Pitfalls of Intelligent Lighting
By Dr. Vincent Chow, CEO of En-trak
building had to do with the light system – specifically occupancy or motion
sensors. These automated systems turn on the lights when someone is occupying
the area, and they turn off the lights when nobody is there.
The main draw of automated lighting lies in its ability to help make energy use
more efficient in buildings. However, while automated lighting seems like an
easy plug and play solution, building owners should take a closer look at the
installation and consider any drawbacks carefully. As is often the case with
technology, what works in theory might have deal-breaking challenges in
practice. Let’s take a look at four downsides to sensor-based lighting control
in the office.
rules and best practices just to get standard results. A 90+ page guide on
sensor placement is not uncommon.
When all factors are considered, only a few areas like toilets, alley ways and
storage closets are suitable for motion sensor use. Moreover, it’s
difficult to be confident about your reliance on sensors if so many things can
be done incorrectly.
One of our customers installed motion sensors for their meeting rooms. Soon
after, they received consistent complaints from several women about the sensors
not working. It turned out that the sensors were placed too high and were not
detecting relatively shorter people entering the room. Fixing the problem was
time-consuming and costly.
Downside #2: Practical difficulties
There aren’t many things more frustrating than a motion sensor that doesn’t
work as expected. Whether it’s because of bad placement, low batteries, or some
form of interference, sensors do experience problems from time to time.
These problems can cause energy wastage or worse – staff frustration and
increased stress levels. In 2010, a guest sued a hotel when she fell and
injured herself in the toilet – the motion sensor had turned off the lights.
Sometimes it’s not even the fault of the sensors. We’ve seen significant
investments in motion sensors go down the drain because of traditional
occupants’ behaviours. For instance, a quick trip to the toilet before heading
home in the evening can result in half the office lights turning on for 10
minutes – not exactly energy saving.
Downside #3: Higher costs, longer payback
Adding sensors to your lighting control system increases the lifetime cost of
First, there’s the cost of the sensors themselves. Second, there’s the
expertise required to place them and calibrate them correctly, which takes time
and money. Third, there’s the ongoing cost of ensuring that your sensor-control
layout matches your changing office. Doing this often requires rewiring and
relocation of sensors.
If all of these deliver more savings than the extra costs, then it’s
worthwhile. The problem is that this is rarely the case. Sensors that control
lights in zones usually save LESS energy than individual fixture control without
The lack of precision counteracts the benefits of the sensors. And if you
install one sensor per fixture, your payback could get even worse. You end up
drastically increasing costs in exchange for only minor extra savings. Payback
in these cases takes as long as 4-7 years.
Downside #4: Lower productivity
To get the most out of your staff, you need to provide a focused environment, a
sense of control over their working areas, and a sense of ownership. And yet
sensor-based lighting control can detract from this feeling.
It distracts occupants with lights frequently turning on/off. More generally,
it subjects them to a frustrating automated system that does not always respond
to their needs.
We’ve seen cases where the entire control system has been removed due to
occupant dissatisfaction with sensor-based control. Unfortunately, the sensors
were the only way to control the lights, so when they were taken out, all of
the benefits of scheduling and optimization went with them.
Avoiding pitfalls and ensuring results
If you’re considering sensors for your office lighting controls, make sure you
understand what you’re getting into. Otherwise, you could end up writing off a
significant investment. Sensors have their place in some limited contexts, but
the question you must ask is: do you want sensors, or do you want results?
A good lighting system must be able to meet both your design and operational
needs. The powerful and inherent energy savings benefits of lighting control
can only be realised if your system is installed to the right standards.
Lighting which is easy to use, affordable and wireless. It provides a flexible
scheduling tool to handle public holidays, alternating weeks, and other
challenges which conventional zonal timers cannot achieve, giving you maximum
control over your lighting.
Imagine you need to re-configure your office layout to suit business needs.
En-trak Smart Lighting will allow you to alter your lighting configurations and
zoning with a few simple clicks, regardless of the existing wiring layout. It’s
as easy as that. In today’s context, getting the lighting system right is
crucial. This is because, beyond simple illumination, smart lightings are in
fact laying the foundation for the “Internet of Buildings”.
The potential of Smart Lightings and the Internet of Things (IoT)
on buildings will be explored at the upcoming Build Eco Expo (BEX) Asia.
For the lighting industry, the opportunities are immense. The sensors and
advanced controls already used in the industry can be put to even greater use
to realise a truly smart building in the future. A wrong investment will be
costly in such a rapidly evolving market.
 Hong Kong Green Building Council. (2013). Section 9.8 Case study for energy
saving, Hong Kong Green Shop Guide.