400w HPS heat problem.

[ntb_0]

hello. i am trying to have my first grow and i have an issue with the temperature. it gets up to 37 - 40*C in a 50x100x150 tent. i am using a 400w HPS Sunmaster dual-spectrum + cool tube 5" and an advanced star eco duct 5" 210m3/h inline fan sucking the air trough the cool tube. i also have two fans in the tent for the ventilation and i made a hole for passive intake at the oposite corner of the extraction fan. i added a picture made in paint of my tent. it is actually a greenhouse and i added mylar inside and some duct tape all over outside. i apreciate any help. thank you

 

[ntb_0]

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[corky1968]

I'm not totally sure, but I think a 400 watt HPS light sounds overkill for such a small cabinet.

Hence it's very warm inside. If the ambient temperature wasn't so high then all would be better.

Other than get a smaller light or increase the air intake there isn't many options.

 

[DoubleTripleOG]

Your at about 100w psf. That's double what most reccomend. Can you make the cab a little bigger?

 

[ntb_0]

well, it is a improvisation .. a greenhouse transformed into a tent but now i am consider buying a real grow tent. 0.8x 0.8x 160 would be ok ? i will only have 2 autos now as my first grow ever and in the future i am not planing to have more than 4 at the same time. do i have to replace the exhaust fan i have? or to add one more ?

 

[corky1968]

That larger tent would be fine. Just keep the same fan and everything else.
Just replace the tent and save it for starting small vegetative plants with
CFL or LED lighting if you want.

 

[ntb_0]

That larger tent would be fine. Just keep the same fan and everything else.
Just replace the tent and save it for starting small vegetative plants with
CFL or LED lighting if you want.

i hope you are right .. i forgot to mention, my exhaust fan is at 100% and i get 37-40*C (my room ambient is 24*C) and i do not have a carbon filter yet. i know the exhaust doesn t work so well with the carbon filter on (20-25% less power). if i buy a carbon filter + exhaust and i keep the curent exhaust fan outside the tent then duct>cooltube>duct>outside then another exhaust + carbon filter pushing the air straight out.

[/IMG]
would that be the best option ? i want to do it right from begging to get the best results, and i won t get a CFL or LED. i think i can start straight away with HPS, at the beggining i will keep the light as far as i can then i will bring it closer easily

 

[corky1968]

A separate fan for the carbon filter would be best.

 

[Granger2]

400w in the new tent you described would be about right, at 57w/sq ft. For temp control, you'll need 2 complete air exchanges per minute. Good luck. -granger

 

[useless.gardens]

That larger tent would be fine. Just keep the same fan and everything else.
Just replace the tent and save it for starting small vegetative plants with
CFL or LED lighting if you want.

agreed. smart idea.

 

[Mr. Miyagi]

It may not seem like much, but having your incoming air lower will also help...(as we all know heat rises) so it's kinda redundant to to cool a room with warm air... just my 2cents...

 

[sadpanda]

and have your lights-on cycle at night to take advantage of cooler temps, eg 7pm-7am for 12/12 lights on