Hotel lighting should no longer be judged by aesthetics alone. Human-centric healthy lighting is now directly shaping your pricing power and guest reviews.

Turn “sleeping well, using things effortlessly, and moving safely” into value that guests can immediately feel.

---

What you think is a “service issue” is often actually lighting destroying the experience.

Guests rarely write words like “glare,” “flicker,” 或 “color quality” in reviews.

What they usually say is:

• “The lights are harsh. My eyes get tired.”
• “I couldn’t sleep well at night. I woke up many times.”
• “The lighting at the mirror looks strange—my face looks awful.”
• “I almost fell when I got up at night.”
• “The switches are too complicated. I couldn’t figure them out.”

Behind all of these complaints is the same invisible variable: the lighting experience.

And that lighting experience is directly affecting the three things you care about most: reputation, room rates, and repeat stays.

Why will it be harder next year if you don’t act now?

1) Reputation risk

When negative reviews accumulate, the cost is not replacing lights—but buying back trust with discounts.

When guests feel “uncomfortable” or “not worth the price,” ratings gradually decline.
You may think the service team is to blame, but in reality, lighting is lowering the baseline experience score.

2) Pricing risk:

Your competitors are selling “sleep and experience,” while you are still selling “renovation.”

Hotels at the same tier increasingly emphasize: good sleep, relaxation, atmosphere, and ease of use.

No matter how new your finishes are, if the lighting makes people tired, your premium pricing power will be compressed.

3) Operations risk:

The later you act, the more fragmented—and harder to maintain—it becomes.

Multiple renovation phases, room types, suppliers, and control systems…
Delaying a year often does not save money; it turns a one-time project into long-term operational bleeding.

What does “human-centric healthy lighting” actually do in hotels?

In one sentence:

Help guests stay alert during the day and want to sleep at night;
use spaces intuitively, walk safely;
see comfortably and feel relaxed.

It is not medical light therapy, and it is not “the brighter, the more premium.”

It is about using People × Space × Activity × Time to turn lighting into a deliverable experience system.

The three most failure-prone scenarios

(and the biggest sources of negative reviews)

If you want minimum investment with the fastest impact, start here:

1) Bedside & nighttime movement

No startling, no glare, no disturbing your partner

• Bedside reading lights should illuminate the book, not the face
• Night movement should rely on low-level guidance lighting (under-bed, skirting, bathroom entry)—dim but continuous
• Sensor lights must be “polite”: no sudden bursts of brightness

2) Bathroom mirror lighting

Don’t make guests look older, dirtier, or more tired

• Mirror lighting should reduce shadows, render skin tones naturally, and avoid point glare
• Bright ≠ comfortable
  The key is glare control + light distribution

3) Corridors & circulation

Sense of direction + sense of safety

• Too dark: oppressive, unsafe, complaints
• Too bright: harsh, cheap-looking, disruptive at night
• A better approach: rhythmic brightness, low-level guidance, and night modes

A “good-to-sleep, easy-to-use, easy-to-sell” guestroom requires four layers of light

To upgrade a room from a “bright box” to an “experience room,” the most effective structure is four-layer lighting:

1. Ambient lighting: overall brightness (dimmable)
2. Task lighting: desk, bedside reading, wardrobe, luggage bench
3. Accent lighting: walls, headboard background, curtain coves, artwork
4. Night lighting: low-level guidance (safe, non-disruptive)

Luxury is not about being darker—it is about clearer hierarchy and more intelligent light.

---

Four technical bottom lines

No mysticism—only outcomes

Even without complex metrics, hotels must at least ensure:

• Glare control: no visible hotspots, no eye fatigue
• Flicker control: especially in dimming, night lights, and long-duration corridor lighting
• Spectral strategy: support alertness by day, avoid over-stimulation at night (especially near beds)
• Color rendering & skin tone quality: critical for guestrooms, bathrooms, and restaurants

These four bottom lines determine whether guests stay longer, sleep better, and leave positive reviews.

---

The decisive factor: controls and “one-touch scenes”

Many hotels choose good luminaires, but fail at one sentence: “Guests don’t know how to use them.”

At minimum, adopt a three-button logic that guests understand in 3 seconds:

• One-touch All On
• One-touch Relax
• One-touch Night

Additionally:

• Bedside controls should handle the most common actions
• Night mode must be gradual, indirect, and non-startling
• Backend parameters should be replicable, traceable, and maintainable long-term

If controls fail, even the most advanced healthy lighting becomes meaningless.

---

The safest path for owners:

Start with a mock-up room and let data speak in 30 days

Owners fear two things most: spending money with no results, and construction affecting revenue.

The recommended approach is not a full-scale overhaul, but a low-risk pilot:

✅ 30-Day Mock-Up Room Plan (Recommended)

• Select one floor or one room type as a pilot
• Focus on: sleep comfort, nighttime safety, mirror experience, ease of operation
• Minimize ceiling work; prioritize luminaires, controls, and scenes
• Acceptance criteria go beyond illuminance: include glare, flicker, color quality, and scene performance
• After launch, track data: review keywords, complaint rates, return visits, and pricing elasticity

With a mock-up room, decisions are data-driven. Without one, debates rely only on feelings.

---

Conclusion:

Lighting is not a cost center—it is a visible lever for room rates and reputation

You may not call it “healthy lighting,” but you cannot ignore what it delivers:

Guests sleep better, feel it’s worth the price, and want to come back.

Your competitors are already differentiating through experience. The later you act, the more likely you’ll have to chase them with discounts.

---

Action Recommendations

If you are an owner or general manager:
→ Start with a mock-up room and the three highest-risk scenarios. Let results lead.

If you are a designer or consultant:
→ Use four-layer lighting + one-touch scenes + four technical bottom lines
as a deliverable and acceptance checklist.

Color temperature is not circadian rhythm: Clarifying ‘spectrum → metrics → implementation’ all at once

In recent years, “circadian lighting” has become increasingly popular in the industry, but a common misconception has also emerged:

• Treating color temperature (CCT) as a direct proxy for circadian strength (as if the colder the light, the stronger the circadian effect, and the warmer the light, the weaker it is).
• Equating full-spectrum light directly with “healthier” or “more circadian.”

Here’s the conclusion upfront:

Circadian effects are not determined by color temperature alone. They are governed by the combination of:

Spectral Power Distribution (SPD) received by the eyes × Vertical illuminance at eye level (Ev) × Time (period, duration, and prior exposure).

Below, we will clarify the relationship between CCT → spectrum → CS → CAF → m-EDI → EML using a framework that moves from physical quantities, to metrics, to standards and implementation.

---

1) Separate Three Things: Appearance, Spectrum, and Light reaching the eyes

A. Color Temperature (CCT): An appearance parameter indicating “warmer” or “cooler” light, derived from chromaticity coordinates.

B. Spectrum (SPD): 的 physical distribution of energy at each wavelength.

C. Light received by the eyes: For the same lamp, vertical illuminance and spectrum at the eye level vary depending on space, angle, reflection, and distance.

Key point:

The same CCT can correspond to many completely different SPDs (common in the industry due to different LED peak wavelengths, phosphors, optical designs, or mixing algorithms).

Therefore:

• 4000K ≠ fixed circadian stimulus
• 6500K ≠ automatically stronger
• Full-spectrum ≠ automatically more effective

---

2) What does circadian lighting focus on? Start with the “melanopsin pathway”

Human circadian rhythms and non-visual effects such as alertness are primarily linked to the ipRGC/melanopsin pathway. Therefore, modern metrics are mostly described based on melanopsin-weighted responses.

的 CIE S 026 system integrates the five photoreceptor types (including melanopsin) into a single measurable framework.

---

3) m-EDI: Converting “spectrum × illuminance” into a comparable circadian dose metric

What is m-EDI?

m-EDI (melanopic Equivalent Daylight Illuminance) can be intuitively understood as:
The stimulation of melanopsin by the current light is equivalent to the stimulation produced by D65 daylight at a certain illuminance.

How is m-EDI calculated, and how does it relate to spectrum and illuminance?

CIE S 026 introduces a useful bridging quantity—melanopic DER (commonly called the M/P ratio):

melanopic DER = m-EDI ÷ photopic Ev

(This is the melanopic efficacy relative to photopic illuminance.)

From this, it follows directly:

m-EDI = Ev × melanopic DER

(This is an algebraic identity based on the definition, not an empirical formula.)

