Attic Growbox complete

[nvus420]

Whats up fellow stoners! Hope everyone is doing great! I am super stoked right now b/c I have completed my room build and setup! I built a 5x5xangled7' box in my attic. I framed out the box using the existing trusses so the box is angled to about 12" wide at the very top! I framed the entire box using 2x4 and 5/16 board as my outer walls! I then insulated the inside with r60 and finished the insides with sheetrock. I then added panda film on the walls. I will be growing 6 plants in soil with an automated drip system for watering! I will be using an air-cooled 400 watt HPS with a 6" inline fan and 6" filter attached so the setup will go filter-duct-aircooled hood-duct-fan-duct to outside grow box up to ridged vent. I will be using a active exhaust/passive intake ventilation setup. I have ran 2 6" ducts to my main hvac supply in the attic and tapped in. So I will have 1 6" passive intake at the bottom of the grow room on both sides of the grow box, so I will have a total of 12" of passive intakes which gives me a 2:1 ratio for intake to exhaust. I will be growing greenhouse seed white widow feminized for my 1st round. I will run my exhaust system 24/7 so I can draw in plenty of c02 and prevent backdraft of the odor into my home hvac system! If anyone has any questions/thoughts/or comments feel free to speak. We all learn from each other. I will post more later, kind of in a hurry at the moment

 

[Roddy]

Attics get hot, lights will really make it hot, do you have plans for cooling? Edit to add, not sure, is the hvac heating/cooling??

Also, Greenhouse seeds...I've not had much success with them. Good luck, I'll be watching to see how this goes!

 

[Hushpuppy]

That sounds like a nice setup. You say you are running your passive air intakes to your HVAC which sits in the attic? That should work nicely as you don't want to pull hot stale air from within the attic space into the grow space.

No that you have completed that you need to go ahead and build a second one that you will need for vegging and cloning so that everything isn't being done only in the one space

 

[Budders Keeper]

Howdy. I have a 5x5 space also but mine is ground level, concrete floor. Just a heads up, my 6in elicent inline fan is just slightly over 300CFM. I had it pulling through filter and a/c light. It wasn't enough to cool light and room, temps were 85-95. I had to add a 4in vortex to cool light, with the 6in pulling from top of grow space.

I'm concerned being in an attic you may need a little more cooling power. I don't know the temps where you are so this may not be an issue.

Good luck with your grow. Mojo for the dankity.

 

[nvus420]

Whats up guys! Thanks for the replys and concerns! I will be cooling/heating the grow box through my passive intakes via the home hvac system. I have a extra 6" inline fan incase temps get too high, if they do I will just add the extra fan to the light only and use the other for the filter/exhaust! I will cross that bridge when I get there...I really think that pulling air in from my hvac system will really help with cooling and heating. I have used greenhouse seeds in the past with much success, only brand I have ever used actually. I will post some pics soon! Time for a rip session

 

[LEFTHAND]

sounds like a nice lil set up there...
you say your room is 5x5 so 25 sqft... and your using a 400w to light it..
i would say/think you will need to get a bigger light or atleast another one..
LH

 

[bubba902]

I'm with LEFTHAND on this one, Sounds like a very very nice setup BUT it will be WAY under lit.
I use (2) 400w HPS in my flower room which is 5x5, and I'm still a bit under lit.

Rule of thumb is ATLEAST 5k Lumens per sq ft. MAX a 400w HPS will throw out is 50-55K Lumens.

1 400w is enough for a 3x3 MAYBE a tad more..
Once you get the light situation figured out, This will be one heck of a producer..

Props for the GH WW.. Good luck! Be safe!

 

[getnasty]

I'm with LEFTHAND on this one, Sounds like a very very nice setup BUT it will be WAY under lit.
I use (2) 400w HPS in my flower room which is 5x5, and I'm still a bit under lit.

Rule of thumb is ATLEAST 5k Lumens per sq ft. MAX a 400w HPS will throw out is 50-55K Lumens.

1 400w is enough for a 3x3 MAYBE a tad more..
Once you get the light situation figured out, This will be one heck of a producer..

Props for the GH WW.. Good luck! Be safe!

A 400W puts out 50K Lumens. Sun Agro's put out about 53k. A 4x2.5 growspace is 10 sq ft. 50000/10=5000 Lumens per square foot. The maximum for a 1x 400W light. Double that up, using the dimensions of his room, and he is underlit by 6000 lumens.


