Airflow needed for LED Box

[stinktier]

Hello,
with HPS lamps, I red that the airflow needed for a growbox with carbon filter in cubicmetres/h should be about the same as the power consumption of the lamp. But how is it with LED panels? Obviously they need less but how much?
Specifically: a 60x60x140cm Growbox with a Mars reflector light (100W).

On that note, is it okay to use a carbon filter at half its capacity? Do they still do their job then? The samllest filters I saw (Can Lite) take 150m³/h...

 

[415friendly]

How are the temperatures in your box? If that is not an issue I've read that getting a fan to match the CFM of your carbon filter is best to make most efficient use of your filter

 

[stinktier]

Temps are average, 20-25 and summer max maybe 30°C (68-77, max 85°F). LEDs do a got job at not wasting energy for heat! If someone says "don't run filters at half capacity, they will not do their job then" then I will do what you say. Otherwise I would like to save money, electricity and noise by choosing appropiate ventilation.

 

[415friendly]

From what I understand, you don't want to have an exhaust fan that has a CFM a lot higher than the CFM rating of your filter, because then the fan pulls air through the filter too fast and doesn't allow the filter to be fully effective.

If you're having no heat issues you can get a lower rated fan and thus a lower rated filter.

Personally, I would always look at a 6" fan and filter for versatility. Everyone seems to expand their operation further down the road, and there's only so far that a 4" fan will take you.

 

[stinktier]

Going over the recommended CFM isn't the issue, it's going underneath.
A 6" opening is existent and I intend to use that since I want it to be silent. Bigger diameter -> less fanspeed for a certain amount of air

Too bad no LED users chip in with their knowledge, but thanks for your answer!

 

[Graytail]

I've used both hps and LED and I would estimate the heat reduction, very roughly, at ~20%.

I can run 1000 watts (draw) of LED in my 4x4.5x7 foot (120x130x200?) space, with only a low-flow 4 inch exhaust (about 50 cfm).

The most important factor though, is your intake temp. I can keep mine between 70-75F. With that ambient temp I get an 85F high when the lights are on. If you can't keep the intake temp down, you'll have to vent a lot more air. The 100 watts of LED in that space should be easily managed.



It's hard to give specific advice on matching fans and filters and cubic space. But yes, a bigger capacity fan is better, keeping in mind that you want to try not to run it lower than 70% of full power - it's hard on the motor windings to run it too low. So don't go huge.


[Edit] I did a little math - my space is about 6 times your cubic space? If I can vent 1000 watts, you should be able to vent 160?

 

[stinktier]

Thank you very much! Those numbers help a lot.
Kind of what I expected. It's hard to find fitting equitement in this range. Maybe a high quality bathroom fan would be good. Without a big casing, that fits inside the pipe.