Retrofitting motion controls in commercial building lighting05 November 2020

Retrofitting workplace spaces with motion-controlled lighting conserves power and helps slash energy costs. But can you keep the existing lights or is it a matter of ‘rip and replace’? By Brian Wall

A motion-controlled lighting system can help save a great deal of money on energy costs by enabling manual or automatic management of the number of lights that are ‘on’ at any given moment. It also controls the intensity of those lights, to help create a productive and work-friendly environment. According to The Carbon Trust, going down this route and installing certain types of sensors could help you cut your lighting bills by as much as 30% (www.is.gd/alonox).

But what if you occupy a building where the existing lighting system is old and outdated? Are the costs involved in switching to a ‘smart’ system, for example, likely to prove prohibitive?

The good news is that, in most instances, the transition can be a relatively smooth and economic one. The prospect of having to rip out much of the existing fittings (and even wiring) is something that is likely to be a long way from reality. In fact, most modern lighting has been manufactured so it can be swapped out with legacy equipment.

At Signify (the name that Philips Lighting adopted in 2018, two years after its separation from former parent Philips), this is approach of the systems that it offers commercially and to consumers, both direct and through its distribution channel. “We have a wide range of lamps with the shape and form of what might now be referred to as ‘old technology’, but in LED [light-emitting diode] format,” says Peter Duine, the company’s sub-segment manager, office & industry professional systems. “This means that, typically, light tubes can be taken out and new LED technology fitted inside the existing metal fixtures – no need for these to be removed. There are also ‘smart’ or ‘connected’ versions, which brings into play smart technology, to automate how you control the lights throughout an office and indeed building, so they come on and go off automatically.”

SENSOR SENSE

Smart lamps are controlled by a sensor located in a room, without any adjustments needing to be made to the building itself. “So, there is no need to touch the existing wiring even. You just glue or stick the sensor to the wall or ceiling, with one sensor covering 6 to 10 people. Bigger spaces simply mean having multiple sensors. You can programme the lights to be ‘fully on’ – for example, in the area where people enter – and then modify that as they move through the room.” The depth of control also means that, when only one person remains, for instance, they can adjust the light level to suit their needs. “As the last person leaves,” he adds, “the light level drops from 2-3 Watts and then to zero.”

The simplest way for light levels to be set up after an installation is completed is via an app on the installer’s or retrofitting engineer’s phone – which the occupant can manually override via a wall switch. “All of this can also be done remotely and fine-tuned through an Internet connection, which is ultimately what makes the building ‘smart’.” Might not this result in conflict of interests between different users? “Not really. A local override will take precedence, which is essential in the case of an emergency, for example. However, when manual override times out, the automated control takes over again.”

Duine calculates energy savings where this degree of automation is in force can be quite profound – up to 70%. But that isn’t the end of the story. “LED and sensor technology has advanced so dramatically, that, if you were to take out all the old lighting and metal fixtures, and replaced these with new fixtures in every area, with a new sensor for each one, savings could be even greater – because you generate much more data and gain even greater control over the whole building. The facilities manager can see the heat maps and gauge how occupied a building is at any one time, so its efficiency can be monitored and optimised.”

FORWARD MOMENTUM

Paul Jones, country director for UK & Ireland at BEG Lighting Controls, says that the case for reinstalling lighting after abandoning what is already in place depends on the initial assessment. “However, efficiency of lights and the way that they can be controlled has really moved forward in the last few years. LEDs are more efficient, and often that can mean fewer fittings are needed to provide the same output.”

The best approach is to understand what the space is being used for, its dimensions and type of light fittings. “It is also essential to find out what is the energy usage and running costs. Is there natural light; would the user like scene control? BEG Lighting Controls offers an on-site assessment.

Is there an argument for staying with what you already have, but installing some form of local controls that also bring a reduction in energy consumption? Jones replies: “It really depends on the quality of lighting product already in place and what maintenance costs are associated. What are the drivers? If you are a business and a tenant for a few months or up to a year, the payback will be limited. But, if you are a landlord, facilities manager or buildings manager managing the corridors/stairwells/toilets, the payback will be calculated over a longer time period and, therefore, be greater.”

MAXIMISING THE PAYBACK

It is rare for a client to introduce a lighting control system independent of a lighting upgrade, states John Bailey, MD, The Benbow Group, which fits out and refurbishes the interiors of prestige commercial offices. “There are a number of reasons for this. The existing lighting system could have a number of compatibility issues and, if the luminaires are old, the control gear may not be compatible, which increases the possibility for failure. Also, to achieve the maximum benefit from a lighting control system, the existing luminaires would need to be dimmable. If they are dimmable, chances are that a lighting control system will already exist.”

He also references how the argument for upgrading a site to LED is based on energy saving, maintenance efficiency and quality of light. “The introduction of a lighting control system during the LED upgrade enhances these benefits.” Again, budget plays an important role in influencing the selection of the lighting control system: wireless, integrated controls within the luminaire or independent sensors – although the client requirements will also be a factor.

“A simple lighting control system would be the introduction of sensors within a space,” adds Bailey. “A basic example, and most often noticed, is an occupancy sensor within the entrance lobby of a toilet. An integrated luminaire lighting control, on the other hand, might be a warehouse where each luminaire has an occupancy sensor and possibly a daylight sensor – if the roof has skylights – resulting in each luminaire operating independently of one another. This means only the luminaires required to illuminate a task will function.”

Brian Wall

Related Companies
Benbow Interiors
Signify

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