Fixed LEDs in lamps- how long do they last?

The lifespan of LEDs: Comparison and advances

Service life is generally specified in operating hours, which is a common method of determining the longevity of light sources. LEDs are known to last significantly longer than conventional incandescent or halogen lamps.

Manufacturers typically specify a service life of around 20,000 to 50,000 hours. These impressive figures are the result of technological advances made in LED development. To understand the significance of these operating hours in an everyday context, a simple

calculation

can

be made: An LED lamp that is used for an average of 3 hours per day would last for approximately 18 years with a service life of 20,000 hours. If the same lamp is operated for 50,000 hours, it could last up to 45 years. This is a huge advantage over conventional incandescent lamps, which last only about 1,000 hours on average, and halogen lamps, which last about 2,000 to 4,000 hours.

Comparison with conventional light sources

The long service life of LEDs is a major factor in their increasing replacement of incandescent and halogen lamps. While a conventional incandescent lamp burns out relatively quickly and needs to be replaced frequently, the use of LEDs significantly reduces maintenance costs. This reduction in replacement frequency is not only practical, but also saves costs in the long run.

Technological advances and efficiency

The impressive lifespan of LEDs is the result of numerous technological advances. LEDs use semiconductor technology that enables a more efficient conversion of electricity into light compared to the traditional methods of light emission in incandescent bulbs. While an incandescent bulb produces light through the heating effect of a tungsten filament, losing a lot of energy as heat in the process, LEDs operate cooler and more efficiently.

Long-term reliability

In addition to their long service life, LEDs also offer consistent light quality throughout their entire operating life. With many conventional lamps, light output decreases over time, whereas LEDs tend to maintain their brightness over a much longer period.

The failure rate is also lower with LEDs, making them a reliable choice for applications where continuous lighting

is required.

is crucial, such as in industrial environments or public institutions.

Economic and ecological advantages

The long service life of permanently installed LEDs not only brings economic benefits through reduced maintenance and replacement costs, but also ecological advantages. Less frequent replacements mean less waste and lower resource consumption. This makes LEDs a more environmentally friendly option that can contribute to a sustainable lighting strategy.

"To extend the life of permanently installed LEDs, ensure that they do not overheat. Permanently installed LEDs are sensitive to heat, and high temperatures can drastically reduce their service life. It is therefore important that the LEDs are properly cooled, e.g., by using heat sinks or fans."

Degradation of LEDs: Causes, Effects, and Countermeasures

Degradation is a term used in many technical and scientific fields and generally describes the process of deterioration or gradual decline in material properties, performance, or efficiency.

 

In relation to LED technology, degradation refers to the reduction in light output and efficiency of LEDs over time. This process is inevitable, but its speed and extent can be influenced by various factors.

Degradation in LEDs

In LEDs, degradation mainly occurs in the form of a decrease in luminous efficacy. This decrease is often referred to as lumen maintenance and is expressed as a percentage of the original luminous efficacy. A typical degradation value could be, for example, 70% of the original brightness after 50,000 operating hours, often referred to as L70. This means that after this operating time, the LED still has 70% of its original Brightness delivers.

Causes of degradation

1. Thermal stress: Excessive heat is one of the main reasons for LED degradation. Although LEDs are more efficient than traditional light sources, they still generate heat that must be dissipated. Poor heat dissipation can lead to overheating, which damages the LED materials and reduces light output.
2. Electrical stress: Heavy or fluctuating electrical loads can affect the service life and efficiency of LEDs. A constant and stable power supply is crucial for minimizing degradation.
3. Environmental conditions: Moisture, extreme temperatures, and chemical influences can attack the materials of the LED and its associated components, leading to faster degradation.
4. Material quality: The quality of the materials used has a significant impact on the rate of degradation. High-quality LEDs made from robust materials generally show slower degradation compared to inferior products.

Effects of degradation 

Degradation directly affects their performance and efficiency. As degradation increases, not only does brightness decrease, but color shifts can also occur, affecting light quality. This can be particularly critical in applications where consistent lighting conditions are required, such as in industrial environments, medical facilities, or art galleries.

Measures to reduce degradation

1. Good thermal management: Implementing effective cooling systems or techniques can keep the temperature of the LEDs low, thereby slowing down degradation.
2. High-quality materials: Using high-quality LEDs and components can significantly reduce the rate of degradation.
3. Stable power supply: A constant and clean power supply prevents electrical overloads and protects the LED components.
4. Protection from environmental influences: Suitable housings and protective coatings can protect LEDs from harmful environmental influences and extend their service life.