Why this matters: It directly dispels two common misconceptions:

1. Discussing CCT alone without considering Ev (vertical illuminance at the eye) = meaningless discussion of circadian effect.
2. Discussing “full spectrum” without considering DER and Ev = still meaningless for circadian impact.

---

4) EML: Commonly cited in the WELL framework and Its Conversion to m-EDI

What is EML?

EML (Equivalent Melanopic Lux) frequently appears in WELL-related contexts. Academia has clarified that EML is not a standard quantity in CIE S 026, but it can be linearly converted to melanopic EDI:

melanopic EDI ≈ 0.9058 × EML

Implication:

When you see an “EML threshold” in a project, don’t worry—it can essentially be converted into the m-EDI framework, which is sufficient for practical engineering communication.

---

5) How to use WELL v2? Applying “metrics” to “duration × location”

WELL v2 (in the Light concept, L03 / Circadian Lighting Design) emphasizes not the lamp parameters, but the actual circadian light exposure received by people.

For example, at a workstation, the standard requires that within a specified time window, a certain duration of EML or m-EDI thresholds must be met (commonly interpreted as “at least 4 hours, starting accumulation no later than noon,” etc.).

The key insight: WELL drives real industry progress by shifting the focus of “circadian lighting” from marketing claims about fixtures to the actual exposure dose in a space, considering location, direction, time of day, and duration.

---

6) CS and CAF: Why they cannot be simplified as “just another color temperature”

What is CS (Circadian Stimulus)?

CS comes from the LRC model (Rea / Figueiro et al.) and is used to describe the strength of light’s stimulation on the human circadian system, with modeled correspondence to melatonin suppression. It is non-linear and has thresholds and saturation regions.

This means:

• CS is not synonymous with m-EDI and cannot be used interchangeably in a linear manner.
• The same m-EDI value can produce different CS responses depending on spectral composition, field of view, and adaptation state.
• In engineering, do not forcibly convert it into a single number to compare all scenarios.

What is CAF (Circadian Action Factor)?

CAF is commonly used in DIN/European contexts. Essentially, it weights the spectrum by a circadian action spectrum and compares it to photopic illuminance (similar to another form of M/P ratio) to express relative circadian effectiveness.

• CAF is also not color temperature.
• It depends on SPD but uses a different action spectrum than m-EDI or CS, so comparisons across metrics must be done carefully.

7) A “Relationship Diagram” to Completely Separate the Misconceptions

You can use the following “mental model” to educate your team and clients:

(Appearance Layer)

• CCT, Duv: Describe “what white looks like”
• Important: This cannot directly determine circadian strength

(Physical Layer)

• SPD (Spectral Power Distribution) + Ev (Vertical Illuminance at the Eye) + Time (time of day / duration / historical exposure)

(Metric Layer)

• m-EDI (CIE S026 system): Ev × melanopic DER
• EML (commonly used in WELL): approximately linearly convertible to m-EDI
• CS (LRC system): non-linear, modeled in relation to melatonin suppression
• CAF (DIN/European system): another weighted spectral ratio expressing relative circadian effectiveness

(Standards / Implementation Layer)

• WELL v2: integrates threshold + duration + measurement location into rules
• CIE S 026: provides a unified, measurable language (α-opic, especially melanopic)

This framework separates appearance, physical measurement, metrics, and standards—making it clear that color temperature alone does not dictate circadian effect.

---

8) Practical Checklist for Designers: Don’t Be Misled by CCT

When designing a circadian lighting plan—or reviewing someone else’s—make sure to clarify these five key points:

1. Measurement plane: Are you measuring at the eye-level vertical plane or the work surface horizontal plane? (Circadian effect depends on light entering the eyes.)
2. Data provided: Do you have the SPD/DER, or just the CCT? (CCT alone is insufficient for serious circadian evaluation.)
3. Daytime target dose: What is the m-EDI/EML goal, and for how long should it be maintained? (Dose = intensity × duration.)
4. Evening/nighttime strategy: Is there an upper limit strategy to avoid phase delays or melatonin suppression? (For example, research recommends significantly lowering melanopic EDI at night.)
5. Integrated design considerations: Have you accounted for spatial reflection, beam distribution, viewing direction, and control strategy together? (Luminaire parameters are always just the starting point.)

This checklist ensures circadian lighting is engineered for actual human exposure, rather than relying on superficial metrics like CCT alone.

9) Conclusion: The Scientific Bottom Line for Circadian Lighting

If the industry continues to treat “CCT = circadian effect” 和 “full-spectrum = circadian effect” as common knowledge, two consequences will inevitably occur:

1. Professionals who rigorously implement space-based exposure dosing will be driven out by less rigorous practices.
2. The market will lose trust in circadian lighting, because delivery cannot be verified.

The good news is: CIE S 026 provides a common measurement language, and WELL v2 embeds verifiability into the standards. What the industry truly needs is to use these languages correctly and completely, ensuring circadian lighting is both measurable and actionable.

---

References & Further Reading (recommended):

• CIE S 026 / melanopic EDI definition and measurement (Manchester Lucas group)
• Melanopic DER (M/P ratio) and CIE S026 terminology
• EML ↔ melanopic EDI conversion discussion
• CS (Circadian Stimulus) and its threshold/saturation explanation (IES/LRC)
• CAF (DIN system) definition and usage in research/engineering
• Daytime/evening/nighttime melanopic EDI exposure recommendations (Brown et al., PLOS Biology, 2022)
• WELL v2 L03 (Circadian Lighting Design)

0) Defining the Three Types of Light

1. Full-Spectrum White
   • Continuous energy distribution in the visible range, fewer “gaps.”
   • May improve material and color realism, but comfort and health depend on system factors like glare, illuminance, timing, and flicker.
2. Wide CCT White (1800–12000K along the Blackbody Line)
   • Not about wider gamut or saturation; it provides a wider range of white-light semantics along the Planckian locus.
   • Allows more continuous control compared to standard white points (2700–6500K), supporting nuanced spatial ambiance.
3. Full-Gamut Color
   • Chromaticity can deviate from the blackbody line, covering a larger gamut (multi-channel/multi-primary).
   • Strong for emotional and immersive experiences but requires reproducible coordinate systems for scalable use.

---

1) Vision Dimension: Seeing Clearly, True, and Comfortably

• Full-Spectrum White: Often perceived as more natural, but evaluation should go beyond CRI Ra. Modern TM-30 metrics (Rf for fidelity, Rg for gamut) better separate color realism from vibrancy.
• Wide CCT White: Supports nuanced white-light atmosphere without introducing color semantics. Accuracy requires consistent color-point verification over time.
• Full-Gamut Color: Powerful for narrative and immersion but most susceptible to irreproducibility if coordinates aren’t standardized.

---

2) Circadian Rhythm Dimension

• Not “the closer to sunlight, the better.” The key is dose and timing, measurable via CIE S 026 α-opic metrics (e.g., melanopic EDI).
• Full-Spectrum White: May support both vision and rhythm but could overstimulate at night if vertical illuminance is high.
• Wide CCT White: Good tool for dose-engineering circadian effects; works only with closed-loop α-opic vertical-plane measurements.
• Full-Gamut Color: Allows precise spectral design but relies heavily on measurement consistency.

---

3) Emotional Dimension

• Highly culture- and context-dependent.
• Wide CCT White: Supports multiple emotional contexts (relaxation, focus, alertness).
• Full-Gamut Color: Amplifies narrative and atmosphere but must have reproducible chromaticity–luminance–spectrum; otherwise limited to demonstration projects.

---

4) Standard Gaps

• Many industry chains still rely on legacy reference spectra assumptions (“Standard A light source era”), leading to mismatches in LED, multi-channel, and tunable systems.
• CIE 251:2023 recommends LED reference spectrum L41 to supplement Standard A for calibration, crucial for SDL algorithms.

---

5) White-Light Consistency: Duv, SDCM, and Continuous Tolerance

• Standards should evolve from single-point tolerance to system-wide tolerance across 1800–12000K, with anchor-point or full-range verification.
• Full-gamut color requires independent reproducibility metrics; Duv alone cannot describe its consistency.

