Heat!

Hi all,
I have just upgraded from a pc case to a grow tent, it is 36"x20"x60" or 3'x1.75'x5'. I have a 600w cool tube in there running duct >box >cooltube> 250cfm blower> duct out of box into ceiling.
Also have a fan outside of the box with ducting sitting on it and routing inside box beside plants to provide them with cool air. My prob is I am hitting 34-36 degrees Celsius. I figured that a 600w would be to big for this space but how do i go about resolving this? My first thought would be a dimmable ballast. Maybe run it at 300w? Anyone have experience with this kind of prob? what was your fix? willing to be creative!

thejimi said:

Hi all,
I have just upgraded from a pc case to a grow tent, it is 36"x20"x60" or 3'x1.75'x5'. I have a 600w cool tube in there running duct >box >cooltube> 250cfm blower> duct out of box into ceiling.
Also have a fan outside of the box with ducting sitting on it and routing inside box beside plants to provide them with cool air. My prob is I am hitting 34-36 degrees Celsius. I figured that a 600w would be to big for this space but how do i go about resolving this? My first thought would be a dimmable ballast. Maybe run it at 300w? Anyone have experience with this kind of prob? what was your fix? willing to be creative!

Click to expand...

Edit" now running from inside box>duct>cooltube>fan>duct out of of box. Still 32 degrees celcius.
.

*PICS* or it didn't happen

Switch your lights to come on dureing the night an off at the day.

This should help a little bit , however to really solve the problem , id up my outake fan , and use the old outtake as an intake.

Good ventilation is the key to nice temps if you aint got ac, if you live somewhere cold like me a fan drawing coldair from outside is like free ac ^^.

kanx said:

Switch your lights to come on dureing the night an off at the day.

This should help a little bit , however to really solve the problem , id up my outake fan , and use the old outtake as an intake.

Good ventilation is the key to nice temps if you aint got ac, if you live somewhere cold like me a fan drawing coldair from outside is like free ac ^^.

Click to expand...

Yeah the intake bit I agree with, inline fan for exhaust and blower as intake, already running at night to, thanks guys.

I had/got kind a the same problem ..

tho Im not running a cool tube like you ... but my space is a bit bigger (3x7 feet and 8 in hight)

got a 600W HPS and I was running temps close to yours ..temp was like 29C in the room and maybe 32-34C at plant tops ..

cant afford a bigger ventilation untill next month .. and I need one .. have a 100mm and need atlest a 125mm or 150mm that can empty my room in a minut or so insted of 3-5 like now (schould empty my room in 3 minuts but filter do take some of the sug so Im guessing 5 minuts is more like it)

so the answer to me was two things ...

1.) switch to light on at night ..

I runn it from 17:30 (when Im home from work) and untill 5:30 in the morning (before I go to work)

made my Temps drop to 26C in the room and 28C at plant tops .. atlest fist 6 hrs .. then I guess my HPS have been warming it all up and next 3 hrs or so it stays like 28 in the room and like 30C at plants top ..

only last 3 hrs its about back to "normal" 29C in the room and maybe 32 at plant tops ..

but a lot better then 32-34C from the start and only climing ..


Ooh yea .. and it dont seems like ther is a big diffrent between temps nomather what distance I keep em from the light all the way up to 15 inchs ... so I guess my ventilation do work .. more or less .. also got a big table fan blowing at my HPS at a angle so it blows the air pass it and at the filter/ventilation in the sealing ..

I fist keepd the HPS like 25 inchs away then move it to 20" and now they grew up in the 18" and still able to keep it around the 30C at plants top ..


2.) I made a intake cannal leading to the out side to sug in fresh/cold air .. serves 2 purpose I guess ..




I know its a beauty right

well was just to see if I could make it work .. will buy some plastic tubing asap. and fit in ther insted of the cardbord ..

also considering a cheap bathroom fan to sug in more fresh air trough the tube .. as I did have to cut a extra hole in the end of my intake "box" near the floor .. as I got way to much negativ presure with just the out side air .. intake is the same as outtake .. with the extra hole its like 2x the size or the outtake .. and that seems to be right .. but it ony get half fresh air and half air from the room I guess ..

but its ok for now.. as it also made my temps stay lower for longer time and more fresh ..
and I dont need to open windows in the house so often anymore just to give em fresh air ..

sorry for the messy post/bad gramma .. a bit sleppy and stoned

So I sold the 600 annd got a 600w dimmable, running it on the 250w setting, still around 30 degrees, but better considering I only have an inline duct fan for both intake and exhaust. Going to pick up a proper exhaust fan like a squirrel cage or something of the sort in the morning, will get back to you on temps.