Couple questions about my cab design (diagram included)

[cobain420]

Hey guys I've attached a picture of my potential 250W HPS cabinet.

Here are my main concerns:

On the diagram I drew up in Paint, I think I have a pretty decent grasp on the design of the cabinet, and how it will go together.

Here are my problems:

1) Light Escaping. On the diagram I've circled two areas and labeled them "PROBLEMS" I need to come up with a way to have the 4" ducting enter and exit the cabinet, without allowing any light to escape the box. In addition, nothing can be mounted on the exterior of the box, everything has to be contained inside.

2) What CFM and type of blower. I need some something as quiet as possible, that will allow ample cooling for a 250W HPS in the pictured setup. What would you guys recommend?

3) Holes in cabinet. Where the intake and exhaust exit and enter the cabinet how can I hide this as much as possible? I am planning to have both the intake and exhaust located on the back of the cabinet, to make less noticeable. I'll throw some mesh over the holes to avoid any bugs getting in there.

4. Odor control. Is there any small way to minimize the odor leaving the cabinet? What would be the smalled carbon scrubber I could assemble? Would I have room to fit it? No one else should be around my box but myself, just in case odor control always helps with peace of mind.

Ok that's it guys, all the problems which have struck me. Problems I need to get solved before construction starts. Please help me, these are the things holding me back! THANKS!

 

[george j warner]

1) light escaping : see drawing


this is your plan to the individual measurements ... the intake fans have moved if you want a carbon filter to remove the smell here it is

also the main fan can be used as the air flow fan aswell

see pic following shortly

 

[george j warner]

here you go modifercations included .... for the intake vents either have 2 x 4" holes or 1 x 5" cover them in mosquitto netting ... and if you can afford it buy a back draft shutter ..(will stop cold air entering your grow room when the light/fan is off)

then just add a digital thermometer at the top of your plants and your rolling





laterz

 

[cobain420]

Wow man thanks a ton, that setup is killer, and exactly what I was looking for.

I am definitely just going to use one single rubber maid tub, filled with soil mix. I have used this method before under 2K HPS, with 8 plants per tub and had great results. Also cuts back on watering time. In addition, the soil mix I use requires plain tab water only, so every 2-3 days I just soak the soil mix until water comes out of the drainage holes. Nice and simple.

Do you use a similar system to the one which you drew up? If so, how are temps in the cabinet using a 250W? Would a 400W be possible?

Just to clarify, the fact that the exhaust (hot air) is surrounding the intake isn't going to make much of a difference? Just trying to think after 12 hours of running, there will be a ton of heat built up in that chamber, want to make sure this setup is going to work properly. Looks great though.

BTW: This setup is obviously the flowering stage, which requires the most room. I will probably veg in the same cabinet for now, until it's time to flip the lights to 12/12. When that time comes around I'll add an additional small veg cabinet, to maintain clones and bring up seedlings.

Any idea of what people yield with cabinets? When I ran 2K HPS, I yielded about .7G/W - I know this is no where near the 1G/W everyone strives for, but it kept me plenty happy.

I noticed 5" RVK near the picture of a blower, what does this stand for?

Also, would it be better to push air past the bulb? Would this be possible?

What program did you use for that setup?

Thanks again bro, pictures will be on the way when construction begins.

 

[george j warner]

the intake vent is a back drafted 5" hole the outtake is throught the carbon filter past the fan and through the light and up the vent ... i used this method before slightly smaller construction 3ft wide not 4ft... as long as you keep the fan above 50% running the heat doesnt build up ..... temps with a 250watt HPS in the middle of summer was around 80 degrees ... coz obviously the chambers cold air coming in is as cold as the air outside !!!!! in winter it was around 73 degrees so dial down the fan speed controller to 40% and the chamber hits 75 degrees ... perfect


the noise level with the fan isnt that bad with the speed controller ... if you want to remove all noise either buy an acoustic fan ...or wrap the fan in large (probally 12") acoustic ducting... but the spped controller cut out the main noise .

i would say a 400watt is possible but if i were you get a 250watt digital ballst instead .. a lumatek blue or purple (purples better) then you got 300 watt light lumens while only using 200watts of power ..

or go 400watt digital with 500watt light lumens while using 300 watts up to you .. maybe a 400 would be better with the extra foot ...

yes the design was on a flowering stage ... but just disconnect the air cooled light and have the duct from the fan go straight out the top ... then just hand a T5 or something (mother wing) is best

now yeild .... i have packed in 12 plants in a area 3ft W x 2ft D and 5ft H and yeilded half a kilo with a oxy drip system (diy own design)under a 250watt and magnetic ballast ! the strain btw was white widow crossed with super silver haze ... and they were 3ft tall at harvest ... so yeilds 1gpwm isnt hard you just got to use the space in the way where you got loads of plants without comparmising root space ...... then a 250 is loads ... and that wasnt even air cooled !

RVK is just the type of grow fan (normal grow fan ie like a vortex)
http://www.discount-hydro.com/ventilation.asp

the fan is pushing air past the bulb ? carbon filter inside ... to the fan .... past the light (through it) thought the duct up out top vent

laterz man

pics below was from a 250watt

all are super silver haze

 

[george j warner]

oh yer heres the link from my half kilo grow :]

http://boards.marihemp.com/boards/thd11x17195.shtml

results

http://boards.marihemp.com/boards/thd9x43360.shtml

http://boards.marihemp.com/boards/thd9x43413.shtml

http://boards.marihemp.com/boards/thd9x43421.shtml

laterz

 

[crftymofo]

I have always wanted to build one of these. I have thought about having a passive intake. Where the floor has a number of like 1" holes all over. Figure it would be good to have the air flow up through the plants would help them. and most of those cabinets have a space under the floor. Think it could work?

 

[george j warner]

maybe but you havent concidered about the tank ...it would block holes as it need to be right at the bottom ...

also you get all kinds of nasties coming up from/under the floor(fungus , disease , bacteria, pest ...spider mites) better to keep the in take about knee height .... you can have it at the back ..out of the way but because these system are normally up against walls you need a few ..and having 1 on the side is normally the easiest way ...