Many growers think that white paint is the best reflective lining for grow room walls. We have tested a lot of grow lights in a lot of different environments to see what works best. We can tell you definitively that matt white paint is as effective as the standard reflective lining in grow tents but no better.
For once the best solution is actually a very easy and cheap solution - standard silver mylar from your grow shop.
The reason: It's a good reflective surface and it's directional. Directional means that the light comes from the grow light at the top of the grow tent, reflects off the grow room wall and is directed onto the bottom of the tent. The diagrams below show the test of a matt white surface and a silver mylar surface.
The test is a simulation of the grow light at the top of the tent and the plant canopy at the bottom. When the light is spread wide it must reflect off the grow area walls and be directed onto the grow. Let's see what surface type does this job most effectively.
Matt White result
When the light hits the matt white surface it is diffused i.e. it is sent in every direction. A lot of the light is reflected back up to the top of the tent where it is wasted.
Reflective materials test for matt white paint as a grow room liningSilver Mylar result
When the light is reflected off the silver mylar surface it is reflected down onto the plant canopy. This means most of the light hitting the side walls is directed towards the grow area.
Reflective materials test for silver mylar as a grow room lining
Comments
Tom
I watched the video of live par tests with all the different materials, mylar won out. While Universities may be developing special paints, mylar is the best reflector we currently have.
June 13, 2023
Matt
You happen to be the very first article I have read saying mylar is more reflective. That may be the case with hid lighting but with led that is not the case. Not to mention white dissipates heat better than mylar. A study recently done through Purdue university was able to create a almost 100% reflecting white paint that hit the Guinness book of records. I think most will disagree with mylar being more reflective with the new age of grow lights.
September 27, 2022
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