6) Three Practical Industry Recommendations

1. Upgrade report checklists for SDL era
   • Include SPD, full-range CCT (1800–12000K), Duv/Δu′v′, color performance (TM-30 Rf/Rg), circadian metrics (α-opic EDI/DER).
2. Move from lamp standards to system standards
   • Human-centric lighting is system-level: device + space + time + human.
3. Turn Software-Defined Light from marketing into engineering
   • Measurement reference: LED reference spectrum (L41)
   • Chromaticity reference: Δu′v′ / u′v′ circles
   • Human-centric reference: α-opic metrics and computation tools

---

Conclusion

The true opportunity is not the hype around “full-spectrum,” but filling the gaps in reference frameworks:

• Unified measurement standards
• Consistent chromaticity tolerance language
• Shared human-centric metrics

Otherwise, SDL risks becoming fragmented—algorithms diverge, systems are hard to verify, and trust cannot be built at scale.

Why Human-Centric Lighting Must Enter the Era of System-Level Evaluation

In the lighting industry, “flicker-free” has almost become a taken-for-granted label.

Many luminaires state clearly in their specifications:

• PstLM ≤ 1.0
• SVM ≤ 0.4

Everything appears compliant, reassuring, and professional. Yet in reality, we repeatedly hear feedback from offices, schools, healthcare facilities, and high-end residential projects:

“All the data meets the requirements, but people still feel uncomfortable.”

So where does the problem actually lie?

I. Flicker Is Not a “Product Attribute”

First, one point must be made clear: Flicker is not an attribute of a single luminaire—it is a system behavior.

Laboratory testing of a luminaire usually assumes:

• A single luminaire
• A single driver
• Static dimming
• Short-duration measurement
• Focus on horizontal illuminance

Real spaces, however, are completely different:

• Multiple luminaires operating simultaneously
• Multiple drivers, often from different batches
• Dynamic scenes and transitions
• Long-term exposure
• Vertical eye-level perception

It is precisely at this moment that many “flicker-free” promises begin to fail.

---

II. Why “Compliant Data” Cannot Guarantee Real Comfort

Across years of on-site evaluations, we have repeatedly observed several typical issues:

• Single-luminaire tests pass, but instability appears once multiple luminaires are combined
• Static dimming is fine, but discomfort arises during scene transitions
• PWM and CCR mixed together, increasing waveform complexity
• Driver aging causes flicker risk to increase year by year

This is not the problem of any single manufacturer. It is the result of an evaluation logic that remains stuck at the device level.

Metrics such as PstLM and SVM are critical—but they all depend on assumptions:

• Under what conditions are they measured?
• For how long?
• In which operating state?

When these assumptions change, fluctuations in values do not indicate “instrument error.” More often, they indicate that system complexity has been revealed.

III. From Luminaire to Space: The “System Amplifiers” We Overlook

From a system perspective, flicker is amplified by at least four factors:

1️⃣ Multi-luminaire interaction
Phase differences and noise coupling between drivers are often invisible in single-luminaire tests.

2️⃣ Dynamic scenes and control systems
Changes in brightness, CCT, and time-based programs are central to HCL—and also the most easily overlooked flicker sources.

3️⃣ Complex waveforms
Multi-channel mixing, auxiliary LEDs, and sharp peak waveforms can render traditional metrics like “percent flicker” ineffective.

4️⃣ Time and aging
Electrolytic capacitor degradation, firmware updates, and changes in electrical environments can make a system years later fundamentally different from its initial commissioning.

簡而言之： Flicker is not a “measure once and forget” issue—it is a system phenomenon that emerges over time.

---

IV. What Is the Real Challenge of Human-Centric Lighting (HCL)?

Today, HCL is no longer just about spectrum, illuminance, or circadian rhythm.

If time and system behavior are ignored:

• Even the best circadian design can be negated by flicker
• Even the most advanced control systems can create discomfort
• Even perfect parameters may fail to translate into real experience

This is why we consistently emphasize the shift: From “flicker-free” to “flicker-controlled.”

---

V. System-Level Flicker Evaluation Is Not About Chasing a “Perfect Number”

At Lighting Recipe Studio, we do not treat any instrument as an “absolute judge.” What we focus on instead is:

• Multiple points (spatial)
• Multiple states (scenes)
• Multiple timeframes (lifecycle)

Through comparison, trend analysis, and worst-case scenario evaluation, we ensure that design intent remains aligned with real experience over time.

The role of in.Licht is precisely that of an on-site reference and system diagnostic tool—not a shortcut that replaces design thinking.

---

VI. A Verifiable Reference Case

In the StrongLED Headquarters project in Suzhou, we participated in and fully documented a rare but important achievement:

The world’s first project to achieve full marks for Light Concept under WELL Building Standard v2 at the Platinum level.

Its success did not come from a single “miracle luminaire,” but from:

• System-level flicker control
• On-site validation of dynamic scenes
• Continuous calibration during long-term operation

This proves one thing: System-level human-centric lighting is difficult—but not impossible.

---

VII. Conclusion: What Does the Industry Truly Need to Upgrade?

If flicker continues to be treated merely as a “compliance label,” human-centric lighting will remain nothing more than a slogan. But if we are willing to acknowledge system complexity, time effects, and the gap between data and lived experience, then:

Human-centric lighting can evolve from a concept into reliable, long-term value.

This is a challenge that designers, engineers, manufacturers, and standards organizations must face together. And it is no longer a question of the future—it is already happening now.

When “health” remains just a slogan, it is often only a wish.
When “health” is quantified, continuously monitored, and delivered in a visible, actionable way, it becomes a truly operational lifestyle.

We are excited to share that in the results of the 8th “Smart Lighting Cup” Outstanding Member Awards, organized by the Shanghai Pudong Intelligent Lighting Association, 燈光配方工作室 was selected for the Health Lighting Special Award.

This honor belongs to every professional who believes that “good lighting deserves to be redefined”, and it reflects the direction we have consistently pursued — moving from lamp specifications to measurable health outcomes.

01｜Behind the Award: The Industry Is Turning “Health” from Concept into Practice

的 “Smart Lighting Cup” evaluation is based on company submissions, expert reviews, and verification of actual participation throughout the year, emphasizing openness, fairness, and transparency.

This reflects a shift in how the industry evaluates lighting. The focus is no longer just on brightness, aesthetics, or smart functionality. Today, the key questions are:

• Does light truly support human circadian rhythms, mood, and focus?
• Can health outcomes be measured, tracked, and delivered?
• Can lighting, together with thermal comfort and air quality, form a complete, integrated healthy environment system?

This evolution in the industry is precisely the reason In.Licht Well was created — to provide actionable, measurable solutions for healthy indoor environments.

02｜What Is In.Licht WELL: An “Operational” Healthy Light Environment System

In.Licht Well does not treat healthy lighting as simply “a certain color temperature or brightness.” Instead, it approaches it as a sustainable, operational environmental system that integrates three key elements:

• Light (Visual & Circadian Support): From visual comfort to rhythm-supporting illumination
• Thermal Comfort: Making spaces not just “look comfortable,” but also feel livable
• Indoor Air Quality (IAQ): Ensuring that the safety and quality of the air we breathe can also be monitored and managed

In short, In.Licht Well makes health perceivable, visible, and interactive.

03｜Why It Aligns with WELL: From “Code Compliance” to “Verifiable Outcomes”

In WELL projects, the challenge often isn’t design concept, but rather:

• Does the system consistently perform after installation?
• How is the data recorded and verified?
• Do users actually perceive the difference?

The advantage of In.Licht Well is its closed-loop delivery approach:

A. Light – From “Lighting Effect” to “Circadian Support + Visual Comfort”

• Daytime: Supports alertness and focus—not by simply increasing brightness, but by delivering the right quality of light
• Nighttime: Minimizes overstimulation, maintaining the boundary of “dark when it should be dark”
• Simultaneously addresses glare control, comfort, emotional ambience, and scene experiences

B. Thermal Comfort – Making Spaces Truly Livable

• Discomfort from heat or cold can directly impact focus, sleep, and emotional stability
• In.Licht Well integrates thermal comfort into the same health-operating logic, ensuring comfort is achieved through data and strategy, not luck

C. Indoor Air Quality – Turning “Invisible Risks” into “Understandable Metrics”

• When air quality is visualized and linked with alerts, health shifts from a subjective feeling to a manageable, measurable metric

In short, In.Licht Well upgrades WELL alignment from simply meeting documentation requirements to delivering tangible, verifiable health outcomes.

04｜Why It Also Aligns with “Quality Homes”: Turning Health from “Specifications” into “Living Experience”

The key to a truly great home isn’t in materials or features, but in the long-term living experience:

• Are residents alert and focused during the day?
• Do they sleep soundly at night?
• Are they comfortable and relaxed in summer and winter?
• Does the indoor air inspire confidence?

