you full integration, then why would you even consider Lutron? All very valid questions…

Yes, KNX provides a holistic approach to efficient energy usage. It is not limited to lighting or heating or metering or appliances or AV or any other specific function for that matter. The KNX platform has been adopted by many highly respected major manufacturers with their vast choice of products covering all these product lines. In the longer term, this is also important to building owners, as any installation is future proofed for any changes/upgrades that could be needed. As KNX covers such a diversity of applications using one standard, it means cabling networks can be much more simplistic and single twisted pair cabling can often suffice, with multiple elements all operating together on a single network. As I’ve already mentioned briefly with DALI, a number of the KNX manufacturers have also developed ‘gateways’ to other control protocols. These simple devices are used to expand the capability of KNX control systems to provide the complete solution for a building.

KNX has also worked closely with management-level protocols such as BACnet to enable a close co-operation between these two standards when the project requires additional integration. Every KNX-compliant piece of equipment is fully tested and certified to this highly stringent standard by an independent regulatory body – It is only at this point that it can carry the KNX logo, as controlled by the international KNX Association of Brussels. Therefore there is total confidence in reliability and interoperability, whatever KNX devices are chosen. In the UK we have a growing network of integrators who have joined KNX UK to share their experiences and to help promote the standard. They can also assist consultants as well as building owners in achieving the optimum solution for their building and with KNX also accepted throughout the world (and with partnership agreements with more than 30.000 partners in more than 75 countries worldwide) from China to the United States as well as Australia and the Middle East, it truly is a worldwide standard.

Lutron on the other hand is recognised as the leading brand in terms of pure lighting control, and rightly so… It has many advantages and is easy to install, retrofitable and extremely reliable. Their systems are a proven, extensively implemented technology that offers 2-way communication, is scene capable and can dim any type of dimmable lighting. All this is backed by an industry leading company with a very long history and their systems are available in a large number of styles and finishes, all backed with a 7 year warrantee. Plus they too can integrate window/shade controls and offer relatively easy intregration with Crestron and other control systems. However, while I find it hard to criticize KNX (and again, I can hold my hands up and say yes we’re a little biased), to me there are some obvious disadvantages to Lutron. For one it only controls up to 32 lights (expandable to 64). Then there is the fact it has no dedicated processor, so it relies on an automation processor. In other words if this processor fails, then I’m afraid you have to manually override or you have no lights at all. However, the ‘biggie’  (in my experience anyway) is that expansion always seems more complicated than it needs to be and is certainly more expensive than with KNX products.

The choice of lighting control is a wide one one I’m afraid, the above is only our humble opinion.  To be honest, what you really need to do is decide what functionality you want and then see what systems can support your needs. Its important you select an installer that can advise you on the systems that you’re interested in. Price is always important, but do not make it the main point, and you need to always be thinking about upgrades/adding to the system in the future. Also think about who can you get to do changes and tweaks to the lighting control system (these things are never right first time and commercial clients and their staff especially can be very demanding)?Does the control system intergrate with other manurfacturers you may be using and don’t be afraid to ask for them to show you existing installations they’ve completed that are using the products you’re interested in. KNX is certainly the logical choice to me in terms of flexibility and meeting demand, especially if you need to integrate other systems such as heating, blinds, AV etc, but always keep an open mind and one eye on what each of these systems can deliver.

Home to around 15,000 students and at over 400 years old, a leading Scottish University has recently made some significant improvements to their campus lighting system. “For uniformity, every lecture room has a switch with four settings for a number of years now,” said Charlie Simpson, Senior Electrical Engineer for the University, “Bright, Medium, Dim and of course Off. And this has allowed our faculty members to change the lighting for their lectures and AV presentations.”

Customer Expectations

Charlie stated at the start that professors once used the dimming features for lectures when using the old overhead projectors. However, today they use computers with PowerPoint™ presentations and DVDs, but the need to vary the lighting in the classrooms still remains the same. “For years we built our own lighting control panels, and the cost was incredibly high per classroom, plus very time consuming for me and the team” said Charlie. “Then last year ago we switched to an ‘off the shelf’ DALI dimming configuration and got rid of the old 0- to 10-volt system/ballasts we were cobbling together. The DALI solution significantly reduced our costs and saved hours in terms of installation time.

For lecture rooms and other areas or lighting applications where complex scenes/reconfigurable zones were required, DALI dimming ballasts and controls now allow users to independently control multiple lighting zones. This technology is perfect for applications requiring sophisticated dimming such as lecture halls, conference rooms, lobbies, corridors and general faculty amenities such as libraries, IT suites etc.

