Uh oh, will this light even fit?

[ScrubNinja]

Hi all, I'm taking my first steps into HPS growing and building a wooden box at the moment to do it in. The box will be 700mm wide, 1200mm long, and 1300mm high. That's about 2.25ft x 4ft x 4.25ft. And I'll be running a 600w cooltube horizontally.

Now the exact inside width is exactly 700mm (so this box can fit through doors). I bought the smallest cooltube at the store which is 500mm long, and has 150mm ducting. I want to have a passive intake in the bottom of the cab, and the air flowing in from there, to the open end of the cooltube, then out of the cooltube through a sharp bend in the duct, and then through a carbon filter and out of the cab.

Problem is, with the cooltube and ducting taking up 650mm, I'm only left 50mm or 2 inches between the cooltube opening and the wall of the cab. Will this be enough? I can't find any CFM details for my ezi-air 150mm inline fan but I'm assuming it's a little lower spec than most as it was the cheapest in store, but recommended as the quietest. I've also purchased a fan speed controller as I hope to push the bare minimum of air needed through it, for stealth reasons.

So will that 2 inch gap work? Thanks for any help or alternative solutions. The wood has been cut but not assembled and the light/fan etc are here so I'd like to work with them if possible. Would it be a bad idea to just spin the cooltube around 90 degrees so it's running along the length, instead of the width? I'll be scroggin' so i need good light coverage.

 

[FreezerBoy]

600 watts is a lot in that box. Especially with such a small fan, bent ducting and limited intake. I think, at least, you'll need a bigger fan.

How are your stealth issues? Can there be visible vents? If you want the lamp perpendicular to the length, I'd give it a dedicated run and vent/scrub the cab separately like the drawing at left (ignore the right, this was for another thread originally)


If you have to hang parallel to the length, the 600 needs some space between lamp and canopy anyway. That space could enlarge the footprint enough to hit the ends. You can curve the screen up at the ends, too.

 

[ScrubNinja]

Ah bollocks, thanks for the insight FB. It makes sense because I decided on a 600 back when the box design was nearly double the floorspace. Hmmph. I could swap it for a 400 but eff that. I'll buy more wood and make the box the original dimensions (1200 x 1200 x 1300) and I guess I'll have to dismantle the whole unit when I move house.

For the record, I was aiming for extreme stealth but maybe I'm dreaming. The box is just gonna sit right there in my living room, kind of at the dark, unused end. If anyone asks what it is or why there's a power lead, it's a humidity/temperature controlled environment for delicate computer parts and music equipment etc. I'm a bit of a nerd, and this is a really mouldy environment, so I can pull it off, but I would prefer for them not to be suspicious in the first place.

All the air ins and outs will be at floor level. I'll have the box raised off the ground using some planks to sort of build ducting underneath. Here's a jpg I whipped up earlier. Obviously the exhaust hole will have the ducting attatched to it from the top. You can see the exhaust partition is seperate from the in-flow.



So if I adapt all that to the new, 1200mm square floorspace plan, and use the insulated ducting I just ordered, and the 600, do you think this might work and be semi stealthy?

Oh one last thing, I did want to contain the ballast inside the box somewhere, isolated from the grow. I was thinking of utilizing the exhaust air after it's cooled the cab and the bulb, and have that flowing over the ballast somewhere late in the chain. Does that work or is the air too hot?

Thanks a million!

 

[spaceghost22]

600 watts is a lot in that box. Especially with such a small fan, bent ducting and limited intake. I think, at least, you'll need a bigger fan.

How are your stealth issues? Can there be visible vents? If you want the lamp perpendicular to the length, I'd give it a dedicated run and vent/scrub the cab separately like the drawing at left (ignore the right, this was for another thread originally)


If you have to hang parallel to the length, the 600 needs some space between lamp and canopy anyway. That space could enlarge the footprint enough to hit the ends. You can curve the screen up at the ends, too.

I love your drawings freezerboy!

Very nice!

 

[FreezerBoy]

If you're willing to go back to the drawing board, and you seem a DIY kinda' guy - Have you considered building a custom cooltube? This particular Hurricane Glass is just under 360mm. Lots of folks here use them and tutorials abound.

If you leave the ballast in the cab, that's even more heat to remove, and I think you're underpowered already. Play with this fan-intake calculator and see what that tells you. While your blue rectangular intake appears (more than) double your red exhaust, the blue rectangle is not your intake at all. Your real intake is the break in the green outline which looks suspiciously similar in size to your exhaust. Even if you lift the cab a full 150mm, that opening needs to be much wider.

 

[FreezerBoy]

Aw crap! Spaceghost has hyperlinks! We're doomed. What idiot rat bastard taught him to do tha ... say wha? ... D'oh! ... never mind ...

 

[ScrubNinja]

Hey thanks for the suggestions. Man, I am kinda up shit creek here without knowing the CFM of the fan, I guess. I think I will go with the larger box idea and the equipment I have, and upgrade the fan or redesign later if needed. I dunno, just got a feeling I can do this.

With the ballast, I actually meant having it isolated/insulated from the grow area, but still inside the box. Imagine if I built a small chamber on top of the exhaust hole in the floor, and had the ballast inside that, and the ducting from the cooltube would attatch to the top of that chamber. (don't make me get that MS Paint out).