Factors and methods for calculating LED lifetime

LED lifetime is usually specified in operating hours and describes the period during which the LED can maintain a certain performance or brightness. This calculation is based on several factors and tests designed to ensure that the LEDs function reliably under real-world conditions. Here are the most important steps and factors that are taken into account when calculating LED lifetime:

1. Lumen maintenance: The lifetime of an LED is often defined as the time until the luminous efficacy has fallen to a certain percentage of its original value. Typical measurements are:

1. L70: The time until the LED reaches 70% of its original luminous efficacy.
2. L80: The time until the LED reaches 80% of its original luminous efficacy.

For example, L70=50,000 hours means that after 50,000 hours of operation, the LED still provides 70% of its original brightness.

2. Test conditions: LEDsare tested under standardized conditions to obtain consistent and comparable results. These tests include:

1. Temperature: LEDs are tested at different temperatures to measure their performance under realistic operating conditions.
2. Operating current: The current at which the LEDs are operated is kept constant during testing.
3. Environmental conditions: Tests take into account environmental conditions such as humidity and air pressure.

3

. Accelerated life tests: Since it is impractical to test LEDs over their entire lifetime, accelerated tests are used. These tests increase the operating temperature and current to accelerate the aging process. The results of these tests are then extrapolated to estimate the lifespan under normal conditions.

4. Failure rate and reliability: In addition to luminous efficacy

,

the failure rate of LEDs is also taken into account. This refers to the Probability that an LED will fail completely due to a technical defect. Statistical methods such as the Weibull distribution are used to model the failure rate over time.

5. Manufacturer specifications and certifications: Manufacturers often specify guaranteed lifespans based on their internal tests and models. Certifications from independent testing institutes can provide additional assurance that the specified lifetimes are reliable.

Example of a calculation 

A manufacturer could test an LED at 25°C room temperature with an operating current of 350 mA and find that after 10,000 hours, the LED still retains 95% of its original brightness.

 

Using mathematical models and accelerated testing at higher temperatures, it could be extrapolated that under normal conditions, the LED would still have 70% of its brightness (L70) after 50,000 hours.

Factors influencing the actual service life of LEDs

The actual service life can be influenced by a variety of factors that go beyond simply specifying the operating hours. Switching cycles, the number of operating hours, and the ambient temperature play a significant role here. These factors can significantly influence the performance and longevity of LEDs and should be taken into account when selecting and installing LED lighting.

1. Switching cycles

Definition and influence: Switching cycles refer to the number of times an LED is switched on and off. Each LED has a limited number of switching cycles it can handle before its performance is affected.

Impact on lifespan: Frequent switching on and off can cause thermal stress in the LED as it heats up and cools down each time. These thermal cycles can strain the internal components and lead to premature failure. LEDs are generally more robust against switching cycles compared to conventional incandescent bulbs. Nevertheless, extremely frequent switching on and off, for example in applications such as motion detectors or flashing lights, can shorten the service life.

Manufacturer specifications: Many manufacturers state that their LEDs are designed for a certain number of switching cycles. This can range from a few thousand to several million cycles, depending on the quality and design of the LED.

2. Number of operating hours

Definition and influence: The number of operating hours refers to the total time an LED spends in the switched-on state. This is the primary factor that determines the service life of LEDs and is typically specified by manufacturers.

Impact on service life: The service life of an LED is often specified in terms of lumen maintenance, e.g., L70 (the time until the LED reaches 70% of its original light output). A longer operating time means a higher cumulative load on the LED components. LEDs that are operated continuously for long periods of time generally have a longer service life compared to those that are switched on and off frequently.

Practical example: An LED that operated for an average of 3 hours per day has a significantly longer expected service life than one that is operated 24 hours per day. This means that the same LED will last longer in a household than in an industrial application, where it may be lit around the clock.

3. Ambient temperature

Definition and influence: The ambient temperature is the temperature of the air around the LED during operation. LEDs are sensitive to high temperatures, as these can directly affect their performance and service life.

Influence on service life:

High temperatures: Operating LEDs at high ambient temperatures can lead to overheating. Overheating accelerates the degradation of LED materials and reduces light output more quickly.

Low temperatures: Low temperatures are generally less harmful to LEDs and can even extend their lifespan. LEDs operate more efficiently and generate less heat at cooler temperatures.

Heat management: Effective heat dissipation is crucial to maximizing the lifespan of LEDs. This can be achieved through the design of the LED luminaire, heat sinks, and other passive or active cooling methods.

Manufacturer specifications: Most manufacturers test their LEDs at standardized temperatures, typically 25°C. These tests provide baseline data, but actual lifespan may vary when LEDs are operated in warmer or colder environments.

