Competence Library - Heatsinks

Thermally, more surface area is usually good, but weight, centre of gravity, cost, adapter load and design can become problematic. An oversized heat sink can create mechanical disadvantages even though it adds thermal margin. In track luminaires, weight, leverage, adapter load and design must be assessed just like temperature.

High temperature can affect LED package, phosphor, silicone and optics, reducing colour stability and channel balance. Colour shift does not always appear immediately, but can build up over operating hours. In demanding applications with tight binning or tunable white, thermally driven channel shift becomes visible early.

COB holders position the module, may provide contacts and support the optic. the heat sink must simultaneously secure the thermal path. The holder provides positioning and often electrical contact, while the optic defines the light path. The heat sink must provide enough space and safe support without stressing the optical assembly.

Constant voltage is typical for strips, constant current for modules and COBs. in both cases the heat to be dissipated matters. Constant voltage systems are often combined with 24V strips, while constant current systems are common for COBs and modules. For the heat sink, the heat to be dissipated matters more than the name of the electrical supply method.

Distributors should clarify whether customers need a profile, heat sink, COB accessory, TIM or complete luminaire solution. Distributors can help customers by distinguishing between profile, heat sink, TIM, COB accessories and complete luminaire solution. Asking about power, space and installation location prevents many wrong orders.

A rough calculation uses the thermal budget, permitted temperature difference divided by dissipated power, minus the partial resistances up to the heat sink. The thermal budget shows how much temperature rise is still allowed between ambient and LED. The resistances of module, TIM and contact area are subtracted from this value to select the heat sink realistically.

Series processes need clear TIM dosing, defined screw torque, clean surfaces, inspection points and sample measurements. Series quality comes from repeatable assembly and clear inspection points. Defined TIM quantity, controlled screw sequence, clean storage of modules and sample measurements on real assemblies are part of this.

Whether insulation is required depends on LED module, MCPCB, protection class, driver and TIM and must be decided from data sheet and luminaire test. Whether insulation is required depends on protection class, driver, module construction and TIM. An electrically safe solution must not unnecessarily worsen heat flow, so insulating pads always need thermal evaluation.

For linear modules, watts per metre, continuous profile contact, profile mass, cover and temperature along the full length matter. With linear modules, heat is distributed along the length, making profile contact and mounting surface very important. Covers, tight furniture channels and high watts per metre can quickly overload a profile that first seemed sufficient.

The LED module should sit flat and clean with suitable TIM. screws must be tightened evenly according to instructions. Before assembly, contact surfaces must be clean, flat and free from burrs. After fastening, the module should sit evenly, because tilted loading can reduce both heat transfer and mechanical lifetime.

Thermal effects often change with runtime and temperature, while control issues change with dimming level, profile, bus or wireless state. Thermal causes usually change slowly with temperature and runtime. Control issues respond more directly to dimming level, address, wireless connection or profile change, so both paths should be tested separately.

Measurement is taken at the marked Tc point with a suitable sensor, realistic ambient, highest relevant output and after thermal stabilisation. The measurement should use a firmly attached sensor and realistic operating conditions. Only after the temperature has stabilised can it be judged whether the luminaire operates within the approved range.

Architectural lighting often has to integrate cooling surfaces invisibly into housings, profiles, façades or ceilings without blocking heat dissipation. Architectural lighting often hides technology in profiles, façades, coves or ceilings. The cooling surface must not only be aesthetically integrated, but still keep air contact and a safe heat path.

In constant current systems, driver current, LED voltage, efficacy and Tc limit define the thermal load of the module. The set current together with LED voltage defines electrical power. If a COB or module is driven harder, heat sink, Tc point and driver must still remain within limits as one system.

Selection depends on heat dissipation, LED data sheet, permitted Tc or Tj temperature, ambient conditions and the real luminaire assembly. First, the expected heat at the selected drive current and the permitted module temperature are clarified. Then the mechanical check follows with hole pattern, contact area, mounting orientation and open airflow.

For 24V strips or modules, watts per metre, profile contact, cover, furniture integration and PWM duty load are decisive. In 24V systems, thermal questions often arise along the entire strip length. Key factors are watts per metre, adhesive contact, profile mass, cover and the actual installation in furniture or architectural profiles.

