LED Light Bar Cooling - Keep Your 4x4 Lights Working For Longer!
If you've been looking at any kind of LED lighting, whether it's lightbars, spots, work lights or even a high powered flashlight, you've probably seen some mention of cooling. If you're more familiar with old-style lamps you might be wondering about this. If so, you need our handy guide to LED cooling. By the time you've read this you'll know why LEDs need cooled and how manufacturers go about it.
Conventional light bulbs produce light in about the simplest way possible; the filament inside them gets very, very hot. LEDs are a lot more sophisticated. They're electronic components, and each one has a semiconductor chip on it. When you pass current through it in the right direction electrons combine with charged particles in the chip and release photons, which are basically particles of light. This is a lot more efficient than just heating up a thin wire, so as well as using less energy in total LEDs also release a higher percentage of their energy as light than a normal bulb does. You might be wondering why efficient LEDs need cooling when an old work light can bet by with a stamped tin shield. That's a good question. The answer is that it's because they're electronic components. If your computer overheats the processor will slow down and start suffering errors; eventually it will fry itself. LEDs are the same.
In fact LEDs work best at around -30°C. That's not a lot of use to most people, but luckily they still work pretty well at normal temperatures, too. Think about the temperature a light bulb can reach, though. If LEDs get that hot you're going to start having problems. There are several problems that will surface. Some will annoy you. Others will cost you money.
As the temperature of an LED light rises the light output will start to fall. That can be a serious problem if you're relying on a lightbar to get through some difficult ground. The quality of the light will also change. A lot of science goes into getting white light LEDs to produce a useful clear light that isn't either too yellow to show up much or blue enough to potentially cause eye damage. As the temperature rises the properties of the semiconductor chip change, and so does the colour of the light. Finally, running LEDs at high temperature reduces their working life by up to 75%; over time all LEDs gradually lose brightness, and heat accelerates the process. It also massively increases the risk of them suddenly failing.
That's probably enough to show that heat in an LED light is a bad idea. Now let's look at how designers get rid of it. It's possible to install fans or even water cooling systems, but the most effective way is to simply use the casing as a heat sink. That saves power and means there are less things to go wrong. LEDs radiate their waste heat from their base, so that makes it easy to conduct it away from the electronics and into the casing. Aluminium is a great conductor of heat, so using an aluminium casing will kill two birds with one stone. For maximum efficiency it's best to use a machined or extruded casing with ribs on the outside. The ribs increase the surface area and radiate the heat into the atmosphere more quickly. Top quality LED lights like those from Rigid Industries use this system.
When we review LED lights cooling is one of the things we pay attention to, especially with higher powered lightbars and spotlights. We know how important proper cooling is. If you've read this far now you do, too.