Reasons for LED failures and options for replacing LED lamps

LEDs can break, even though they have a much longer service life than conventional incandescent and halogen lamps. Various factors can cause an LED to fail:

Overheating: One of the most common causes of LED failure is overheating. If heat is not dissipated effectively, the internal components of the LED can be damaged. This can be caused by inadequate heat management, insufficient ventilation, or high ambient temperatures.

Electrical overload: Voltage spikes or current fluctuations can damage the electronic components of the LED. This can be caused by faulty power supplies, improper wiring, or electrical interference in the power grid.

Quality issues: Inferior LEDs or poor workmanship can also lead to premature failure. High-quality LEDs from reputable manufacturers generally have a longer service life and are less prone to defects.

Mechanical damage: Physical impacts such as shocks, vibrations, or improper handling can damage LEDs. The connections and solder joints inside the LED are particularly sensitive.

Degradation: Even though LEDs operate reliably over long periods of time, they are still subject to a natural aging process. The light output gradually decreases and color changes may occur. Over time, this can lead to the LED being considered "broken" even though it is still functioning.

Can LED lamps be replaced? 

Whether and how LED lamps can be replaced depends on the design of the luminaire and the type of LED. There are basically two main types of LED lamps: replaceable LED light sources and permanently installed LED luminaires.

Replaceable LED bulbs

1. Easy replacement: Many LED lamps are designed to directly replace conventional incandescent or halogen lamps. These LEDs have standardized bases (e.g., E27, GU10) and can be easily replaced by screwing or plugging them into the existing socket.
2. Advantages: Replacement is easy and does not require any special tools or expertise. In addition, defective or outdated LEDs can be replaced quickly and inexpensively. be replaced.

Permanently installed LED lights

1. Complexity: Fixed LEDs are generally more difficult to replace because they are integrated into the luminaire. This often means that the entire luminaire must be replaced if the LEDs fail.
2. Advantages: Fixed LEDs enable more compact and efficient designs. They often offer better heat dissipation and longer service life because they are specifically optimized for the respective luminaire.

Five tips for extending the life of your LED light bulbs

1. Ensure good heat dissipation

Why it's important: Overheating is one of the main causes of premature LED failure. Effective heat dissipation can keep the temperature of LED bulbs low and extend their lifespan.

How to implement: Use luminaires that are specifically designed for LEDs and have good heat sinks or ventilation systems. Ensure that LED lamps are installed in well-ventilated areas to facilitate heat dissipation. Regularly clean dust and dirt from heat sinks and ventilation slots to maintain heat dissipation efficiency.

2. Ensure a stable power supply

Why it's important: Voltage fluctuations and electrical overloads can damage the internal components of LEDs and shorten their service life.

How to implement: Use LED-compatible dimmers that ensure a steady power supply and do not affect the service life of the LEDs. Install surge protection devices to protect the LEDs from sudden voltage spikes. Ensure that the electrical installations in your home or business are proper and safe.

3. Avoid frequent switching on and off

Why it's important: Every time an LED is switched

on

or off, it is exposed to thermal stresses that can affect its service life.

How to implement: Avoid switching LEDs on and off unnecessarily often. Leave them on if you are only leaving the room for a short time. Use motion detectors and timers to optimize the switching on and off of LEDs and reduce the number of switching cycles. For areas where frequent switching on and off is unavoidable, choose LEDs that are designed for many switching cycles.

4. Consider environmental conditions

Why it's important: Extreme temperatures, high humidity, and harsh environmental conditions can affect the performance and lifespan of LEDs.

How to implement: Install LEDs in environments that are within the manufacturer's recommended temperature range

.

Avoid using LEDs in humid or corrosive environments unless they are specifically designed for this purpose (e.g., IP-rated LEDs for outdoor use ). Protect LEDs from direct sunlight and other extreme weather conditions.

5. Choose high-quality LEDs and accessories

Why it's important: High-quality LEDs and components generally offer better performance and a longer service life.

How to implement: Invest in LEDs from reputable manufacturers that are known for their quality and reliability

.

Look for certifications and seals of approval that confirm the quality and service life of the LEDs. Only use compatible power supplies and drivers that are specifically designed for the respective LEDs.

Conclusion – How to do everything right!

The service life of LED light sources can be significantly extended by taking a few simple measures. Good heat dissipation, a stable power supply, avoiding frequent switching cycles, suitable environmental conditions, and choosing high-quality products are crucial. By following these tips, you will benefit from long-lasting, efficient, and reliable LED lighting that saves costs in the long term and protects the environment.

If you are still undecided about how you want to implement your lighting, please feel free to make an appointment with the lighting designers at skapetze® for a personal consultation and the development of an individual lighting concept.

You are also welcome to visit our lighting studio in Simbach am Inn.

If you already have a specific idea of what the lights in your home should look like, we can help you turn that idea into reality – our in-house workshop makes it possible.