Advantages and disadvantages of water cooled LED grow lights

There exists a myth in LED technology that says that LEDs do not produce heat. This is not true, LEDs do emit heat, it is the law of physics that has not been beaten yet. The point is, LEDs emit much less heat than HID or incandescent bulbs. The best samples of modern LEDs can boast of optical efficiency of up to 60%, whereas the rest 40% is heat that needs to be taken away from the LED chip and dissipated. There are several methods of LED grow lights cooling like free air convection, forced air convection, water cooling. Let us look in more details at water cooled LED grow lights to see if it is a suitable solution for your project.

Advantages of water cooled LED grow lights:

Water cooled LED grow light designs are very slim, as they do not require heavy large size heat sinks. This can be converted into direct savings for delivery charges to the place of installation. Slim size allows more growing space and more freedom for people servicing the plants in constrained conditions of vertical farms. In the case of traditional greenhouses, water cooled LED grow lights will have very small shadow footprint allowing more sunlight penetrate the greenhouse, so more natural sunlight is available for the plants.
Water efficiently transfers heat from LEDs to the place where it can be cooled or re-used for heating. This way it is much easier to control temperature on the plant leaves, which is a crucial parameter for successful growing.
HVAC systems with less power are needed for indoor growers, as heat is transferred from the growing area to the area where it can be cooled or recycled. This is a direct saving on CapEx and OpEx, as the higher power HVAC systems cost more money and consume more energy. It’s a great advantage to growers who have power limits, or who plant to expand their greenhouses but do not want to invest more money into new power generators or transformers.
In greenhouses you need water for delivering nutrition to plants and have to do all the plumbing anyway, so water cooling is the preferred method of LED grow lights cooling as you still have to have all the infrastructure like pumps, plumbing etc.
Water keeps LED junction temperature below 50 degrees C, which improves LEDs lifetime and light output.

But like in any technology, water cooling for LED grow lights has its drawbacks, and let’s look at them, too.

System complexity and cost. Compared to free or forced air convection, water cooling is more complicated and requires some plumbing work and chillers to cool down the heated water after the LED light sources.
Water accelerates corrosion of metal parts. A poorly designed water cooling system will damage the light after a few years. Dissolved chemicals in the water will deposit on the sides of the water channel and reduce cooling capacity. So distilled water should be used to reduce the risk of system degradation and damage.
Water is a favorable medium for biological growth, which may also deposit on the LED grow light water channels and tubes and impair heat dissipation. Chemicals need to be added to water to fight undesirable flora and improve longevity of the light.
Bubbles may appear in a water-cooled system that is designed and constructed incorrectly, and these bubbles may stay in the same spot of the LED grow light for long time, thus reducing heat dissipation.
A cost of mistake or pump failure is very high. If an unskilled operator will switch on the system without water circulation, it may lead to fatal damage of expensive LED lights. It may happen if the pump fails.
In a poorly designed and constructed water cooling system leaks may lead to LED grow light damage, short circuit and even risk of electrical shock.

Therefore, along with its immense advantages, there are big risks and disadvantages in water cooled LED grow lights. There is apparently no one-fit-all solution for horticulture LED lighting.

Read more about water cooled LED Grow Lights.

For more information:
Genesis Scientific
[email protected]
www.gs-horti.com