Changing one of your 400s to a 600 will solve your problem. If your ventilation is adequate, I'd go with 2x 600s.


-nasty

 

[nvus420]

Whats up guys.......I actually do have another 400 watt lumatek electronic ballast along with another air cooled hood but truthfully I do not have room for it.....my room is not a square 5x5.....it is actually 4' x 6', but the 6' side has about a 60 degree angle and the 4' side has a 75 degree angle.....so it is not completely square...I will add a strip of panda film on the 6' side and let it hang to act as a wall, so im not ligting area that is not being used due to the taper of the wall. I really appreciate all the input.

 

[LEFTHAND]

hey man
i see your problem lol.. you could always mount the hoods on either side on a slight angle... even with 2 400w and at 24 sqft your still a bit under lit..
at 100 000 lumems at 50 000 a bulb your looking at 4166 lumens per sqft. under lit by 830 lumens.. and at 55 000 lumens per bulb your looking at 4583 lumens per sqft and under lit by 417 lumens..
its not much but every lil bit matters when it comes to lighting your crop..
i would try and mount em.. personaly i would go 2 600w.. but a 600w and 400w would be almost 6000 lumens per sqft...
jmo..
LH

 

[nvus420]

What's up guys!? I ran a few heat test with the 400 hps witter on the "super lumens" setting on my lumatek balast........and u guys were right! Outside temps were 85 and my grow room temps were reaching 100! I only had the 6" passive intake that's a tap off of my main hvac & the 6" centrifugal fan inline with a filter and air-cooled hood! With this setup I was not getting a draw from outside the room! The incoming air from the hvac was actually blowing harder than my exhaust fan was sucking bc the crack at the outside of the door would blow a lighter out! I added an additional 6" centrifugal fan inline with the exhaust system so now my exhaust is as follows : filter-air-cooled switchable 400 watt mh/hps-6"fan-4' ducting-6" fan- 3' ducting! This creates a strong negative pressure in my grow room! My room temps r down to 82 max! I have another 6" passive intake tapped to my hvac that I will introduce to keep temps in the low 80 range if needed! It is closed off now with an adjustable buffer! So u guys were right.....my solo 6" fan would not cool the room enough! I'm starting the seeds on Monday! I will start my journal on Monday in the journal section! Later guys

 

[The Hemp Goddess]

Tell us more about your fans. They don't sound like they are doing the job they should be doing. It shouldn't take 2 6" centrifuge fans to cool your space. Remember you still need about another 600W of light in that space to be adequately lit. Maybe you should consider some passive inlets, too. Also, I recommend not using a filter until you need to. It puts and extra load on your fan, so don't use it when you have no smell. I also recommend speed controllers for your fans.

 

[Dan K. Liberty]

I would like more details too . . . making decisions on this aspect of my setup . . .

 

[nvus420]

OK guys, here is the scope on my fans ( active exhaust/passive intake system )......if you want more just ask. I started a grow log that will also explain and you can follow my grow if you want!

I have 2, 6" passive intakes into my grow room that are tapped into my main hvac system....just like "another room" added onto my house......These 2 passive intakes also act as active intakes when my home hvac system is blowing/ON and this is why I have to use 2, 6" fans inline with each other on my exhaust system.....I want complete suction into my exhaust system at all times and 1 fan does not do this when my home hvac is ON/blowing. My 2 exhaust fans are also connected to variable controllers so they do not run wide open. Both are set to medium! Also 1 intake is closed until the outside heat tells me to open the other (#2) intake! My grow room temp stays the same, maybe a lil lower, than my home b/c I am tapped into the hvac system and my grow room is insulated so well!

If you need more explanation.....just let me know....Also PLEASE follow my grow log for a 5 Greenhouse Seed Co. White Widow, 1 Th Seeds MKage, & 1 Paradise Seeds Delahaze grow in the GROW LOGS forum! All are fminized seeds

 

[The Silver Bullet Special]

SO do you have two 6in fans that are piggy backed into the same exhaust line? IMO wouldnt that just move the same amount of air as your fastest fan but just with less strain on your first fan.

I would run two seperate exhausts and merge them together past the fans for one final exhaust pipe outside. I contemplated an attic grow but after a week or so being on the forum talking to people here I'm just going to use te spare bedroom and pump the air up into the attic and out the dryer vent once it has been filtered. (maybe you have addressed this in your other thread I will check out in a little while I'm curious about an attic grow but its too hot where I'm at even with an HVAC tapped)