Customer Comment

We were made aware of the Siemens GAMMA range of sensors, actuators, gateways etc and we did a trial by installing a simple configuration in one of our conference rooms and it worked exactly as needed. Then our lamp crew put the controller through its paces and, after extensive testing, we decided to roll out across the campus. We are now able buy an off-the-shelf system for lighting control for a very reasonable price. The fact the DALI dimming system is an open standard that can be purchased ‘off-the-shelf’ is incredibly important. The great thing about DALI is that its not a custom device and our staff can easily program it to assure uniformity throughout the campus. Custom building is so expensive and time-consuming, I just can’t believe we stuck with it for so long.

Top Features

1. Remote controls in all lecture rooms allowing control of main room functions such as lighting, HVAC etc.
2. N 525 E switching/dimming actuators that connect the KNX EIB with digital primary switching devices that have a DALI interface. There are 8 channels, of which each one has the capacity of a switching/dimming actuator. The DALI operating devices of each individual channel are directly wired so that no further additional commissioning procedure is necessary for the primary switching devices.
3. KNX / DALI N 141 gateways are DINrail mounted for the DALI ballasts and enable the receipt of switching and dimming commands, but also the send status information such as the failure of a lamp or the report of a detected error in the electronic ballast direct to Charlie.
4. Sun/antidazzle protection actuators for controlling all roller blinds.
5. Sensors for HVAC that detect the temperature and deliver the basic values for optimum control.
6. Motion/Presence Detection in all main hallways/corridors
7. Electrical Power Counter/Meter that allows Charlie to keep an eye on electrical power consumption at all times.

You can utilise lighting control strategies to significantly improve the performance of any building.  By simply designing room absence/presence detectors, daylight sensors and/or automated time-based controls with fluorescent dimming you can carefully control the lighting in an entire building and further reduce electricity usage.  This can result in not only saving energy, but also costs, especially in a large commercial building.  However, the dimming methodology required is always entirely dependent on the lamp or the ballast used.  The key dimming methods are detailed below and all of them can be easily achieved with KNX dimmers:

1. Mains dimming involves decreasing and increasing the voltage to the lamp and is the traditional form of dimming associated historically with a rotary dimmer.  A KNX universal dimmer performs this kind of dimming and is capable of sensing the type of load (trailing edge or leading edge).  It is now possible to mains dim some LED and CFL lamps, though it would always be recommended to use a proper dimming control method as below.

2. 0-10V is one of the earliest and simplest electronic lighting control systems; simply put, the control signal is a DC voltage that varies between zero and ten volts. The controlled lighting should scale its output so that at 10V, the controlled light should be at 100% of its potential output, and at 0V it should at 0% output (i.e. “Off”). Dimming devices may be designed to respond in various patterns to the intermediate voltages, giving output curves that are linear for: voltage output, actual light output, power output, or perceived light output. For dimmable Fluorescent lamps (where it operates instead at 1-10v, where 1v is minimum and 0v is off) the system is being replaced by DSI, which itself is in the process of being replaced by DALI. For more information see http://en.wikipedia.org/wiki/0-10v.

3. DSI – Digital Signal Interface is a protocol for lighting control in buildings (initially electrical ballasts). It was created in 1991 by Austrian company Tridonic ATCO and is based on Manchester-coded 8-bit protocol, data rate of 1200 baud, 1 start bit, 8 data bits (dimming value), 4 stop bits, and is the basis of the more sophisticated protocol Digital Addressable Lighting Interface (DALI). The technology uses a single byte to communicate the lighting level ( 0- 255 or 0×00-0xFF). DSI was the start of digital communication technology and was the precursor to DALI. For more information see http://en.wikipedia.org/wiki/Digital_Signal_Interface.

4. DALI – The Digital Addressable Lighting Interface is a digital protocol for lighting control in buildings, such as electrical ballasts and dimmers. DALI was established as a successor for the still market dominating 1-10v and an open standard rival to Digital Signal Interface (DSI), on which it is based. DALI is standardized in accordance with International Electrotechnical Commission IEC 60929, standard for fluorescent lamp ballasts. Each piece of operating equipment with a DALI interface can be communicated with over DALI individually. Using a bi-directional data exchange, a DALI controller can query and set the status of each light. As a standalone system, DALI can be operated with a maximum of 64 devices. Alternatively, DALI can be used as a subsystem via DALI gateways. For more information see http://en.wikipedia.org/wiki/Digital_Addressable_Lighting_Interface.

5. DMX – DMX512-A is an EIA-485 based communications protocol that is most commonly used for stage lighting control and effects. Developed by the Engineering Commission of USITT, the standard started in 1986, with subsequent revisions in 1990 leading to USITT DMX512/1990. In 1998 ESTA began a revision process to develop the standard as an ANSI standard, including a Public Review process. The revised standard, known officially as “Entertainment Technology – USITT DMX512–A – Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories”, was approved by ANSI in November 2004. This current standard is also known as “E1.11, USITT DMX512–A”, or just “DMX512-A”, and is maintained by ESTA. DMX512 was originally intended as a ‘lowest common denominator’ protocol for use between interfaces supporting proprietary protocols. However, it soon became the primary method for linking not only controllers and dimmers, but also more advanced fixtures and special effects devices such as fog machines and moving lights. DMX512 is unidirectional and does not include automatic error checking and correction, so it is not safe to use for applications involving life safety, such as controlling pyrotechnics or laser lighting display where audience or performer safety is involved. MIDI is sometimes used for this task. For more information see http://en.wikipedia.org/wiki/DMX_(lighting).

