LED Pool Lights and Heat Generation

LED Pool Lights and Heat Generation

LED pool lights are widely used in the underwater lighting industry. Although the LED chip is a cold light source and the luminous efficacy is much higher than traditional incandescent lamps and other hot light sources, LED pool lights can still generate a lot of heat when in use. This article will look at the heat generation and heat dissipation of LED pool lights.

Why do LED pool lights get hot?

LED lights convert electricity into light with over 90% efficiency, the rest is wasted in various conversion and transmission processes. Most of this wasted electricity converts into heat, causing the LED pool light to heat up.

Are LED pool lights afraid of heat?

LED chips are sensitive to temperature. In order to dissipate the heat smoothly, LED pool lights have heat dissipation devices inside the light body. If the quality of the LED pool light is poor or the working environment is too hot, the LED pool light may suffer from the following problems due to its inability to dissipate heat properly :

Damage to the LED Chips

When the PN junction temperature is too high (typically over 125°C), the physical properties of the encapsulating material change and the coefficient of thermal expansion increases rapidly. This may lead to LED failure.

Reduced Lifetime

High temperatures can cause LED chips light decay, which is one of the main causes of LED lighting product lifetime. The lighting industry often defines the lifetime of an LED as the time it takes for an LED chips to reach 70% of its brightness. Overheating accelerates the rate of light degradation of LED chips, which is irreversible and can seriously reduce the life of LED pool lights.

LED pool light produced light decay
The LED pool light on the right has significant light decay

Reduced Light Output

As the temperature increases, the light output of the LED chips decreases.

Colour Shift

Increased temperatures can cause a slight colour shift in the luminescence of the LED pool light, affecting the lighting effect and comfort of the pool.

Increased Failure Rate

High temperature environments can increase the failure rate of LED pool lights, as LED chips and other electronic components degrade faster at high temperatures. Some LED pool lights are faulty in design and assembly and are more likely to fail or stop working when exposed to high temperatures.

How do LED Pool Lights Dissipate Heat?

The internal temperature of the lamp body becomes very high after the LED pool light has been working for some time.

LED pool light works in underwater environment. During operation, the water temperature in the environment is much lower than the temperature inside the lamp body. The heat conduction device inside the lamp body conducts excess heat from the lamp body to the water to suppress the high temperature inside the lamp body.All heat dissipation of the LED pool light is designed to better conduct heat away from the inside of the lamp body.

The following lists several common thermal designs used in LED pool lights :

Metal Substrates

Aluminum substrates for LED pool lights

Metal substrates are the main thermally conductive component of LED pool lights. Aluminium has excellent thermal conductivity and most LED pool lights use aluminium substrates.

Thermally Conductive Spacers

Thermal spacers assist in the heat dissipation of the electronic components within the pool light and also act as insulation to prevent short circuits in the pool light.

Metal Housing

Stainless steel pool light housing

The housing of the LED pool light is completely sealed to be completely waterproof. This means that heat from inside the lamp body must exchange with water through the housing. The thermal conductivity of the material used for the housing affects the heat dissipation of the LED pool light.

The thermal conductivity of metal far exceeds that of plastic. A metal pool light of the same design has a better heat dissipation capacity than a plastic pool light.

The difference between high temperature resistant pool lights and ordinary pool lights


Heat resistant pool lights have proven in numerous tests during the design phase that their construction is more conducive to heat dissipation.


high temperature resistant pool light and ordinary pool light

While some common pool lights still use plastic housings, heat resistant pool lights generally have metal housings. In addition to the more common stainless steel, some heat-resistant pool lights have housings made of brass. On average, the thermal conductivity of copper is 401 W/(m K)2 while that of stainless steel is 17 W/(m K)3. Both materials have excellent thermal conductivity.


The thickness of the aluminium substrate for normal pool lights is 1mm, whereas the substrate for heat resistant pool lights is generally 3mm thick. 3mm substrates have a much higher thermal conductivity than 1mm substrates for the same material.

Assembling LED pool light
A worker assembles a 1mm thick aluminum substrate for a common pool light

Some heat resistant pool lights even use copper substrates which further increases the thermal conductivity of the pool light.

When do I need a heat resistant pool light?

Hot springs pool

Hot springs pool Lighting

Not only the design and materials used influence the heat dissipation capacity of LED pool lights, but also the temperature of the working environment. If the water temperature is too high, it greatly reduces the efficiency of heat transfer within the lamp body. As a result, ordinary pool lights are not suitable for use in hot spring pools. This can cause LED pool lights to deteriorate more quickly and may even damage them before their brightness severely reduces.

Heat resistant pool lights have been developed for these high temperature applications such as hot springs pool. Their excellent thermal design improves heat transfer efficiency from the inside of lights to the outside. This prevents overheating inside lights.

Looking to extend the actual life of your pool light

The theoretical service life of LED chips is over 50,000 hours. This experimental figure was obtained when the working environment was at a stable temperature of 25°C (77°F) and heat dissipation was in an ideal state. However, this is almost impossible to achieve in actual use.

In summer, the sun exposes some outdoor pools for long periods of time and raises the pool water temperature, affecting the heat dissipation of the LED pool lights.

High temperatures cause accelerated light degradation of the LED chips. This is one of the main reasons why some LED pool lights have a shorter lifespan. Heat-resistant pool lights have better heat dissipation properties than regular pool lights. This can greatly extend their actual lifespan. If you want a more durable pool light, it is recommended to choose a good quality heat resistant pool light.


In summary, heat generation is a major factor affecting the performance and lifetime of LED pool lights. To improve heat dissipation, LED pool lights use various thermal designs. Heat resistant pool lights have stronger heat dissipation design and capability than ordinary pool lights. They are suitable for high temperature applications such as hot springs pools.

WAKING Lighting is a professional LED pool light manufacturer. They supply both regular and heat resistant pool lights to meet different customer needs. If you are interested in their products or want to know more about heat dissipation of LED pool lights, you can contact us.

Are you looking for a professional underwater light supplier? Contact us now!

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