lens hood cooling question

[ross]

I am planning on getting a lens hood for my next grow, and am looking at fans to cool the 600W that will be in it. i was wondering what a good CFM rating i should be looking for. i want to be able to put the light very close to the plants to combat inverse square law, like perhaps a foot away, so i was looking at a fairly high cfm, 268, is this too much or is this what is necessary to be able to put your light very close to the plants?

 

[Vegs]

I use a 265 CFM squirrel cage fan. Although it is a little overkill, it still gets the job done very well. It could be a tad less noisey... I'm sure you could go 100 CFM lower if need be.

 

[ross]

how close can you keep your light? you use a 400W, right?

 

[The Hemp Goddess]

I use a 1000W HPS. With the glass in place, I can get the plant canopy within 5-6" from the glass without burning the girls.

 

[Herm]

Hello THG,

When did you start to move your light down toward the canopy of your plants? right now I am running it about 20 inches away but my plants are still seedlings. I am also running a 1k watt HPS with a hortilux super blue if that makes any differance and so far my room has not gone above 80 degrees.

 

[ross]

I use a 1000W HPS. With the glass in place, I can get the plant canopy within 5-6" from the glass without burning the girls.

wow, how many cfms does your fan pull? how close would you expect to be able to get it if you used a 600W?

 

[NorCalHal]

I also use aircooled 1000w lights and use a Can Fan 6" rated 440cfm to cool them off. I can get my light the same, 6-8" from the canopy.

Remember to allways PULL air thru the light, not push.

 

[ross]

I also use aircooled 1000w lights and use a Can Fan 6" rated 440cfm to cool them off. I can get my light the same, 6-8" from the canopy.

Remember to allways PULL air thru the light, not push.

i guess 270 CFM isnt overkill then

 

[Vegs]

I have a 1/4 inch thick non UV rated glass and keep it about 6-8 inches away. Check out my journal for pics to see the 90 degree mounting and setup.