In.Licht Well delivers value by transforming a “good home” from a one-time handover into a long-term, operable health asset:

• For residents: Health becomes visible, understandable, and participatory
• For developers/property managers: Health comes with data, proof, and opportunities for continuous improvement
• For designers: Design evolves from an aesthetic work into a verifiable, health-focused outcome

In essence, In.Licht Well makes health actionable and sustainable, bridging the gap between building specifications and real-life living experience.

05｜Our Message: Gratitude to the Industry and an Invitation to Collaborate

This award is both an encouragement and a reminder: healthy lighting should not be limited to stricter equipment specifications. Instead, it should evolve toward an approach that integrates:

• Spatial modeling
• Human-centric factors
• Operational verification

Building on existing standards and the efforts of industry organizations, we are eager to work with more partners to address current gaps and turn “good lighting” into a truly replicable and operational system.

06｜Next Steps: Let’s Make “Good Light” a Common Language for the Industry

If you are working on projects in any of the following areas, we warmly welcome collaboration and co-creation:

• WELL / Healthy Building Initiatives
• Healthy Offices
• Healthcare and Educational Spaces
• “Quality Home” Showrooms / Upgraded Turnkey Systems
• Residential Public Spaces and Smart Home / Space Operating Systems (integrating light, thermal comfort, and air quality)

Together, we can turn “good light” into a replicable, operational system and a shared industry standard.

📩 Collaboration & Contact: We warmly welcome you to get in touch through the Lighting Recipe Institute website: www.lightingrecipe.com

We sincerely thank the industry for this recognition — and every individual who believes that “good lighting deserves to be taken seriously.”

Over the past several years, across international forums, standards organizations, and corporate advisory projects, our CEO has consistently emphasized a core message: the next phase of healthy lighting is no longer about technology alone, but about real-world implementation.

The key driver of that implementation is neither manufacturers, laboratories, nor standards bodies, but designers working at the very front line of spatial decision-making.

Building on this belief, in December our CEO partnered with Yunzhiguang (云知光) to deliver the company’s first large-scale, systematized healthy lighting training program specifically for designers. Covering health-based lighting logic, standards verification, and the practical application of the Field Evaluation System (FES) for diagnosing lighting quality in real environments, the program brought together more than fifty designers on site—marking the opening of a new chapter for the industry.

Why Designers Are the Critical Force Behind the Realization of Healthy Lighting

Because every form of lighting that truly changes lived experience must ultimately pass through the hands of designers before it enters homes, hotels, offices, schools, healthcare facilities, and senior living communities.

No matter how advanced the technology, how rigorous the standards, or how refined the products may be, if the design process does not fully grasp the logic of light × people × space × time, healthy lighting will remain confined to presentation slides rather than built reality.

This is what made the course particularly compelling: for the first time, designers approached lighting from a health-first perspective, rather than evaluating it solely in terms of brightness, aesthetics, or cost.

FES: Grounding Every Design Decision in Real Spaces

During this training, the most discussed and widely appreciated tool was the In.Licht® FES (Field Evaluation System), developed by LRS as an on-site evaluation methodology.

Its strong resonance with designers stems from three long-standing pain points in lighting design practice:

1. Laboratory data ≠ real-world experience
2. Calculated drawings ≠ actual human light exposure
3. Product specifications ≠ spatial health performance

The introduction of FES provided, for the first time, a practical and actionable response to these challenges.

Circadian impact of light
Metrics such as m-EDI, EML, and CS are no longer abstract parameters; they become measurable, adjustable, and verifiable behaviors within real spaces.

Visual comfort of light
Glare, uniformity, and task suitability are no longer judged solely by experience or intuition, but evaluated through on-site evidence.

Emotional and behavioral effects of light
Exposure levels across different zones, times, and user groups can be quantified, mapped, and compared, enabling more precise design decisions.

Integrated experience of light × air × environment
In.Licht® allows for the simultaneous assessment of lighting and air quality (PM2.5 / PM10, TVOC, CO₂), as well as temperature and humidity—elevating design thinking from a single lighting system to a holistic living scenario.

It is this three-dimensional view of health that prompted many designers to remark after the course:

“This was the first time I saw light truly relate to people.”
“I didn’t realize that the health of a space could actually be measured, designed, and improved.”
“FES allows us to say, ‘this is healthy,’ instead of ‘it should be good enough.’”

Training in Action: From Theory and Simulation to Real-World Diagnosis

During the training, participants engaged in in-depth discussions around key questions:

• How does light influence human alertness, sleep, emotions, and stress?
• Why are “seeing clearly, sleeping well, and feeling comfortable” the three essential elements of good lighting?
• How should lighting priorities be determined based on spatial tasks and user behavior?
• How can FES be used to establish a diagnostic workflow before design, during design, and after implementation?

When designers began conducting on-site measurements with In.Licht®—inside rooms, along corridors, and in front of façades—many were struck by several discoveries:

• In the same space, exposure levels vary dramatically from one position to another.
• Circadian illuminance does not necessarily come from the brightest luminaires.
• The factors that most strongly affect comfort are often spectrum and distribution, not wattage.
• Air quality shows a strong correlation with perceived lighting comfort.

By transforming subjective impressions into measurable evidence, FES replaces “it feels about right” with “the data shows”—marking a fundamental shift in the industry from experience-driven practice to science-based design.

Why is this training so significant?

Because this is the first time that human-centric lighting (HCL) has progressed from:
“Explaining concepts” → “Explaining methods” → “Explaining scene diagnostics” → “Hands-on tool practice”

This means:
📌 HCL is no longer just manufacturer marketing
📌 It is no longer just standard clauses
📌 It no longer stays only within academic models

Instead, it has truly entered the hands of designers, becoming a practical, implementable service.

Advantages of In.Licht®: Truly Designed for the Real Space

In class, designers most often discuss the unique value of In.Licht®:

1. All-in-One Integration
Spectra, circadian rhythm, flicker, illuminance, color temperature, and air quality—six key dimensions—all part of the real spatial experience.

2. Designed for Actual Space Scenarios
It’s not about “measuring the light,” but about “measuring the light people actually experience.”

3. More Than an Instrument—A Complete Methodology
FES is both a service system and a design language, turning data into actionable design capability.

4. Fully Aligned with International Standards
Circadian logic, flicker logic, and visual task logic from WELL, IES, and CIE can all be verified on-site.

A New Era of Human-Centric Lighting Requires Us to Move Forward Together

After this training, We are even more convinced:
The design industry of the future will be divided into two types of people—
🔹 Those who understand health
🔹 Those who still “only look at brightness”

In.Licht®’s mission is to empower more designers, developers, brands, and operations teams with the ability to “see what’s real”, enabling the creation of lighting environments that are more scientific, human-centered, and beautiful.

Closing Remarks

Thank you to all the designer partners who participated in this course. Your enthusiasm, curiosity, and professionalism have been truly inspiring.

Let’s work together to make light a sustainable, scalable service and create spaces that are genuinely human-centered.
Stop guessing light. Start measuring. Move beyond guesswork—use science to improve health.

Over the past 20 years, the three things we were most often asked for in projects were:

• Make the lighting look good, give the space “character”;
• Ensure illuminance meets standards, with correct Eh values;
• Achieve energy efficiency, with attractive energy reports.

Many designers have mastered this “Look + Eh + Energy” combination—but Human Centric Lighting (HCL) is quietly changing the rules.

Clients are now asking: “Does this lighting support sleep, mood, focus, or vision?”

For professional lighting designers, this is both a challenge and an opportunity for career advancement.

---

1. The Ceiling of Old Rules: Eh and Renderings Are No Longer Enough

Traditionally, a “well-executed lighting design” meant:

• Illuminance calculation: Horizontal illuminance (Eh) on work surfaces meets 300 / 500 / 1000 lx;
• Glare control: UGR within allowed limits;
• Energy control: Power density (W/m²) meets green building or energy standards;
• Renderings: Layered, with contrast, visually shareable.

These remain important, but HCL reminds us: people are not just a point on a lux map—they are a physiological and psychological system.

Typical blind spots:

• Indoor daytime: Eh is sufficient, but vertical eye illuminance (Ev) is too low—people can see, yet feel sleepy;
• Nighttime hotels/high-end residences: high illuminance + color temperature for “luxury” may disrupt sleep;
• Offices: beautiful renderings, but long-term work forces eyes to constantly switch between bright and dark areas;
• Schools/healthcare: designing by “classroom standards” ignores circadian rhythm and emotional recovery.