While there are many strands to carbon footprint reduction, commercial lighting is probably the most visible and emblematic of the struggle.

We all know that changing to low energy light bulbs can reduce energy consumption. But such lighting is still often left on when rooms are empty, dramatically illustrated by any night-time city skyline. Plus there is the residual heat generated which causes extra load on a facility’s air conditioning plant.

Constant Daylight
Simple timers can reduce some of this overhead, as can presence detection (which automatically switches lights on and off when someone enters/leaves a room) or absence detection (which requires manual light activation but automatically switch off when someone leaves.) But now there is a smarter and greener adjunct to these tools: Constant Daylight (also known as Daylight Harvesting.)

The idea behind Constant Daylight/Daylight Harvesting is simple: using a combination of presence/absence detectors, light level detection and intelligent software, a lighting controller adjusts the lighting of a room to complement current natural light, producing a comfortable, constant lighting load which is switched off when occupancy has ceased.

One product that includes Constant Daylight/Daylight Harvesting functions is the DLC1000 Light Control Module from Durable Technologies. This Light Control Module works in conjunction with multiple DLS1000 sensors to constantly monitor for absence and light levels, adjusting lighting for a comfortable working environment, eliminating it when no-one is in the room.

Using less power
So effective is Constant Daylight that in a recent installation, on a typically overcast British spring day, the DLC1000/DLS1000 combination kept the ambient light level in a classroom of 15 sq m at a steady 300 lux and used 60 per cent less power than conventional lighting. And in some cases, a bright, sunny day enables Constant Daylight to eliminate artificial light use altogether. Obviously Constant Daylight cannot be used at night, but presence/absence detection means that full lighting is only used when a room is occupied, changing your building to a low-carbon gap in the night skyline.

Durable Technologies designed the DLC1000 Light Control Module as a KNX device, it is certified to work with any of the thousands of other KNX building controls available from manufacturers world-wide, delivering the cost saving benefits of open standards at a time when budgets are tighter than ever.

That’s why Constant Daylight/Daylight Harvesting is a powerful and cost effective tool in your quest for ever greater carbon footprint reductions.

Top features

1. Heating and Cooling – the heating and cooling provided by Daikin is controlled through an interface from Intesis. THe possibilities for personal control and energy saving are realised by room and by area. Motion sensors allow for meeting rooms to be made comfortable when people are in them and then switched ‘off’ when they are vacated.
2. Lighting – luminaires with DALI balasts provide highly controllable light, cost effectively. Light dependency is dealt
3. Blinds – motorised venitian blinds can be independently controlled and the louvre angle adjusted to allow for variable external light conditions and to maximise, or minimise, the effects of solar gain depending on the season.
4. Energy monitoring – Using the Synetica datastream the energy use of the building is monitoried on a floor-by-floor and circuit-by-circuit level so the building service manager can see where the energy is being used, and can adjust it as he wants.

Full integration of all the essential building services (DALI lighting, heating, blinds, AV, Access control) in this busy and critical intensive care ward. Reliabilty not optional.

Project Description

Imperial College London Healthcare, QEQM Adult intensive care unit was moved into a new floor of an existing building. The challenge was to incorporate the all service requirements of such a sensitive space with the simple usability that is required for 24 hour use by a rotation of staff. KNX delivered a wide ranging solution from straightforward lighting control to more complex control of HVAC, TVs and access control.

• All functions are controlled from 21 x Gira InfoTerminalTouch 7″ touchscreens with KNX interface
• Lighting – DALI control of all luminaires by constant brightness and motion
• Blinds – venitian blinds lift and tilt to provide brightness control and privacy

Customer Comment

“We were suprised that there was such a comprehensive solution available. We had tried other systems in the past, but they were invariably not fit for such comprehensive applications On every occasion we asked more of KNX the answer was, “Yes”. The end result is an excellent solution for the hospital, and has been operating faultlessly since being commissioned.” Hospital M&E Services Manager.”

Top features

1. Wall mounted touch screens for nurse control of all room variables including the TV and a ‘crash’ situation
2. DALI lighting control throughout. Flexible levels and energy saving
3. HVAC control via BACnet from touchscreens
4. Control of wall mounted TVs from a Gira touch screen via IP
5. Access control to wards opening doors
6. Motion sensors on all corridors and rooms
7. Venitian blind control for brightness and privacy
8. Control of ‘Intelligent Glass’ for privacy between treatment rooms