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Logica Lighting Controls
Steve Jobs of APPLE said that one of his guiding principles in design was from Leonardo DaVinci when he said, “simplicity is the ultimate sophistication”. Jobs went to great lengths to eliminate anything that made his inventions more complex.
So if we start from this premise and apply it to lighting, the simplest
lighting control is the on/off switch on the wall that we all use to
turn on the lights in our homes and offices. It is how we have always
controlled lights. The light switch isn’t going to go away. It is
extremely efficient. When it is off, there is no energy used.
The wiring of a wall switch is very simple. We have a power source, a switch and a light fixture. So if we are going to add simple, sophisticated controls to lighting we have to start from here.
With only two elements, the switch and the fixture, what can we do to make the fixture controllable? We can put intelligence into the light fixture. The dominant fixture in US buildings is the 2’ x 4’ fluorescent fixture. The fixture comes in many forms but the troffer, the layin, the parabolic or the flat-lensed acrylic diffuser fixture are some of the names used to describe them.
They haven’t changed much since the 1940’s when they were introduced. They still have a metal housing, sockets, a ballast and lamps. They have not added any new parts. Now the introduction of a smart ballast with a microprocessor inside the ballast to control the lamps and the energy to the lamps is available.
By applying simple, sophisticated distributed intelligence technology
it is possible to have a light fixture that works like this: when you
turn on the switch for the first time, one lamp in the fixture comes
on. If that is enough light, you go about your business and you are
saving 75% of the energy on a four lamp fixture.
If you need more light, you turn off the existing wall switch and turn it back on within two seconds and then the second lamp goes on. You are actually sending a digital signal to the microprocessor in the ballast to turn on the next lamp. You can repeat the process until you have the light you need.
The big benefit of the smart ballast is that it can be communicated with from any computer network that speaks the same language. And it’s scalable. This is the game changer that moves the lighting fixture with a smart ballast onto the list of all the peripherals that the BAS system designers use to control the energy in a building. They can now control the lights as easily as they can control the other HVAC components they’ve been using for years.
Having the microprocessor in the ballast enables any computer on the same network to talk digitally to the light fixture. The ballast has a simple telephone port connection that can speak any language that you program into its memory.
The smart ballast light fixture has its own unique address in memory and therefore can be found and addressed over any network that speaks in the language in which it was programmed. Logica currently has three native languages in our ballast. One is an open protocol simple IEEE 485 language that we share openly. The other is the simple toggle commands that are sent over the power wire (but are not power line carrier signals). And the third is the MODBUS language. On the Tridium platform it is possible for any building automation system with a LonWorks, BacNET or ModBUS operating port to speak to our ballasts.
Dimming ballasts have been around for over 50 years and they have gotten much better at providing a changing luminance from fluorescent fixtures. The energy savings of a dimming ballast is not linear with the amount of light produced. There is a place for the dimming ballast and the control it offers.
A dimming ballast needs to have a controller to make it operate. The addition of a controller to the fixture or string of fixtures greatly simplifies the use of the dimming ballast. The controller provides a four-scene preset of lighting levels that are predictable, repeatable and are able to be activated by a wired control panel, a wireless controller or a digital computer signal.
The control of lighting and the use of lighting is about more than just saving energy, however. Energy management and building automation systems really focus on exactly how many watts per square foot are being used in each area of the building. But the quality of the lighting is another major concern of the building occupants, company management and the architects and designers of the space. And to have an automated building meet the needs of its users this quality must be taken into account – but often isn’t.
Lighting controls have only three things that effect light. We can control the intensity, color and movement of light. It is the same with theatrical lighting. In our controls we must be aware of these three elements of lighting and their impact on lighting quality.
My background is theater and I was captivated when I saw my first play in a real theater. The way the main character was lit and the darkness around me that made me forget all the others in the theater and put me in a personal relationship with the actor was magic. It was then that I knew that lighting was very interesting – and powerful. I went on to act in college but was drawn to the back stage lighting controls and learned the art of lighting to create effects, control attention of the audience and to cast the best light on a scene.
