NGB (OG) Cabinet Modifications - Thoughts/Ideas/Suggestions?

[banjobrain]

• UPDATED 04/19/09 - Now that my seeds have popped, please check out this link if you are interested in following my grow: Banjo's First Grow - Sadhu - Spring 2009 - NGB Style 250w MH/HPS DWC

• The pictures of the cabinet during construction begin on page 6. Pages 1-5 are discussions about design and the best way to approach this cab and the modifications I wanted to make. Pages 6-9 were discussions about lights, construction, etc.
  

I hope you enjoy this thread and that those who are looking to construct a cab may find the information contained here helpful.

Thanks!
​

As I mentioned before, I plan on constructing the NGB box according to the Marijuana Stealth Cabinet (NGB) - as seen on OG plan listed above.

I am planning several modifications and would like some input:

• Adding 12-16 inches of height to the box (???)
  • I want to be able to have the option to (try) grow some larger/taller strains, specifically some sativas.
  • What would be an ideal height if I wanted to this?
• Increasing intake from 1" to 2"
• Running 250 hps instead of 150 hps

I am wondering:

• Because I am increasing the size of the box and the intensity of the light, should I run a larger fan than the 150 cfm Dayton Pole fan specified in the above directions?
• If so, what would be an ideal size?

I plan on making a carbon air filter similar to the one listed here:
http://icmag.com/ic/showthread.php?t=31605&page=1

Any other thoughts or suggestions?
​

This is going to be a slow process. I was hoping to get some of the materials and tools to build this weekend, but I have to replace the clutch in my truck.

I will wait until I get the cab built before purchasing lights, but am thinking about a HTGSupply 250w HPS with a Supernova reflector.

http://www.htgsupply.com/viewoption.asp?ID=34

I want to do this, because I don't want to rewire a hope depot security light ballast. I'm intellegent, but I'm not an electrician and I'm worried about wiring something incorrectly and burning my place down. Besides, the above reflector (and included vent flanges) would allow an an easy and clean way to vent out to the utility room.

Main concerns, however are:

• What might be an ideal height for this box?

• With increased box height and increased light - do I need a more powerful fan that can push/pull more cfm?

 

[Guest]

I can't advise you on the height; this depends on the strains and how big you're going to let them grow (training methods), with which I have no experience.

I'm working on a NGB-style design now with a 250W, but it's going to be shorter than what you're planning. A larger box will have more cubic feet to move, meaning a more powerful fan to meet the minimum 5 exchanges/minute, and the heat from the light may make you want to exceed that, depending on how you cool the light. I'm planning to use a DIY cooltube, but any sort of air cooled hood should make a big difference in a small space based on the advice I've received.

I'm a novice at this, so I'm not going to go on passing all the advice I've received before I've tried it, but we are thinking of a similar setup, so I wanted to wish you good luck.

~A

 

[K.J]

As I mentioned before, I plan on constructing the NGB box according to the Marijuana Stealth Cabinet (NGB) - as seen on OG plan listed above.

I am planning several modifications and would like some input:

• Adding 12-16 inches of height to the box (???)
  • I want to be able to have the option to (try) grow some larger/taller strains, specifically some sativas.
  • What would be an ideal height if I wanted to this?
• Increasing intake from 1" to 2"
• Running 250 hps instead of 150 hps

I too made some major modifications to the NGB design. I can't recall the original specs, but I'm pretty sure we added at least 12" to the height, if not double that. We're using 1" ventilation holes in the veg room, but 2" between the interior walls. We also are using a 250w HPS in the flower room. It sounds like you're on the right track to me.

As for the fan, we're using a 256cfm fan; maybe a little overkill, but we think it'll work fine since we're also pulling through a large carbon filter.

 

[DiscoBiscuit]

The added height will give those sats more room but the bottom three feet or so will get little to no penetration. That said, extra height makes maintenance easier. If you get a chance, check out Pipedream's thread (150w hps club). He has a tall cabinet and grows Jamaican sats. Most of the pics of his grows are at the start of the thread.

 

[banjobrain]

I'm pretty sure we added at least 12" to the height, if not double that. We're using 1" ventilation holes in the veg room, but 2" between the interior walls. We also are using a 250w HPS in the flower room. It sounds like you're on the right track to me.

As for the fan, we're using a 256cfm fan; maybe a little overkill, but we think it'll work fine since we're also pulling through a large carbon filter.