Totally agree on the intake sizes. I should point out it wasn't drawn to scale, but very good point and I'm determined to break away from the airflow problems I'm stuck with in my PC cases. Thanks again.

 

[FreezerBoy]

D'oh! One of these days, I need to learn how to read.

I really thought I saw a "150 CFM" in your post but, nooooooo! All you said was 150mm. My catalog lists 5 different 150mm inlines. The lowest rating is 243CFM, the highest is 449CFM. You're moving 2-3 times the air I thought you were when responding earlier.

 

[ScrubNinja]

O rly?! Well that is some good news then, cheers. I worked out I need to shift about 115cfm for 3 room changes a minute so to hell with the consequences, I will just put this lot together as is, only with the cooltube running lengthwise. Looking at the cab sizes of some other 600w grows, I think it'll be overkill for sure in the light department but no big deal to downgrade later. I am just dying to get this show on the road and it's been a bumpy costly road so far! Can't thank you enough mate, have an excellent day!

edit: still wondering about the ballast cooling situation if anyone is in the know

 

[ScrubNinja]

Well I answered my own question by sticking a thermometer in the exhaust stream. I think it'd be a bad idea but I know at least one guy has done it on here.

Freeze, I emailed the manufacturers and it's um, I forget exactly, 97 litres/sec or thereabouts, which I believe would be the 243cfm.

Anyway, I'm feeling really good about this - things are starting to come together rapidly. Main changes have been:

• a true realisation that 600 watts was never going to work in here, ever
• scrapped the underfloor intake maze idea and now it'll be on wheels and light blocking is all taken care of inside the cab
• I'm thinking of scrapping the cooltube idea altogether and going with a hood - right at this very moment I'm thinking two of these 150 watt hps hoods.

Due to the stealth nature of my intakes and exhausts (no external ducting possible) the hot air tends to cycle back through a little but considering I've only put 2 x 90mm intakes so far and it's not raised on wheels yet, I am doing okay temp wise with 200 to 300 watts of CFLs hitting a max of 31c if I have lights off during the heat of the day (18/6 currently). It's summer in the tropics here so that's actually cooler than the outdoor girls are getting.

Anyways, my big question for this post is: Do you think those 2 x 150w hoods (with the glass added) are a good plan for me? I ultimately want a 4 plant DWC scrog when the sawdust settles. Otherwise I was thinking one larger air cooled hood with a single electronic/digi 250 watt hps. I like the idea of two light sources instead of one, especially for a scrog. I think a 400 may be too hot to handle.

Heres some pictures to help things along.









These guys have had such a hard time with the heat, plus I'm usually a coco guy. These are in some crazy weird shit called "potting mix" so please cut me some slack, it's a bumpy road

Sorry for typing up a novel but I'M EXCITED! Should I go the dual 150's?

Oh also, haha anyone know if you can run two of these fans on the one fan speed controller?

 

[FreezerBoy]

right at this very moment I'm thinking two of these 150 watt hps hoods.

My concern are the built-in ballasts which add heat to the cab. But, if the cab is self enclosed, whatever ballasts you'll have are inside anyway. With a 150, I had the ballast inside. Upgrading to a 250 forced me to cut a second intake (which I really should've had all along) and remote the ballast underneath my freezer.

 

[ScrubNinja]

Word, that had me a little antsy at first too, FB. But then I applied ye olde stoner logic and figured since it can run 300 watts of CFLs with attached ballasts, that it could handle 300 of hps with ballasts. I'm not sure if that's an accurate way to work it out, lol. But its all I got. I'm sure I've seen guys arguing on here about cfl vs hps heat output per watt, so they must be sorta similar, so I can't be too far wrong...surely?

I'm gonna keep looking at hood options anyway and try for something air cooled. Australian hydro stores do not give ya much choice sometimes.

And if all that fails I have 900mm x 900mm of that German dimpled sheeting they use for reflectors. And tape. Lotsa tape.

 

[DiscoBiscuit]

Ninja, is that AA birch plywood? You went for the good stuff!

 

[JACKtheREFFER]

that is a killer box there ninja >>>> i love boxes for growing in check mine out !!!! the link is in my signiture
well keep it up buddy im pulling up a chair to watch your progress

 

[B420]

Don't stop trying yet you can definitely fit a 600W in there. I currently have a 600W in a very small area. Check out the grow in my sig I have a 600W in under 10sqft. I used to go by the name basement420 that is why it is on a different name.

 

[ScrubNinja]

Ninja, is that AA birch plywood? You went for the good stuff!

Hi DB! Yeah mate it's "15mm hardwood exterior ply" and I couldn't be more happy with it in terms of noise reduction. It stops more noise than I was ever hoping it could. It cost a LOT but this is an investment after all

Thanks Jack! I will check it out right now, my man. I was thinking of starting up a proper grow thread for this box once it's finalised but thank you for stopping by this one!

Edit: missed you there B420. Yeah I am hanging onto the 600 for sure! I'm not gonna rule out a winter grow in there. Could be doable indeed and I'm moving house soon so I can always hook up external exhaust ducting. Cheers.