COB LEDs concentrate high power on a small area, so a short thermal path, good flatness, suitable TIM and stable fastening are especially important. With COBs, a short thermal path is especially important because many chips sit close together on a small area. The selection must therefore consider data sheet, Tc point, holder, TIM and optic at the same time.

Casambi influences control, profiles and radio placement, but heat is still determined by LED power, driver and installation situation. Casambi belongs to the system layer and affects profiles, dimming behaviour and radio position. It becomes thermally relevant when switching devices or dimmers sit inside the luminaire head or a wrong profile creates unexpected continuous load.

Dimming often reduces average power, but the luminaire must still be designed for the highest relevant continuous operating state. At reduced brightness, average heat often drops, but scenes, boost functions and long operating periods still matter. The design should cover the worst sustained condition, not only the usual dimming level.

A driver in the same housing raises internal ambient temperature and can stress both the LED heat sink and its own derating limits. A driver inside the luminaire head warms the local ambient and can make LED cooling harder. External mounting or thermal separation can help when space is small or long full load operation is expected.

Human centric lighting uses dynamic scenes and long daily profiles, so typical and maximum channel loads must be checked. Dynamic daylight profiles create changing channel loads and long operating patterns. The design should therefore check typical scenes and maximum states instead of measuring only one colour temperature.

The higher the electrical power and power density, the more heat must be removed through contact area, material, surface area and airflow. More power does not always create a perfectly linear temperature rise, because geometry and air movement contribute. Still, surface area, material mass and heat transfer requirements increase clearly when current and power density rise.

Mounting orientation changes natural convection, heat build up and fin performance. free air laboratory values are therefore not automatically transferable. Natural convection follows the movement of warm air and reacts strongly to rotated or recessed cooling surfaces. A free air value can therefore be much worse in a downlight, furniture channel or track luminaire.

Simulation helps compare hotspots, airflow, material options and geometries early, but it must be validated by measurements. Simulation makes temperature distribution and airflow visible early. It does not replace measurement because material tolerances, assembly quality, dust and real mounting positions are often simplified in the model.

On site, mounting orientation, airflow, insulation, driver setting, dimming profile and actual ambient temperature must be checked. During commissioning, the real installation should be compared with the approved design. Insulation, cables, covers, dimming levels and driver settings can change the thermal balance more than installers may expect.

The test must run until LED module, heat sink, housing and driver have reached nearly stable temperatures. The required duration depends on mass, power, installation space and airflow. Large housings respond slowly, so a short test often shows temperatures that are too low.

Thermal margin prevents production variation, dust, higher ambient temperature or closed installation spaces from immediately causing limit violations. Thermal margin is useful because projects rarely match laboratory conditions exactly. Higher room temperature, ageing, dust and production variation can otherwise make a calculated solution too tight in daily operation.

A complaint needs data on installation, ambient, runtime, dimming profile, measurement points, product version and possible changes to the assembly. A clean evaluation separates product defect, assembly error and changed use conditions. It needs measurements, photos, runtime, driver data, dimming profile and a check against the approved assembly version.

In modular track systems, luminaire head, heat sink, adapter, joint, driver and track must be assessed together. In modular track systems, the full assembly of head, adapter, joint, driver and track matters. A.A.G. Stucchi can be relevant in this context as a supplier of track and adapter components, while thermal approval of the luminaire head remains separate.

During replacement, contact area, TIM, Tc limit, current, optic compatibility and fastening of the replacement module must be checked again. A replacement module can fit electrically and still behave differently thermally. Drive current, Tc limit, contact area, optic position and new TIM should therefore be checked again after replacement.

Changes to LED, driver, heat sink, coating, TIM or hole pattern should be documented as engineering changes and reassessed. Every engineering change can alter the heat path, even when it looks mechanically small. Different surfaces, new pads, changed screws or alternative LED modules should always be documented and thermally approved.

Thermal paste should only fill unevenness, so it must be applied thinly, evenly and on the intended contact area. Paste is not a substitute for a flat surface, but should close fine irregularities only. A thick layer acts as insulation, can leak sideways and leads to poorly repeatable production results.

Useful records include luminaire, LED, driver, current, dimming state, ambient, measurement point, runtime, orientation and sensor position. Good documentation makes later complaints and series approvals traceable. Measurement point, ambient temperature, drive current, dimming state, runtime and photos of the installation are especially important.

IEC 62031 concerns LED modules and shows that modules may be safely operated only within their intended thermal conditions. LED modules may only be used within their intended limits. The standard therefore makes clear that thermal integration belongs to safe use and should not be treated as an afterthought.

