How to calculate how many LED Watts is how many Lumens?

[WilliamB217]

Hello!

So I've searched some threads, by keywords and not, and I didn't find an answer for my question. So perhaps there might be answer laying, somewhere... But I though this would be quicker. So I have also searched within google, and didn't find anything usefull. When looking for led lights, I usually find only how many watts they have, not their power. And the charts usually only cover like 5-10W. While in the shops, they don't put how many lumens the lamps have.

Also, do I need anything else for that kind of lamp? I read some topics here, and some of you say I would need better cooling. I have a 40x40x120 tent, and a 100m3/h fi 100mm fan in the ventilation tunnel. So firstly, what would be appropriate LED lamp for such tent, and will it be enough if I buy 13W clip fan? So it mixes the air and kind of cools the lamp.

 

[Hook Daddy]

Watts is a measure of power consumed, so there is no formula to convert power to lumens. You need to know the efficiency of the light first. LED lights are typically measured in PPF when advertised instead of lumens, I think that is what you are looking for.

 

[coreywebster]

Lumens are for humans.

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A basic description.



You want 50w for a 40cm x 40cm space, assuming we are dealing with a reasonable white based LED light.
Probably not many lights on the market less than 100w, so it wants to be dimmable.

Yes you want a small fan to circulate air, a pc fan will work in such a tiny space also.

 

[WilliamB217]

Watts is a measure of power consumed, so there is no formula to convert power to lumens. You need to know the efficiency of the light first. LED lights are typically measured in PPF when advertised instead of lumens, I think that is what you are looking for.

thx！