The challenge: Traditional tools and workflows are designed for “visibility + standards,” not for “how light affects people.”

2. HCL Requires Designers to Do More: From Eh to Ev, From Illuminance to Rhythm

Key terms:

• Eh (Horizontal Illuminance): Lux on horizontal surfaces, e.g., desks, floors.
• Ev (Vertical Eye Illuminance): Lux on the vertical plane at eye level, closer to the light dose the brain actually receives.
• HCL (Human Centric Lighting): Lighting designed around human physiology, cognition, emotion, and health—not just aesthetics or objects.

A conversation on HCL:

Former IALD President Jeffrey Miller once asked:

“You speak of HCL—how is it different from a lifetime of lighting design ‘for humans’?”

At first, I could only vaguely explain it in terms of rhythm, emotion, and health research.
After years of on-site measurements and practice, I now answer:

“You’ve always designed for humans. HCL asks us to go further—not just how bright a space is, but how much light the human eye actually receives (Ev).
When Eh meets task needs and Ev supports rhythm and emotion, that’s truly HCL.”

簡而言之：

• Previously: focus on space, form, style.
• Now: Eh supports tasks; Ev supports brain and body.

Practical HCL Guidelines

1. From Eh to Eh + Ev

• Eh determines if a task is visible.
• Ev determines how much light the brain receives.
• Without Ev consideration: desks may be bright, but people’s brains stay in “evening mode.”

Implementation:

• In hotel rooms, offices, clinics, classrooms: evaluate Ev along typical sightlines.
• Use software + on-site measurements to manage both Eh and Ev.

2. Introduce m-EDI / melanopic concepts

• Different spectra have different circadian impacts.
• 300 lx at 4000K is not equal to 300 lx at 2700K in terms of rhythm.
• Designers should answer:
  • Is there enough circadian stimulus during the day?
  • Is it reduced at night?
  • Does tunable lighting follow this logic?

3. Consider S/P Ratio

• Useful in outdoor or low-illuminance scenarios:
  • Pedestrian areas: maintain visibility at lower Eh with higher S/P spectra;
  • Night tourism/landscape: reduce ecological and circadian disruption while preserving visual storytelling.

3. Five Indoor Scenarios: From “Style” to “Human Timeline”

1. Hotels

• Beyond “looks + Instagrammable”: guide lighting along the full day: check-in → hygiene → sleep → night wake → morning.
• Example:
  • Arrival: slightly high Eh/Ev, neutral or slightly cool;
  • 1–2 hours before sleep: lower Eh, Ev, and color temperature;
  • Night wake: very low Eh + soft guiding light.

2. High-end residences

• Children’s rooms: task lighting meets Eh, Ev protects eyes and rhythm;
• Master bedroom: promote sleep, reduce Ev at night;
• Living/dining: support social, relaxation, occasional work—don’t apply one-size-fits-all.

3. Offices

• Open plan, meeting rooms, focus zones, relaxation areas: tailored Eh/Ev/CCT/contrast strategies;
• Collaboration with HR, ESG, or wellness teams, not just MEP.

4. Healthcare

• Patient rooms: daytime Ev supports alertness, nighttime is soft and non-disruptive;
• Nurse stations: maintain vigilance without overstimulation;
• Rehabilitation: support mood and motivation, not just “brighter is better.”

5. Education

• Classrooms, libraries, dorms, activity areas: design circadian rhythm for focus, rest, and social activity.

Key principle: draw a “human timeline” for each scenario—what state people should be in, and how light helps achieve it.

4. From Indoor to Outdoor: HCL in Urban and Infrastructure Lighting

Outdoor is a key part of daily light exposure—often overlooked.

1. Urban landscapes & night tourism

• Problem: overlit plazas, cold color temperatures, long-term rhythm disruption, ecological impacts.
• Solution: use S/P ratio to maintain visibility while lowering Eh; design Ev at pedestrian eye level; gradually reduce brightness and color temperature at the end of routes (“wind-down”).

2. Tourism lighting

• Beyond storytelling: create a “return-home curve” in lighting.
• Dramatic early scenes, gradual reduction later to prevent physiological overstimulation.

3. Bridges & tunnels

• Already consider “entrance adaptation, mid-section illuminance, glare.”
• HCL adds: reduce fatigue, support circadian rhythm; segment tunnels/bridges with Ev, signage, and glare management.

5. AI + IoT: Making HCL Operational

Design stage: AI can generate multiple “human-centered scenarios,” optimizing Eh/Ev/S-P/m-EDI, freeing designers from repetitive calculations.

Implementation & operation: IoT sensors (occupancy, daylight, temperature, noise, CO₂) allow lighting systems to automatically adjust HCL scenarios, with regular calibration against design values.

Takeaway: AI and IoT don’t replace designers—they empower designers to manage truly “living” lighting environments.

---

6. Conclusion: HCL Is a Professional Upgrade

• Light is no longer just “visibility”—it’s about how it interacts with humans over time.
• Designers must learn: Eh, Ev, m-EDI, S/P ratio, rhythm models; adopt a human timeline; work with AI, IoT, and measurement tools.
• Opportunity: transition from “lighting stylist” to “lighting & wellness experience designer”, engaging clients on sleep, efficiency, brand, and urban nightlife.

Next project challenge: add one page to your design plan:

• Does Eh support tasks?
• Does Ev support circadian rhythm and mood?
• Is your lighting merely “pretty,” or already responsible?

特別感謝佛山照明外貿團隊和佛山照明研究院的邀請，讓我有機會與研發、設計、市場和前線銷售的同仁一起思考照明產業的下一個成長曲線。.

🟩 1.時代已經改變：照明不再只是「製燈」而已“

照明產業的發展已經超越了「製造燈具」這個簡單的範疇。光現在影響著我們的情緒、晝夜節律、工作效率、認知能力和睡眠品質，並逐漸成為建築和空間價值的基礎元素。.

然而，許多傳統照明公司都面臨一個迫切的問題：
當節能紅利達到頂峰時，下一波競爭會從何而來？

出口下滑、價格競爭、產能過剩......這些不只是個別公司的問題，而是整個產業結構改變的訊號。.

在這種情況下，傳統品牌能否實現新的成長，取決於兩點：

1. 策略判斷是否正確
2. 投資是否有意義且能夠建立長期能力

🟩 2.產業現況：機會與挑戰並存

在培訓會上，我與佛山照明外貿團隊分享了幾個趨勢：

1. 全球需求結構正在改變
   買家的期望正在從 「明亮」 → 「好光」 → 「健康、場景化的照明系統」 轉變。’
2. 產業競爭從產品轉移到產品 + 服務
   東南亞產能的提升以及跨國公司的數位能力，意味著中國公司再也無法單靠單一產品來競爭。.
3. 以人為本和健康照明是新的切入點
   真正的競爭不再是誰能生產更便宜的產品，而是誰更了解光如何更好地為人們服務。.
4. AIoT 正在改寫產業分工
   未來的照明公司將類似「專注於光的物聯網公司」。“

🟩 3.從節能到健康、優質照明：能力轉換

這次訓練的核心是要證明：

從節能照明到健康、優質照明，這不僅是「品牌重塑」，更是企業能力的升級。健康照明的未來價值體現在三個方面：

• 健康價值： 改善睡眠、晝夜節律、情緒和視覺表現
• 商業價值： 更有效率的辦公室、更舒適的旅館、更高價值的住宅
• 品牌價值： 從「產品品牌」轉型為「健康生活解決方案品牌“

要真正落實「健康、優質的照明」，企業必須從三個層面進行升級：

1. 升級光源和燈具
   低閃爍、高 CRI 和最佳化光譜構成了基礎。.
2. 開發以空間和場地為基礎的光質評估系統
   “「談論健康照明 」與 「現場測量 」是不同的。In.Licht 的晝夜節律光、視覺平衡、閃爍和光譜度量系統使健康照明變得可測量和可實現。.
3. 從產品轉移到以情境為基礎的解決方案
   教育、辦公室、飯店、老人照護--每種場景都需要「燈光配方」，而不僅僅是更昂貴的燈。.

🟩 4.傳統品牌如何重振雄風？對佛山照明的三點建議

這些建議適用於整個產業，也是會中討論最多的部分。.

