Page 66 - Energize June 2022

TECHNICAL

Tuneable LED technology
There are several types of tunable LED
available.

Single chip Tuneable LEDs
In this version, a number of white LEDs of
different CCT are mounted in a single chip,
giving a cohesive source of light.

Tunable white strips
This is a very basic version which uses Figure 10: Tuneable LED striplighting (MSSled)
separate cool white and warm white LEDs
mounted close together in a strip format.
Individual controls are used for each field.
The two LEDS are typically cool white and
warm white.

Tunable white panels
These consist of a cluster of LEDs mounted
in a flat panel structure. There are wide
variety of flat panel and other light fitting
structures available on the market. Most Figure 9: Single chip tuneable LEDs (Lumitronix) Figure 11: Tuneable LED panel lighting (Helvar)
are paired with controllers designed for the
specific fixture.

Residential tuneable LED fittings
In addition to strip lighting and other
area lighting systems, individual tuneable
luminaires, which plug into a standard
light fitting, and where the control circuit
is integrated into the lamp structure, are
available. Control is by radio or Wi-Fi via
a hand or surface mount control, or by
a smartphone App. Controls allow both
dimming and colour change.

Energy efficiency and tuneable
lighting
Implementing tuneable lighting to improve
wellness and productivity may have an energy
trade-off. The Pacific Northwest National
Laboratory (PNNL) performed a study at a Figure 12: Plug in tuneable lights (GE)
Seattle hospital and found that approaching
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lighting with goals to improve circadian and References
other biological and behavioral functions 1. The well building standard: https://www.wellcertified.com/
leads to higher energy costs, because the 2. K Houser: “Human-Centric Lighting: Foundational Considerations and a Five-Step Design Process”,
lighting systems that do so often require https://www.frontiersin.org/articles/10.3389/fneur.2021.630553/full
higher illuminances. The bottom line is that 3. Nichia: “How to control the luminous intensity of LEDs”, Nichia application note SP-QR-C2-210734-1
if a lighting system goes from a high colour 4. S Keeping: “Defining the colour characteristics of white LEDs” https://www.digikey.com/en/articles/
temperature to a lower colour temperature, defining-the-color-characteristics-of-white-leds
the energy efficiency goes down somewhat. 5. US DoE: “Understanding LED color-tuneable products” https://www.energy.gov/eere/ssl/
Fortunately, today’s blue LEDs and phosphors understanding-led-color-tunable-products
have become so energy-efficient that most 6. J Feit: “Facts and fiction of tuneable lighting”, Buildings, 3 April 2018.
people don’t worry about the energy impacts
of colour tuneable lighting. 6 Send your comments to rogerl@nowmedia.co.za

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