LED grow lights are becoming increasingly popular for indoor gardening. They offer many advantages over traditional lighting systems such as longer lifespans, lower energy consumption, and higher efficiency. But one of the most important aspects of LED grow lights is their lifespan. In this article, we will discuss the characteristics that determine the lifespan of LED grow lights and how to get the most out of them.
The light output from all types of lighting fixtures reduces over time. Grow lights are used from about 12 to 20 hours per day. Using an average of 15 hours per day the running hours per year will be 365 x 15 = 5,475 hours. Typically grow lights should be replaced after reducing to 80% of their original output. This means replacing Metal Halide bulbs after 6 months and High Pressure Sodium bulbs after 1 year. LEDs do not have to be replaced until around 4 years of use
Directional Bulbs
Incandescent and HID bulbs emit light in all directions and therefore light has to be reflected back towards the target plant canopy. All of the light will not be reflected back and will be lost in the form of heat.
LEDs emit light in one direction only and therefore not as much light must be reflected and therefore have an efficiency advantage.
Spectrum can be tuned
LED grow lights can use different white LEDs ranging from warm white to cool white, in effect adjusting the percentage of blue in the spectrum. Deep red, UVA and Far Red LEDs can also be added to change and ‘broaden’ the spectrum as needed by the grower.
Efficiency of the Light
There are two benefits to higher efficiency:
- Reduced electricity consumption – reduced running costs
- Reduced heat output
LEDs are much more efficient than any other lighting technology and allow growers to reduce running costs and heat levels in the grow area. The payback period for high efficiency LEDs is less than 2 years.
The reduced heat output of LEDs also allows growers to increase the light intensity in the grow areas for the same or less electrical footprint and maintain the room temperature.
Operating temperature
Both LEDs and LED drivers will last longer the cooler they run. To maximise the LED driver lifespan you can locate it in a cool area outside of the grow tent and hang it up so the airflow around it is optimised.
The LED bars or panels have heatsinks on the back of them. Ensure there is enough space above and around the heatsink to allow air to move freely and the heat to dissipate. If you are running extraction fans than you can direct airflow across the top of the LED grow light to increase air flow and minimise the LED temperature.
LED maintenance plays a crucial role
There are no moving parts on the latest generation of LED light fixtures but you can keep the heatsink and fixtures clean to maintain the efficiency of the heatsink and keep the operating temperatures down. A lot of LED lights do not have lenses or covers over the LEDs and they may attract first or moisture. However a lot of LEDs have either an acrylic or silicone coating. In this case you can clean the LED surface. Turn off the light and clean gently with a damp cloth. Do not use cleaning products as they may damage the LED surface.