建議 1：停止投資於無效的軌道；加倍投資於 「未來能力」“
照明公司真正的「未來能力」包括

• 光健康和晝夜節律照明的知識
• 情境式解決方案研究與應用
• AIoT 控制、感測與平台功能
• 與國際標準接軌 (WELL / CIE)
• 可驗證的現場交付能力（資料驅動）

資源有限-投資於建立長期競爭力的能力。.

建議 2：從「銷售燈泡」轉為「燈泡 + 情境 + 資料」系統價值
未來領先的照明公司將具備三個特點：

• 可量測的產品（光譜、晝夜效應、閃爍、視覺舒適度）
• 可重複使用的方案（教育、辦公室、旅館照明解決方案）
• 資料保留 (In.Licht Well/Pro 裝置的現場資料)

這標誌著從 「製造邏輯」 到 「服務邏輯」 的轉變。“

建議 3：做對的事，而不只是做更多的事
我經常說國內和國外：
“「今天生存，明天茁壯」。”

短期：產品驅動的現金流。.
長期：與 品牌力量 + 技術 + 解決方案.

健康照明既是趨勢，也是能力的門檻。先行者可以建立領先的標準和客戶觀感。.

🟩 5.總結：感謝佛山照明促成此次對話

非常感謝佛山照明外貿團隊和研究院。這是一次傳統品牌與新趨勢的深度對話，代表著業界向前邁進的重要一步。.

健康照明不只是口號，它需要正確的策略判斷、有意義的投資，以及持續的實際能力。.

我希望我們能繼續與更多優秀的公司合作，將「健康、優質的光」帶入更多空間。.

讓光明照亮人們，也照亮我們產業的下一個篇章。.

Lawrence Lin，燈光配方工作室
WELL Light 概念顧問 | Good Light Group 董事會成員

This article is based on the latest data and analysis from the ISA “SSL Industry Report 2025,” combined with our on-the-ground observations and reflections over the past few years in markets such as China, India, and Europe. We want to discuss: as the energy-saving dividend reaches its peak, what will the lighting industry rely on to survive next?

(Photo of Lawrence Lin delivering a presentation on stage at the 2019 DOE SSL R&D Workshop)

1. First, About ISA: Who is Mapping the Global “Ledification”?

ISA (International SSL Alliance) is composed of government departments, industry associations, research institutions, and leading companies from multiple countries. It is one of the most important global collaboration platforms in the field of solid-state lighting (SSL). Since its founding, ISA has accomplished three key tasks:

Bridging: Connecting policy, standards, and industry

• In regions such as China, Europe, and North America, ISA assists governments and standards organizations in aligning SSL technology roadmaps, efficiency targets, and industry realities.
• It participates in and promotes the development and revision of energy-efficiency standards, labeling systems, and energy-saving policies across multiple countries.

Mapping: Providing a “radar and compass” for global SSL development

• Regularly publishes global SSL industry reports and roadmaps.
• Systematically analyzes luminous efficacy limits, cost curves, application scenarios, and policy trends.
• Serves as an important reference for decision-makers, companies, and investors in forming strategy.

Accounting: Clarifying the contribution of energy saving and emissions reduction

• Quantifies the impact of improved lighting efficiency on carbon reduction, reduced electricity demand, and infrastructure pressure.
• Makes “promoting LED adoption” not just a technical choice but an inevitable option in energy and climate policy.

簡而言之：

Without ISA’s decade-plus efforts in bridging, mapping, and accounting, global consensus on replacing traditional light sources with LEDs would not have formed so quickly.

2. Norman and DOE: Turning Good Technology into Global Policy

One of the lead authors of the SSL Industry Report 2025 is the well-known Dr. Norman Bardsley. His role bridging ISA and DOE deserves special attention.

ISA’s Chief Architect

• Longtime chief analyst/advisor at ISA.
• Integrates policies, technological progress, and industry data into a “common language.”
• Enables decision-makers from different countries to discuss the future on the same map.

Key Strategist for DOE SSL Program

• Has participated for many years in the U.S. Department of Energy (DOE) Solid-State Lighting (SSL) Program.
• Helps set target efficacies, cost pathways, technical milestones, and demonstration projects.
• Turns “replacing traditional light sources with LEDs” into a national-level project with a roadmap and timeline.

Translating Technological Evolution into Industry Decisions

• He focuses not only on laboratory limits but also on commercial viability: when can it reach the market? When will costs be acceptable? Which applications benefit first?
• This is why his reports can persuade both the technical community and policy-makers, as well as investors.

---

3. Our Personal Experience: From “Full Spectrum” Skepticism at DOE to Today’s HCL Consensus

Lawrence Lin also has a personal connection with Norman.

In early 2019, at Norman’s invitation, Lawrence Lin attended the DOE SSL R&D Workshop representing LEDVANCE and delivered a keynote titled:

“Towards the Era of Full Spectrum LED Lighting.”

At that time, many were skeptical about “Full Spectrum”:

• Some thought it was merely a marketing term.
• Others questioned why so much effort should be spent on spectral quality under tight efficiency and cost pressures.

Looking back today, Full Spectrum LEDs became one of the key physical enablers for Human-Centric Lighting (HCL):

• Without LEDs closer to the natural spectrum, tunable, and easily measurable and controllable, discussions about circadian rhythm, mood, and visual comfort would have remained confined to labs and PowerPoints.
• For HCL to truly reach schools, hospitals, offices, and urban spaces, there first had to be a “good, well-behaved” light source.

Lawrence Lin has always valued the intense discussions with Norman and DOE colleagues at that meeting. Many of the points that were questioned at the time have since become industry consensus.

From “making LEDs more energy-efficient” to “making light more human-centric,” the bridge between these two was precisely “Full Spectrum + measurable human-factor metrics.”

4. After the “Energy-Saving Campaign” Was Declared Victorious

Over the past twenty years, driven by institutions such as ISA and DOE, global policies, subsidies, and research funding have elevated LEDs to a central position:

• The average efficacy of artificial lighting worldwide increased from about 50 lm/W in 2005 to nearly or over 100 lm/W by 2025.
• Humanity’s “use of light” has almost doubled — longer lighting hours, higher brightness, and more complex scenarios. We have never been more adept at using light than we are today.

However, in 2024–2025, several key signals emerged:

Governments say, “It’s time to step back.”

• Many countries are gradually reducing dedicated SSL funding.
• Relevant international projects are completing their phases — the energy-saving light bulb battle is largely over.

Industry media bows out

• Long-established professional media are either closing or transforming, and the industry focus is quietly shifting from “luminous efficacy and devices” to “applications and scenarios.”

Efficiency rises, electricity use doesn’t drop significantly

• Lighting electricity consumption has not halved despite doubled efficacy; in some years, it even slightly increased. Efficiency gains are outweighed by “more light, larger areas, longer hours.”

Our view:
The “energy-saving light bulb battle” is over. In the next decade, companies focused solely on lm/W will gradually lose influence. The new battleground is: light and humans, light and health, light and spatial value.

---

5. China’s LED Industry: Revenue Up, Profits Hollowed Out

The report’s analysis of China’s LED industry is particularly eye-opening:

• Listed companies focusing on LEDs still see overall revenue growth, but net margins continue to decline, with industry-wide profitability negative.
• Gross margins for packaging and general lighting businesses are low, and capacity utilization has fallen below warning levels.
• Export volumes remain substantial, but unit prices have dropped significantly, with many categories experiencing double-digit declines within a year.

This means:

Volume rises, “value” collapses

• Production lines are running, orders are not few, but net profits are thinning or even turning into losses.

China is the global “LED granary,” not the price setter

• Upstream in modules, light sources, and fixtures, the true leverage for project influence and brand premium lies in systems and solutions.

Price wars have exhausted traditional profit models

• Competing only on wattage, materials, and cost, without shifting to “good light + good space + good systems,” leads only to exhaustion.

Our judgment:
If Chinese lighting companies continue to view the world through “add more lines, make more molds” in the next five years, today’s financial reports may already be the most “presentable” pages.

---

6. Application Scenarios: Where Is the Real “Second Growth Curve”?

The ISA report analyzes mainstream applications separately: automotive, horticultural, roadway, displays, UV, NIR, and smart lighting. Here are a few critical for Chinese companies:

1. Horticultural Lighting: From Hype to Financial Reality

• The global LED horticultural lighting market is still growing, but growth is becoming rational.
• Several vertical farm projects in Europe and the U.S. suffered losses or bankruptcy — the accounting isn’t about fixtures, but the entire business model.

