ventilation question

[Rafghan]

so i got my 400w mh cool tube rite now with a 250 cfm fan pulling air off of it from the other side of the wall. should i have ducting on the other side of the cool tube leading out the grow room so it pulls fresh air across the light or should i let it pull the air out of the closet itself? if you look at the pic you can see what i mean.

 

[SensiStarFan]

so i got my 400w mh cool tube rite now with a 250 cfm fan pulling air off of it from the other side of the wall. should i have ducting on the other side of the cool tube leading out the grow room so it pulls fresh air across the light or should i let it pull the air out of the closet itself? if you look at the pic you can see what i mean.

My set-up,
Carbon filter pulling air from inside the grow room, inline fan hooked up next for the air pull, cool tube after the fan with air getting pushed through it, ducting on the other side of the cooltube running the hot air out of the grow area. In other words, pull air from the closet itself. Now if you have two inline fans and duct setups I would pull fresh colder air from outside the grow area and through the cooltube, then have the other fan and ducting pulling and filtering the air from the grow itself, but with only one fan the first option is best.

-SSF-

 

[Roddy]

OK, 2 questions here....are the plants hitting that fluoro light and is that cooltube as far away from the plants as it looks? You may want to even the canopy up a bit on the plants so all are getting good light, and side-lighting can cause stretch. Is there any way to even up the plant canopy, move the fluoro and the cooltube a bit? The cooltube can be around 10" or so from the light (maybe closer??), put your hand at the top of your plants and feel the heat coming off...if too hot for hand, will burn the plants!

With ventilation going through tube, I am betting it can be very close. The closer the light, the less stretch and more nodes your plant will have, giving it a tighter growth with many bud sites!

 

[pcduck]

should i have ducting on the other side of the cool tube leading out the grow room so it pulls fresh air across the light or should i let it pull the air out of the closet itself?

This depends on your grow room temps.

I have duct work/fans in place to do it both ways. Although I do like pulling fresh cold air from outside threw my a/c reflectors, seems to keep the room cooler. This also depends on what my outside air temp is.

 

[woodydude]

I would suggest not having the ducting drawing air from outside and across the light, this is wasting fresh air. By drawing air from inside the room, you are getting rid of co2 depleated warm air and sucking in fresh air.
My setup is as follows.
Carbon filter, ducted to cooltube 1, ducted to 715cMH fan, ducted to 2nd cooltube ducted to vented window.
This draws co2 depleted air inside my growroom through the carbon filter, also ridding it of smells.
This draws fresh air into the room, which also acts to cool the room and provide fresh air for the plants to breath.
Hope this helps.
Peace W

 

[The Hemp Goddess]

I would also say that it depends on your temps. I also have my ventilation set up both ways depending on temps. In the summer, I could not keep my space cool if I did not pull cool air from outside my closet to cool my lights.

 

[Rafghan]

OK, 2 questions here....are the plants hitting that fluoro light and is that cooltube as far away from the plants as it looks? You may want to even the canopy up a bit on the plants so all are getting good light, and side-lighting can cause stretch. Is there any way to even up the plant canopy, move the fluoro and the cooltube a bit? The cooltube can be around 10" or so from the light (maybe closer??), put your hand at the top of your plants and feel the heat coming off...if too hot for hand, will burn the plants!

With ventilation going through tube, I am betting it can be very close. The closer the light, the less stretch and more nodes your plant will have, giving it a tighter growth with many bud sites!

the picture is kinda hard to tell cuz its from a phone but yea i need to lower my cool tube forsure. the fluoro was kinda just set there after the fact, you think its okay to rest there or no?

 

[Rafghan]

I would also say that it depends on your temps. I also have my ventilation set up both ways depending on temps. In the summer, I could not keep my space cool if I did not pull cool air from outside my closet to cool my lights.

my temps kinda fluctuate durring the seasons as well but for the most part right now its around 78-80 a little warm for my preference, what do yo think?

 

[The Hemp Goddess]

No, I don't think that 78-80 is too warm.

 

[Rafghan]

fersure thanks. im thinkin for summer i will prolly do the same as you HG, as for winter its not too bad cuz it evens out with the rest of my place being cold as ice

 

[Roddy]

What kind of light is the fluoro? Is it a grow bulb? If not, it's not likely helping much.

If you can put some buckets or books, or boxes, or whatever you have under the shorter plants, you'll bring the canopy up even and the plants will thank you for it!

 

[Hushpuppy]

I agree on temp and ventilation. On a small grow, pulling in fresh air to the babies and then venting it through the light is good. 75 to 80 temps is good but watch yer humidity. If yer air in is very humid then yer room is going to be more humid as yer girls "sweat" under the light. Youngins seem to like a little higher RH around the 60-75% but the adults, I have found, like RH around 45-60%. I actually had to put a dehumidifier in my grow-lab to maintain my RH during the summer months, but mine is guite a bit bigger.

 

[Rafghan]

What kind of light is the fluoro? Is it a grow bulb? If not, it's not likely helping much.

If you can put some buckets or books, or boxes, or whatever you have under the shorter plants, you'll bring the canopy up even and the plants will thank you for it!

thanks,
im goin to use either pullys or chains to make the lamps height adjustable, and yea there both 40w plant and aquarium bulbs. also the the canopy looks super uneven cuz the plant in the back is older than the rest

 

[Rafghan]

i got the other ducting on this morning running outside the closet. when im home tonight hopefully i will be able to tell if it helped