Just like any product that is meant to be used outdoors, lighting fixtures are affected by the surrounding weather conditions. While rain might be the most common threat associated with weather, cold and warm temperatures also poses a threat to the performance of a lighting fixture.
Consequently, people who are in the process of buying outdoor lighting fixtures need to be aware of how their lights perform in different ambient temperatures. In other words, they need to pay attention to the operating temperature range of the fixtures they are considering.
As a LED lighting supplier with vast experience within the industry, we’ve helped thousands of customers to find outdoor luminairies tailored to their specific needs and requirements. One of the most common questions we get when helping customers is whether their lights will work in very cold temperatures.
In this article, we'll discuss how LEDs perform in both cold and warm temperatures which will clarify why LEDs are to prefer when it comes to installing lights in outdoor settings.
Do you really need to consider the temperature?
The first question to ask when contemplating whether a fixture is suitable or not is: will it work outdoors?
In most cases, the answer would be yes. Broadly speaking, our lighting fixtures operate in temperatures between -40 to 120 F°. Therefore, if you live anywhere in the United States, you can rest assured that your LED lights will work in an outdoor setting as the average temperatures are well within that range.
Average Temperatures in the U.S
Despite of these good news, LEDs may still be affected by certain temperatures which may have an impact on their performance. After all, the very city you’re from might register hot temperatures during the day and below freezing temperatures during the night, causing thermal stress on your product.
So then how are they really affected by cold or warm temperatures, and are there certain temperatures you should avoid?
How LEDs perform in cold temperatures
One of the most well-known advantages with LED lighting is that it performs well in cold temperatures. The main reason for this is because it relies on an electrical driver to function.
Truth is, LEDs actually thrive in cold temperatures.
Owing to the fact that LEDs are semiconductor light sources that produce light when an electric current flows through them, they remain unaffected of cold ambient temperatures and are able to turn on instantly.
Furthermore, LEDs work best in cold temperatures because less thermal stress (changes in temperatures) is put on the diodes and driver. In fact, studies show that when installed in cold applications, LEDs rate of degradation reduces and their lumen output improves.
How LEDs perform in hot temperatures
When LEDs were first introduced to the market, they featured shoebox-style casings and would overheat very quickly because of the lack of ventilation. To prevent this from happening, manufacturers started installing fans inside LED fixtures, but this only encouraged mechanical failures.
New-generation LEDs have heat sinks that help prevent heat-related lumen depreciation. They channel the excess heat and keep it away from the LEDs and the driver. Some luminaires include a compensatory circuit that regulates the current through the LEDs to ensure continuous light output in different ambient temperatures.
But like most electronics, LEDs tend to underperform when operating at higher-than-expected temperatures. During long periods of high ambient temperatures, LEDs can overwork which may decrease their expected lifetime (L70). High ambient temperatures result in high junction temperatures, which can enhance the deterioration rate of the LED junction element. This makes the lumen output of a LED light to drastically decrease at a faster rate than it would at lower temperatures.
However, the rate at which the lifetime of the LED starts to significantly decrease because of ambient temperatures are not common. Only if you know your luminaires will be exposed to high temperatures over long periods of time is it worth looking into how it may affect your choice of lighting.
How do other types of lighting compare?
Compared to other lighting alternatives, LEDs most commonly has the widest operating temperature range and is most often least affected by warmer and colder ambient temperatures. The reason for this is simple, LEDs operate with an electrical driver as opposed to other alternatives who rely on techniques that unintentionally produce a lot of excess heat.
Here’s a brief overview of how the alternatives work and how it relates to their weakness to operate in colder or hotter temperatures:
Incandescent bulbs have a tungsten filament in a glass enclosure. When an electric current passes via the filament, it heats it to a temperature, causing it to produce light. When installed in a cold environment, incandescent lights generate too much heat (up to 90%) and become very inefficient. It takes longer for the bulbs to heat up and produce light.
High Intensity Discharge
High intensity discharge generate light by passing an electric arc through a gaseous combination of vaporized metal halides and mercury. As temperatures drop, less vaporized gas is available in the arc tube of a high intensity discharge lamp. This causes a rise in the open circuit voltage needed to initiate the arc tube, until it gets to a point where the lamp cannot start.
A CFL has a tube containing a small amount of mercury vapor and argon. When an electric current is driven through the tube, the lamp generates invisible ultraviolet light, exciting a fluorescent coating (phosphor) on the tube’s interior which then produces visible light. Compact fluorescents require a starting temperature between 14°F and 104°F for their reaction process to begin. When temperatures are lower than this (14°F), they may fail to start.
In short, LEDs provide the best option when it comes to choosing lighting for your outdoor setting. As long as the operating temperature is considered, most LED lights will function properly.
Whether installing the fixtures in hot or cold temperatures, LED lights will work as expected. Only in very high temperatures may the luminaires be affected and precautions should be made to minimize a decrease in lifetime.
How do your outdoor lighting setting look like? Have you noticed an effect by cold or hot temperatures? Use the comment field below and let us know.