Summary:

• Fully artificial-light vertical farms have extremely high building, energy, and equipment costs. Without clear crop positioning and supply chain design, profitability is difficult.
• More promising are high-value crops like leafy greens, herbs, microgreens combined with renewable energy and precise control.

Conclusion:
Chinese companies in horticultural lighting should not just sell “lights,” but provide an integrated solution of crops + algorithms + energy + business model.

2. Automotive Lighting: Technical High Ground, Not a “Lifesaver”

• The automotive LED device market continues to grow, led by a few international brands.
• Technologies such as ADB adaptive high/low beams and dynamic taillights continue to evolve, but regulations, OEM platforms, and reliability requirements make this a slow-paced, high-entry-barrier field.

My view:
Automotive lighting is suitable for building technical and brand prestige but is unlikely to solve large-scale overcapacity in the short term. A more pragmatic approach is to reverse-apply automotive-grade optics and reliability thinking to human-centric lighting in buildings and cities.

3. Micro-LED and Displays: A Marathon of Capital and Time

• Some leading micro-LED companies saw revenue growth and narrowed losses from 2022–2024, but in 2025, inventory, exchange rates, and demand fluctuations caused sharp revenue drops and widening losses.

For most lighting companies:
Micro-LED is more like a “ticket to technical influence” rather than a “main business savior” in the next 3–5 years.

---

7. Human Factors and Health: HCL Becomes a Hard Metric

In recent years, from DOE to IES, CIE, and then WELL and LEED, everyone has been pursuing the same goal:

• Transform “good light” from an adjective into measurable, deliverable engineering language.

The report highlights three aspects in the “Light and Health” section:

Circadian Impact

• Expert consensus recommends daytime melanopic EDI at the eye level to support stable circadian rhythm and nighttime sleep.
• Under constraints of efficiency and glare, achieving full compliance using only electric light sources is not easy.

Blue Light and Photobiological Safety

• Typical residential lighting poses minimal skin risk; the main concern is high blue light output and retinal risk for specific sensitive populations.
• This requires finer classification and more empirical research.

Glare and Temporal Light Modulation (TLM)

• The point-source nature of LEDs and certain dimming methods complicates glare and flicker issues. Headaches, fatigue, migraines, and photosensitive epilepsy can be associated with improper TLM characteristics.

This echoes Full Spectrum LED:

• Without better spectral carriers, HCL cannot be truly implemented.
• Full Spectrum + measurable human-factor metrics is the essential bridge from concept to engineering practice.

Our judgment:
The next industry reshuffle will not favor the cheapest LEDs but those who can clearly define, implement, measure, and deliver human-factor and health outcomes.

---

8. Smart Lighting: From “Connected Streetlights” to “Urban Sensing Infrastructure”

ISA makes important observations in smart lighting:

In China:

• Thousands of medium and large smart lighting companies exist; many SMEs participate in subsystems and projects.
• Indoor and outdoor smart lighting shipments continue to rise.

Globally:

• Smart streetlight installations steadily increase; multiple cities achieve 50–70% energy savings using LED + intelligent control, often with payback faster than expected.

Our observations:

• The “financial logic” of smart lighting is proven: energy savings + O&M reduction + carbon reduction + data value is reflected in urban financial and operational data.

Chinese companies should avoid two traps:

1. Being only a “hardware supplier”: delivering many nodes but outsourcing city operations, data, algorithms, and services.
2. Treating smart lighting as a “one-off weak current project”: after handover, only short-term project profits remain, with no long-term operation or data accumulation.

Real opportunity:
Deliver integrated solutions of good light + good control + good algorithms + good operation, connecting human-centric lighting, energy savings, smart cities, and healthy buildings into a network.

---

9. Next 5–10 Years: Three Directions We See

1. “Good Light” Becomes a Moat, Not an Extra Cost

• Standards are evolving: IES, CIE, WELL, etc., are integrating health and circadian metrics into standards and certifications.
• Client awareness is shifting: from “replace LEDs to save energy” to “how much is lighting worth for employee health, efficiency, and brand experience?”

Recommendation:

• Supply chain companies should include photobiological safety, circadian photometry, TLM metrics in specs, not just CCT/CRI.
• Brands and system integrators should tell stories using human-factor metrics + project data, not only lumens, watts, and price.

2. Upgrade from “Product Logic” to “Space + People + Algorithms” Logic

• Future competition is not: “My current-generation fixture is 10% cheaper than the last.”
• It is: “I help your building / campus / city optimize energy use, maintenance, human efficiency, and brand value while ensuring health and experience.”

Recommendation:

• Organize product lines by scenarios: office, education, healthcare, hospitality, elderly care, industry, urban renewal.
• Each scenario requires measurable, deliverable, and reusable human-factor lighting formulas and dimming strategies.
• Make measurement and verification part of the solution: vertical illuminance, melanopic EDI, TLM, SVM, DGP, etc., must be measurable on site and presented in reports.
• Use a data loop for long-term operation: not just turnkey delivery, but continuous optimization according to seasons, schedules, and populations.

3. Chinese Companies Must Move Beyond “Exporting Fixtures”

• Current landscape: China is a major producer of LED chips, packaging, modules, and fixtures, and a key supplier for smart lighting hardware and platforms.
• However, China’s voice in global health lighting standards, spatial design influence, and human-factor research is still limited.

Recommendation:

• Actively participate in international standards and alliances (IES, CIE, GLG, WELL) not just by attending meetings but bringing data, cases, and solutions to discussions.
• Turn Chinese projects into international benchmarks: organize excellent campuses, hospitals, campuses, and cities into bilingual white papers and case libraries.
• Showcase that good light + good space + good systems are successfully implemented in China.
• Upgrade the “internal skills” of price competition into the “combined force” of an ecosystem: from chips, packaging, modules, fixtures, systems, algorithms, measurement, standards to operation, forming a Healthy Light Ecosystem Alliance to go global together rather than individually.

---

Conclusion: Turning Point Is Here — Different Choices, Different Futures

The 2025 SSL Industry Report by ISA, under the comprehensive analysis of Norman and other experts, gives a very clear signal:

• The era of “more energy-efficient lamps” is over.
• The industry is moving from the “energy-efficiency era” to the “Good Light Era”: good circadian rhythm, good mood, good spatial experience, good city nightscapes, good hospital wards, classrooms, factories, farms…

At this turning point:

• Some will continue competing on every LED chip and fixture;
• Others will raise their sights to focus on standards, scenarios, ecosystems, health, and city-scale lighting environments.

Those who endure will see a new world; those left behind often think it was just another “bad market cycle.”

If you are considering: “What should we move from ‘selling lights’ toward next?”, feel free to continue the discussion in the comments.

---

Sources and Copyright Statement

• Some data, charts, and judgments in this article are quoted from ISA’s SSL Industry Report 2025, whose lead authors include Dr. Norman Bardsley and other international experts.
• Any interpretation or extended commentary represents the author’s personal views; in case of discrepancies, refer to the original ISA report.
• Original data and charts are copyrighted by ISA and the respective authors.
• This article is intended for industry exchange and academic discussion only, not for commercial resale or republishing.
• If the original report authors or ISA have any concerns about citation, please contact the author, and adjustments will be made promptly.

In the previous article, We wrote an invitation addressed to design tool providers such as DIALux and Cohoom:

If they do not embrace HCL, designers will find it difficult to truly realize the idea of “designing light that supports a person throughout their entire life.”

However, even if designers are equipped with better tools and are able to create more scientifically grounded HCL solutions, if control systems only support basic functions like “on/off, dimming, and scheduling,” all of this remains theoretical, confined to presentations.

In this article, we want to have a serious discussion with lighting system providers about several key issues:

• Why most existing system logic is, in fact, not suitable for HCL;
• What core capabilities a system that genuinely supports HCL must have;
• How lighting system providers can, within 1–2 years, evolve from being “controller suppliers” into “light environment operation platforms”;
• and what LRS can do together with you.

I. Today’s System Logic Is Still Stuck in the Era of “Channels + Scheduling + Energy Saving”

Let us first describe, honestly, what control logic looks like in many typical projects today:

• Circuit grouping → wall panels → Scene 1 / 2 / 3 / All On / All Off;
• Add a few sensors: lights on when people arrive, lights off when they leave;
• Add some scheduling: lights on at the start of work, off after hours;
• At most, add an extra “energy-saving mode” or “demo mode.”