Junction temperature, or Tj, describes the temperature in the active semiconductor region of the LED and is the central thermal value for reliability and light quality. This value is usually not measured directly in the finished product, so manufacturers provide reference points and models. In practice, the approved luminaire must stay within the derived temperature limits over time.

LES describes the light emitting surface of a COB. smaller LES areas enable narrow optics but often increase thermal power density. A small light emitting surface is attractive optically because narrow beams become possible. Thermally it often means more power on less area, so COB, holder, optic and heat sink must be checked together.

Photobiological safety primarily concerns optical radiation, but temperature influences flux, spectrum, optics and ageing. Optical safety is primarily defined by flux, spectrum and beam distribution. Temperature can change these quantities because it affects LED efficacy, chromaticity, materials and optics.

System compatibility means optical, mechanical, electrical and thermal aspects work together, not merely that one component mechanically fits. System compatibility means that a part works in the complete luminaire assembly. A heat sink may fit mechanically and still be unsuitable when optic, driver, airflow or installation environment restrict heat dissipation.

Thermal resistance in K/W describes how much temperature difference rises per watt of heat and how efficiently heat flows through a path. A lower value usually indicates better heat flow when the test conditions are comparable. For heat sinks, mounting orientation, air movement and ambient temperature must also be considered, otherwise catalogue values look too optimistic.

Zhaga D4i standardises smart luminaire interfaces. additional sensor or communication modules change space, airflow and internal ambient temperature. Smart interfaces move sensors and communication closer to the luminaire. This makes space, covers and local ambient temperature more important, even though the main heat still comes from LED module and driver.

Hot luminaires can stress insulation, cables, furniture, ceiling material or touchable surfaces and must be checked in the finished assembly. Fire safety is especially important for recessed luminaires, furniture, insulation and tight ceilings. High temperatures can age materials, stress insulation or heat surfaces beyond acceptable limits.

Outdoor luminaires combine heat dissipation with IP protection, UV exposure, corrosion, sunlight and sensor or communication modules. Outdoor luminaires must remove heat while resisting moisture, UV, corrosion and dirt. Sealed housings, sunlight and smart nodes change the thermal environment and must be assessed together.

Retail spotlights need high output, precise optics and long operating hours in compact heads, creating strong thermal stress on COB and driver. Retail spotlights combine high output, narrow beams and long opening hours in compact heads. In track applications with Stucchi related components, adapter load and electrical interface must be checked in addition to spotlight cooling.

A heat sink is a thermally conductive component that absorbs waste heat from an LED module, spreads it and releases it to ambient by convection and radiation. What matters is not only the visible mass of the part, but the heat path all the way to ambient air. A robust design combines thermal calculation, mechanical contact and measurement in the real luminaire assembly.

Active cooling uses fans, blowers, heat pipes or similar systems to remove more heat from a small space at high power density. Active solutions can enable compact high output luminaires, but they add noise, wear and further failure risks. They should therefore be used only when passive surface area, weight or space are not sufficient.

An MCPCB is a metal core printed circuit board that spreads heat from the LED package better than standard FR4 and conducts it toward the heat sink. The metal core shortens the thermal path from the LED package toward the heat sink. Even an MCPCB still needs a good interface, because adhesive layers, screws and intermediate materials strongly affect total resistance.

Track spotlights combine compact heads, high power, weight limits, joints and adapters, so cooling must be evaluated as a complete assembly. Track spotlights have little space and still need to combine output, optics, joint and adapter. In systems around A.A.G. Stucchi, adapter and track load capacity should be assessed separately from thermal approval of the luminaire head.

Derating means an LED module or driver should no longer operate at full output under high temperature, unfavourable ambient conditions or protection limits. Derating protects components from sustained excessive thermal stress. The design should not rely only on protection functions, but keep normal operating conditions within approved limits.

Hospitality luminaires should be quiet, compact and premium looking. passive, low maintenance cooling is therefore often especially important. Hotels and restaurants value silent operation, compact form and premium surfaces. Passive cooling is often attractive, but it must be confirmed with real temperatures when installed in ceilings, furniture or decorative housings.

Passive cooling uses material, surface area, fin geometry and natural air movement without using fans or active moving systems. It is popular because it is silent and low maintenance. It needs enough surface area and open air paths, because a covered or insulated installation can reduce its effect significantly.