Even though we are not doing theatrical lighting in office buildings and commercial buildings we still have to set the mood for the tasks to be done and provide enough of the right kind of light to accomplish the tasks. We need to know the focus for each area and the quantity of light that will enable the occupant to be the most productive and comfortable without wasting energy.
The colors and conditions of the rooms where we are controlling lights will affect the amount of light required. The age and eyesight of the occupants of the space will also make a difference in the amount of light required.
Michael Siminovitch, director of the California Lighting Technology Center at the University of California, Davis said “We learned that people buy service, not energy savings.” Other studies have shown that financial savings are not the main reason that people buy lighting controls. It is what the controls produce in terms of customer satisfaction that counts.
All of this points out that lighting is subjective. It is based on personal preferences and there is not any one absolutely correct answer for the exact lighting effect required in any space for different users and tasks. That means that user controls are really quite necessary for the maximum productivity and comfort of the occupant of an area.
The obvious answer is to have a control at each desk or in each work
area where a user of the space could adjust the light to the level they
wanted. This is now practical and affordable. There are many ways to
give local control to the user of a space now. If they have a computer
on their desk we can have a program on their computer network that
allows them to control their own lighting in their area.
Wireless RF controls are now cheaper than wired solutions on an installed basis. Switches can be added anywhere by using kinetic switches that send RF signals to local fixtures.
Smart phones can have an APP that can be used to activate and adjust the light levels in their area if the network is on a system where the IP address is available on the internet. This seems to be the way of the future since use of smart cell phones is becoming so common.
We can have automatic lighting controls based on occupancy sensors that turn lights on to a preset level when someone comes into a room and goes back to another preset level when the person leaves the area.
Photo sensor controls for Day Light Harvesting are also available to maintain lighting levels at a uniform level.
It is our position that lights should be turned on by an occupant when they enter the space and not by a time clock unless it is a clearly automatic start time for a large number of occupants like a school or factory setting.
The design of a lighting control system for a specific building is a difficult job. The industry has relied on various manufactures to supply the electrical engineers or lighting designers with a sample layout based on the products they have to sell rather than selecting a method of control to be followed. The shortest distance between two points is a straight line. However to make their controls work, many companies introduce extraneous parts into the design because they don’t have the ability to talk directly to the fixtures. Now that the technology exists to talk directly to fixtures, designers should not be hesitant to specify the least expensive and direct control strategy to get the controls they want. Simple sophistication.
The growing dominance of LED lighting fixtures will make a big change in lighting control. Now we will be able to have a light source that produces more than 100 lumens per watt, (the maximum that fluorescent lamps can achieve currently) and we will have 0-10 Volt remote dimming control that is linear.
LED’s can be dimmable so that intensity control is possible. Some LED’s have the ability to remotely change colors so we will be able to have fixtures that can be any color temperature we choose or they can be any one of thousands of other colors. All of this will be able to be accomplished by remote digital signals. The embedding of a microprocessor in the preset controls for the 0-10V LED drivers will allow the ultimate in lighting controls.
The cost of LED fixtures is dropping so there is a clear trend that the use of them will eventually be the lighting source of choice. However, because the cost of LED’s there is still a long life for the millions and millions of fluorescent fixtures now in use throughout the world.
Minvalo, a controls distribution company in Minneapolis, MN, has an installation of 65 fixtures in their City Desk area where they are controlling six zones of lights from a building automation controller using Modbus commands. To our knowledge this is the first installation where a BAS system is talking directly to light fixtures. We know it works and it is feasible to use this technology to enhance the lighting control in buildings as well as to control the energy usage.
In summary, to make sure that you get a lighting control system that the building owner or occupant will use; make it simple. Avoid systems with panels, relays and control boxes. Insist on a system where the controls talk directly to the light fixtures. The protocol should be open so that anyone can bid on and supply the equipment. Once you establish that the fixtures and controls should be on a Local Area Network with distributed intelligence you will have the most direct and least expensive installed system available. Make sure that it can connect to your existing or planned building automation system.
Lighting is every
bit as important as any other part of a commercial
building. It deserves to have the simple sophistication that we are
used to in the computer systems that are common in fire alarm systems,
HVAC controls, Security systems and card access systems. Once it’s
digital anything is possible.
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