All of this certainly has value. However, when you place it within an HCL context, three fundamental problems immediately emerge.

1. The system does not know “who this light is for.”
An elementary school classroom, an open-plan office, a night-shift nurse station, and a senior living apartment bedroom are, under current system logic, often treated simply as “rooms with slightly different illuminance levels,” rather than as environments serving people with entirely different circadian and physiological needs.

2. The system does not know “which act of the day it is.”
Many systems can be set to “turn on at 8 a.m. and off at 10 p.m.,” but they lack a true time-based scene continuum, such as:
morning activation / late-morning focus / afternoon sustain / evening wind-down / pre-sleep dose reduction / safe nighttime movement.

As a result, so-called “HCL scenes” are reduced to:
brighter during the day, dimmer at night; cooler or warmer CCT—without a scientifically designed lighting-dose plan.

3. The system does not know “how far the current light is from the target.”
Most systems are only responsible for “outputting a dimming value according to a scene,” yet they have no awareness of:

• The approximate Eh / Ev at critical points;
• Whether EML or m-EDI meets the intended targets;
• or whether flicker and contrast remain within safe and comfortable ranges.

Once luminaires age or space usage changes, the system has no self-calibration capability—let alone any form of closed-loop control.

In other words, most lighting systems today are, in essence, still operating as “smarter switches,” rather than as health-oriented infrastructure that manages light dosage and supports human biological rhythms.

II. What Core Capabilities Must a System Truly Supporting HCL Have?

Based on LRS’s experience in projects and on-site measurements, a system designed for HCL and LaaS (Light as a Service) needs, at a minimum, the following layers of capability:

1. Upgrade from “channel control” to a “scene engine.”
During design and commissioning, the discussion should no longer revolve around “Channel 1 at 80%, Channel 2 at 40%,” but instead focus on:

• 的 target Eh / Ev / CCT / contrast ranges for a given space;
• The corresponding user groups and activities (office work, education, nursing, recovery, sleep, etc.).

Internally, the system may still operate through channel-level calculations, but externally it should provide:
metrics-based scene definitions, rather than a collection of percentage values.

2. Built-in time axis: a day is not a single scene.
The system should support configuring time-sequenced scenes for each space, for example:

• 07:00–09:00 Morning activation
• 09:00–12:00 High-efficiency focus
• 12:00–14:00 Gentle transition
• 14:00–18:00 Sustained focus
• 18:00–20:00 Soft relaxation
• 20:00–22:00 Pre-sleep dose reduction

For users, what they see is a daily lighting curve, not a set of isolated scene buttons.

3. Built-in health-oriented scene templates and guidelines (even in simplified form).
Similar to design tools, systems can fully incorporate scene templates, such as:

• Children’s study room: daytime study / evening homework / pre-sleep reading;
• Open-plan office: day shift / night shift / overtime / cleaning;
• Nurse station: night shift / handover / emergency;
• Senior bedroom: morning wake-up, post-nap, return from outdoor walk, pre-sleep relaxation, nighttime movement.

These templates do not need to be highly complex at the outset, but they should at least include:

• Recommended Eh / Ev ranges;
• Recommended CCT ranges;
• Recommended time windows and transition logic.

The presence of such templates significantly lowers the barrier to implementing HCL solutions and enables system providers to offer replicable, scalable solutions to designers and clients alike.

4. Establish a Data Closed Loop Across “Design → Commissioning → Measurement → Optimization”

A health-oriented lighting system should be capable of the following:

Import target values from the design stage.
Receive target Eh / Ev / CCT / EML and related parameters from DIALux, Revit, or the provider’s own design tools.

Display “target vs. current output” during commissioning.
Allow commissioning engineers to view target values and actual output side by side while tuning scenes in real time.

Feed on-site measurement data back into the system.
Support importing measured data from devices such as In.Licht Ultra / Pro (even via simple CSV files);
automatically generate “measured vs. design” comparison charts and optimization recommendations.

Enable long-term monitoring and alerts.
Conduct periodic re-measurements in critical areas (e.g., ICUs, nurse stations, key office zones).
When the lighting environment deviates significantly from target values, the system can issue prompts, such as:
luminaire aging? scenes manually altered? changes in shading or daylight strategies?

This is the foundation that allows LaaS to operate sustainably over the long term and to improve continuously.

III. From “Selling Hardware” to “Operating Light Environments”: System Providers Can Create an Additional Business Line

Many lighting system manufacturers have shared similar concerns in recent years:

• Margins on controllers, drivers, and gateways continue to shrink;
• Competition is intensifying and products are increasingly commoditized;
• Systems are expected to “support everything,” yet it becomes harder and harder to articulate a clear value narrative.

HCL and Light as a Service offer a timely opportunity for both business and brand upgrading.

1. At the solution and bidding stage: offer “health-oriented lighting solution packages.”
Rather than merely stating “supports DALI / KNX / ZigBee / BLE Mesh” and similar protocols, system providers should be able to present, within their proposals:

• HCL scene libraries tailored to different building types and user groups;
• Corresponding system logic, control algorithms, and day-to-day operational recommendations;
• Indicator frameworks aligned with healthy building certifications and ESG reporting.

2. At the implementation stage: provide “commissioning and validation services.”
By collaborating with designers, consultants, and teams such as LRS, system providers can offer value-added services that combine health-oriented lighting commissioning and on-site measurement validation.
This elevates their role from a one-off system integrator to a light environment delivery owner.

3. At the operation stage: provide “annual light environment checkups” and subscription services.
For key clients (hospitals, corporate campuses, schools, hotels, etc.), providers can offer:

• Annual or quarterly light environment re-measurements and reports;
• Analysis of usage behavior and optimization potential based on system data;
• Assistance in adjusting HCL strategies when clients update space functions or work–rest schedules.

For system providers, this means adding a second revenue engine:
beyond one-time project-based revenue, a compounding stream of service and subscription revenue.

IV. Where Can System Providers Start in the Next 12–24 Months?

There is no need to attempt everything at once. However, if you agree that HCL and LaaS represent the direction of the next 5–10 years, I would recommend that system providers at least consider the following steps:

Establish a small HCL task force.
Bring together product, R&D, and marketing teams to clearly define the kind of health-oriented lighting narrative the system product line aims to deliver.

Select 2–3 priority scenarios as initial entry points.
For example: office + healthcare + education, or office + hospitality + senior living.
Rather than attempting to address every industry immediately, focus on a few key scenarios and make them detailed, solid, and well-explained.

Co-create scene libraries and time-axis templates with HCL specialists.
Partner with teams such as LRS to jointly define default scene packages 和 health-oriented lighting parameter ranges based on research and on-site measurements.

Introduce basic time-axis and HCL scene logic into existing systems.
Without disrupting existing user habits, add higher-level logic entry points such as “circadian mode” or “health mode.”

Build a minimum viable closed loop with design tools and measurement devices.
Start with a simple, practical workflow:
import target values from the design stage → system execution → on-site commissioning → measurement feedback → report generation.

Select 1–2 flagship projects to validate and tell the story well.
Work with designers, owners, and HCL consultants to create demonstrator projects.
Use real data and user feedback to clearly articulate the differentiation and value of a health-oriented lighting system.

V. What Can LRS Do Together with Lighting System Providers?

LRS (Lighting Recipe Studio) has consistently positioned itself as a bridge between scientific research × design thinking × product and system implementation:

We are deeply involved in research and field measurements related to HCL, light and circadian rhythms, and light and emotion.
We also collaborate on projects with designers, lighting brands, system providers, and healthy building teams worldwide.
Through tools such as In.Licht Ultra / Pro and the FES (Field Evaluation System) methodology, we strive to translate complex science into frameworks that are designable, measurable, and operable.

If you are:
a manufacturer developing or upgrading your own intelligent lighting systems;
looking to make health-oriented lighting, HCL, or LaaS a core axis of your product roadmap;

LRS would be glad to:

• Serve as an HCL consultant and content co-creation partner, working with you to define:
• Scene templates, time-axis strategies, and health-oriented lighting parameter ranges;
• Integration pathways with design tools and measurement devices;
• and bridges between healthy building standards, ESG frameworks, and brand storytelling.

Aesthetic lighting is something systems have supported for many years.
Responsible lighting still requires system providers and designers to work together to embed it into the everyday reality of every space.

If you are willing to evolve your system from a “smarter switch” into a long-term steward of the light environment, then now is, indeed, an excellent starting point.