Conduction transfers energy through solids, convection releases heat to air, and radiation emits heat from the surface as infrared energy. All three effects work together inside a luminaire. Conduction brings heat to the heat sink, while convection and radiation determine how quickly it leaves the luminaire body.

A heat sink is primarily designed for heat removal, a luminaire housing protects and supports, and an LED profile mechanically guides linear modules or strips. A profile or housing can contribute thermally when contact area, wall thickness and exposed surface are suitable. The name of the part alone does not prove that it is approved as the main heat sink.

LED drivers have their own temperature limits and protection functions. their heat must be assessed together with LED module and heat sink. The LED driver has its own temperature points and protection behaviour. If it is integrated into the same luminaire head, its losses can raise LED temperature and also limit driver lifetime.

The Tc point is a manufacturer defined measurement point used to evaluate thermal stress of an LED module or control gear in the real assembly. The point is important because it allows repeatable evaluation in prototypes, production and service. It should not be replaced by arbitrary housing measurements, because other positions can show different temperatures.

Thermal interface material, or TIM, fills microscopic unevenness between LED module and heat sink and reduces air gaps with high thermal resistance. The material improves contact only when it matches the surface, pressure and required electrical insulation. Too much paste or an overly thick pad can make heat transfer worse instead of better.

Industrial luminaires need thermal margin for high hall temperatures, dust, long runtimes, vibration and difficult cleaning. Industrial environments stress luminaires through dust, high temperatures, vibration and long operating hours. A robust heat sink therefore needs not only surface area, but cleanable geometry and margin for contaminated conditions.

The interface controls the driver. thermally, the maximum LED power and driver temperature in real operation are what matter. The interface itself usually produces little heat, but it defines how the driver operates the LED module. With 0?10V and 1?10V, the maximum power that can still occur despite dimming must be checked.

Fins increase surface area, but they work well only if air can circulate between them and they are not blocked by dust or installation conditions. Fins need spacing, height and an orientation that allows air movement. Very narrow fins can perform poorly in natural convection because air stagnates and dust collects more easily.

Strips need continuous contact, clean adhesive surfaces, sufficient profile mass and free heat dissipation despite covers or installation channels. The adhesive backing of a strip does not replace thermal assessment of the profile. If contact is interrupted or a cover traps heat, local overtemperature and visible ageing can occur.

Hole pattern, contact area, tolerances, electrical insulation and fastening must match the LED module, otherwise air gaps or uneven pressure occur. The mechanical interface determines whether the LED module sits flat with defined pressure. Even small tolerance errors can create air gaps that matter more thermally than a slightly larger heat sink.

LES size, reflector, lens, holder, build height, screws and airflow influence optical quality and thermal safety at the same time. Optic, module and cooling influence one another through height, distance, fastening and airflow. An optically suitable combination is fully approved only after the temperature has also been checked in the real assembly.

Planners should ask about ambient temperature, installation type, lifetime target, surface temperature, dimming profile, driver location and maintenance. Planners should not select luminaires only by lumen output and optics. Ambient temperature, installation type, operating hours, maintenance, dimming profile and reachable surface temperature should be discussed early.

Touchable heat sink surfaces must be evaluated according to material, application, contact duration, mounting height and standards framework. Touchable surfaces must stay safe while still releasing heat. The assessment depends on material, mounting height, usage, environment and the standards framework of the finished luminaire.

DALI and D4i do not cool, but drivers, diagnostics, operating states and additional electronics in the luminaire head can become thermally relevant. These protocols do not change the physics of the heat sink, but they influence operating states, diagnostics and driver placement. Especially with D4i, added data and power points can help interpret thermal conditions in the system.

Track adapters support and power the luminaire. they are usually not the main heat sink, but can influence space, weight and airflow. The adapter defines contact, locking and mechanical load, but it is usually not intended as the main cooling surface. In Stucchi related track solutions, the thermal test of the spotlight or module therefore remains a separate task.

Cables must not block fins, vents or sensors and must be insulated for the local temperature. Cables can block airflow or additionally insulate warm areas. Cable material and connectors also need to be rated for the local temperature to avoid slow developing contact problems.

Tunable white luminaires have multiple channels. thermal load changes with mixing point, dimming level and operating profile. Multi channel luminaires change their thermal load depending on mixing point. Warm and cool channels should be tested in the worst sustained condition, because a balanced dimming value does not automatically create the highest temperature.

