Outdoor LED lights usually work in harsh and complex working environments: temperature, ultraviolet rays, humidity, rain, dust, chemical gases and other climate factors. All these factors combined can significantly affect the light attenuation of LED chips. Designers should take all these environmental factors into account when during the design of outdoor LED lights.
Shell and radiator designed as a whole to solve the LED cooling problem is an appropriate method. Normally, LED manufacturers prefer to use aluminum or aluminum alloy, copper or copper alloy and other alloys that with good thermal conductivity.
Radiator is a crucial part of LED lamps. The shape, size, heat dissipation surface area of it must be well designed. Small radiator will make the lamp work in high temperatures, affect the luminous efficiency and life time. Large radiator need to use a lot of materials, increase the cost and weight, declining the product competitiveness. Appropriate LED radiator design is essential. Radiator design has the following parts:
- Make clear of the cooling power that LED lights need.
- Some parameters that radiator design needed: specific heat of the metal, thermal conductivity of the metal, chi resistance, thermal resistance of heat sinks, thermal resistance of ambient air.
- Heat dissipation type: air convection radiator, strong wind cooling section, heat pipe, as well as other heat radiation ways. From the cost comparisons: air convection radiator cost least. Heat pipe and cooling jet cost the most.
- Make sure the maximum operating temperature (ambient temperature plus the permitted temperature rise)
- Calculate the volume of the cooling area. Determine the shape of radiator.
- Combine LED lamp body and radiator to a complete lighting fixture. Take simple indoor lighting tests: more than 8 hours constant work; at room temperature: 39℃–40℃. Calculate the average working temperature, see if it meets the cooling requirements. If normal condition is not met, related parameters are necessarily to be reset.
- Radiators and lampshades should be waterproof, dustproof. Rubber pad / rubber mat can be used between lampshade and radiator to prevent aging. Stainless steel bolts are used as waterproof / dustproof devices. By above four points, and plus related regulations for outdoor lighting applications and roadway lighting standards. All these are basic knowledge that outdoor lighting designers must be obtained.