The surface determines how well heat is released by convection and radiation. area, fins, emissivity and contamination are decisive. Fins, anodising, colour and contamination have a noticeable effect in practice. A large surface helps only when air can reach it and covers or dust layers do not insulate it.

Dust on fins and fans reduces heat dissipation. cleaning must not damage coating, gaskets, electronics or optics. Dust reduces the effective surface and can narrow air paths between fins. Cleaning intervals are especially important in retail, industry and gastronomy, where grease and dirt adhere faster.

Brown areas indicate overtemperature, material ageing, poor profile contact or too much power per metre. Brown areas warn of sustained high local temperature or material ageing. Lower power per metre, a better profile, cleaner contact and a cover check often help.

If Tc is exceeded, measurement, current, TIM, contact, heat sink, airflow and installation state must be checked and corrected. First the measurement itself must be checked because wrong sensor positions lead to wrong conclusions. Then current is reduced, contact improved, airflow opened or the heat sink and luminaire design are adapted.

Purchasers should compare not only price and size, but also Rth, tolerances, documentation, surface finish, hole pattern and supply stability. In purchasing, Rth, hole pattern, surface finish, tolerances and documented test conditions matter more than unit price alone. A cheap heat sink becomes expensive when rework, complaints or a new approval are required.

PWM reduces average power depending on duty cycle, but can remain thermally critical at high duty, wrong profile or unsuitable load. PWM changes duty cycle and therefore average power, but not every thermal peak automatically disappears. At high duty cycles or with unsuitable loads, the luminaire should be checked as if it were at full load.

Office luminaires operate for many hours and need stable output, reliable drivers and low maintenance in ceilings or linear systems. Office luminaires run for many hours and should deliver even light with little maintenance. Suspended ceilings, linear profiles, integrated drivers and sensors that warm the inner space can become thermally critical.

Thermal pads are useful for defined thickness, electrical insulation, clean production or tolerance compensation, but they can have higher Rth. Pads are practical when defined thickness, electrical separation or a clean assembly process is required. Their higher thermal resistance must match the power level, otherwise the production benefit becomes an operating disadvantage.

A housing is sufficient only if material, wall thickness, contact area and exposed surface safely transfer heat to ambient. A housing can take over this function when it is conductive, large enough and well connected. Decorative or thin walled housings should be checked carefully to see whether design surfaces really work as cooling surfaces.

Active cooling becomes relevant when passive surface area, weight or space are not sufficient for the desired output. This is mainly relevant at high power density, very small form factors or high ambient temperature. Before choosing active cooling, larger surface area, lower current or better airflow should still be evaluated.

Lower LED power can be more sensible than a larger heat sink when size, weight, surface area or safety limits are constrained. Sometimes lower output is the cleanest technical solution. When space, weight, surface area or touch temperature are limited, lower drive current can be more reliable than an ever larger heat sink.

Important values include Rth, permitted dissipation, dimensions, material, mounting conditions, LED Tc limit, driver derating and test conditions. Rth, test conditions, maximum Tc temperature, mounting notes and derating data belong together. One value alone is not enough because the real heat path consists of several parts and contact points.

Common mistakes include dirty surfaces, too much paste, missing pad, uneven support, incorrect torque and blocked airflow. Such mistakes are often invisible at first, but later appear as high Tc values or hotspots. Old paste residues, damaged pads, dirty profiles and unevenly tightened screws are especially critical.

Modular luminaires need coordinated interfaces between LED module, heat sink, driver, optic, housing, adapter and installation environment. Modular systems work only when mechanical, electrical and thermal interfaces fit together. In Stucchi related track and adapter environments, electrical compatibility should be checked together with weight, space and heat removal o

Materials should conduct heat well, fit mechanically, resist corrosion and suit the manufacturing route, such as extrusion, die casting or housing design. Besides conductivity, machinability, corrosion resistance, weight, surface and cost matter. In professional luminaires, the best single material is often less important than the best balance of thermal behaviour and series production.

The relevant framework is the safety and evaluation context of the complete luminaire, not one isolated heat sink standard. Heat sinks are normally evaluated through the luminaire and its components. The decisive points are permitted temperatures at LED module, driver, wires, materials and touchable surfaces.

LM 80 and TM 21 link lumen maintenance to defined test temperatures and make real operating temperature decisive for lifetime claims. These methods make lifetime statements meaningful only when real operating temperature is known. Good thermal design keeps the luminaire close to the conditions on which the projection is based.

Housing and LED are at different points in the thermal path. a warm housing can indicate either good or poor heat transfer. A warm surface can show that heat is being removed well from the module. It can also mean that heat is not leaving the luminaire, so Tc measurement and ambient conditions must be assessed together.

Warm ceiling voids reduce the temperature difference to ambient and often restrict convection at heat sink and driver. Ceiling voids are often much warmer than the room below. This reduces the usable temperature difference, while insulation and tight cutouts further restrict airflow at the heat sink.

LEDs do not convert all electrical input into light. a relevant share becomes heat, affecting junction temperature and therefore lifetime, flux and colour. Without controlled heat removal, temperature and ageing rise faster than the data sheet selection may suggest. Thermal management therefore belongs in the concept phase of a luminaire and not only in later troubleshooting.

If heat cannot reach the heat sink because of air gaps or wrong TIM, the LED module stays hot while the heat sink may seem deceptively cool. The best heat sink cannot help if heat does not enter it. A seemingly cool heat sink beside a hot LED module is therefore a clear sign of a poor thermal interface.

In the project, higher ambient, insulation, ceiling voids, different orientation, dust or covers can greatly worsen the laboratory condition. Laboratory tests are often performed in free air under controlled conditions. In projects, ceiling voids, insulation, dust, mounting angle and nearby heat sources can change the thermal situation significantly.

A heat sink gets too hot when too much heat is generated or airflow, contact, TIM or ambient conditions are worse than planned. The cause is often not the heat sink alone, but the combination of power, contact and installation environment. A useful check starts at the Tc point and compares the measured value with current, airflow and mounting condition.

Flicker after warm up points to thermal protection, driver derating or temperature dependent contact and load problems. If flicker starts only after warm up, driver derating and thermal protection functions should be checked. Dimming profile, load compatibility and contacts must be checked in parallel because similar symptoms can also be electrical.

Fast lumen loss can result from high junction temperature, excessive current, poor cooling or optical ageing. Fast lumen loss often indicates excessive operating temperature or aggressive drive current. Dirty optics and aged materials should also be checked so thermal and optical causes remain separated.

Delayed shutdown often results from driver overtemperature, LED overload, undersized heat sink or blocked installation conditions. Delayed shutdown matches overtemperature, overload or protection logic in the driver. The fault can be narrowed down by observing temperature curve, input current and restart behaviour during cool down.

Local hotspots arise from air gaps, warped boards, poor adhesion, uneven current distribution or locally poor contact. A local hotspot usually points to poor contact or uneven heat generation. Comparative measurements at several points help distinguish between assembly error, module issue and trapped air.

Aluminium combines good thermal conductivity, low weight, machinability and economical production as extrusion, die casting, machined part or housing component. Aluminium is a good compromise of thermal performance, weight and cost in many luminaires. The actual geometry remains decisive, because a poorly shaped aluminium part can cool worse than a larger freely ventilated design.

IEC 60598 matters because luminaires must not create impermissible temperatures on components, materials, wires or touchable surfaces. The standard considers the safety of the finished luminaire and therefore also temperature limits. For developers, cooling is not only an efficiency topic, but part of electrical and mechanical safety.

Torque defines contact pressure. too little pressure leaves air gaps, while too much can damage the module, ceramic or holder. Correct torque creates defined contact force and protects the module at the same time. Too little pressure leaves air in the interface, while too much pressure can damage ceramics, PCB or holder.

Museums require colour stability, high colour rendering, precise accent lighting and quiet operation, making thermal margin important. Museum lighting requires stable colour, high colour rendering and often narrow accent beams. Generous thermal margin helps reduce colour drift and avoids adding unnecessary heat from the luminaire near sensitive exhibits.

Data sheets apply under defined conditions. real luminaires include different airflow, mounting, TIM, production variation and ambient temperature. Data sheet values are created under defined conditions and rarely cover every project situation. Real measurements show whether assembly, airflow, production variation and ambient really match the calculated design.

Covers, films, insulation or cable bundles reduce convection and radiation and can thermally change a previously approved luminaire. A cover can make a heat sink behave almost like it is insulated. Protective films, decorative elements or cables should therefore not remain where the luminaire must release heat to air.