Ok, so you added height, but left the holes the same diameter? Your intake holes are 1" into the mother room? 2" into the veg/flowering room? Did you route pvc around the room and direct it beneath/beween the two plants?

I was thinking that I would house the fan in the "utility" chamber to vent and cool, and once things started getting stinky I would filter it via charcoal as I mentioned in my first post.

KJ -

• How is your fan set up?

• How are you filtering? Where is it located?

• Do you think a large filtering system like I'm thinking is necessary?

I plan on doing this in a 1 bedroom apartment where smell is more of a concern than anything.

 

[K.J]

Ok, so you added height, but left the holes the same diameter? Your intake holes are 1" into the mother room? 2" into the veg/flowering room? Did you route pvc around the room and direct it beneath/beween the two plants?

Same diameter, but we're adding more of them. We'll have them coming in both the veg room and the flower room, about 12 total. The PVC will be routed around so that we can direct the air strategically to certain places in the cab.

KJ -

• How is your fan set up?

It's a CanFan 6" and it's set up in the utility room (or, will be when it's done). So the air comes into the veg chamber via the 1" PVC, then through the center wall via 2" PVC and into the flower room. From there it goes in the open end of the air cooled light hood and from there out the other end through ducting which takes it into the utility room. The utility room houses the Can33 carbon filter, which is connected to ducting, into a 6" muffler, and out the back wall via a direct connect of the muffler to the back wall.

Make sense?

• How are you filtering? Where is it located?

See above.

• Do you think a large filtering system like I'm thinking is necessary?

I plan on doing this in a 1 bedroom apartment where smell is more of a concern than anything.

I think your plans are spot on. Just make sure you measure you growing area and match that up with the appropriate fan. You're going for negative pressure here so you can control the flow of the air.

 

[banjobrain]

Same diameter, but we're adding more of them. We'll have them coming in both the veg room and the flower room, about 12 total. The PVC will be routed around so that we can direct the air strategically to certain places in the cab.

Cool. I like that idea and may think about different ways to route my pipes.

It's a CanFan 6" and it's set up in the utility room (or, will be when it's done). So the air comes into the veg chamber via the 1" PVC, then through the center wall via 2" PVC and into the flower room. From there it goes in the open end of the air cooled light hood and from there out the other end through ducting which takes it into the utility room. The utility room houses the Can33 carbon filter, which is connected to ducting, into a 6" muffler, and out the back wall via a direct connect of the muffler to the back wall.

Yup. That makes sense. I'm planning on using 4" ducting. Any noticeable benefit to using 6" ducting that you can think of?

Just make sure you measure you growing area and match that up with the appropriate fan. You're going for negative pressure here so you can control the flow of the air.

Can you clarify what you mean my matching it with the appropriate fan?

• I don't understand what you mean by negative pressure and controlling the flow of the air...

Thanks KJ. This is turning out to be a great forum for idea sharing. I am really excited to get this moving. It's not going to happen overnight, but I'm confident that by doing it right the first time will pay off in the long run.

 

[K.J]

Yup. That makes sense. I'm planning on using 4" ducting. Any noticeable benefit to using 6" ducting that you can think of?

Not that I know of. It just happens that my light hood and fan have 6" connections.

Can you clarify what you mean my matching it with the appropriate fan?

Just that you have a fan that moves enough CFM to match the size of your cab (your fan should be able to replace the air in the cab about 3-4 times per minute). You'll have to search these forums for the formula, because I'm no physicist.

• I don't understand what you mean by negative pressure and controlling the flow of the air...

Negative pressure means that the fan is pulling so much air, that it pulls the doors closed. It also makes sure that the only air going out of the cab, is going out the filter and not through cracks in the cabinet seams.

 

[FreezerBoy]

I want to be able to have the option to (try) grow some larger/taller strains, specifically some sativas.

The key to sativa's in a small box is horizontal growth. While plant 1 (Thunk) seems much "larger" than plant 2 (Destroyer), there's only a 5g difference; 120 vs 115. My Thunk was a constant battle keeping stems out of the lamp as the lamp was quickly forced to the top of the cab.



Destroyer colas were 19 inches BUT, they were only 6 inches "tall" because I grew them sideways. Note the twist tie at 3 O'Clock in pic 3? I had to let it up to take the shot. Added bonus, this saves me a foot of vertical space inside the cab for a better fan/scrubber combo I had no room for before.



With a 250, there will be much greater growth than the standard NGB. Consider accommodating this growth with a larger footprint rather than greater height that would leave lower buds underlit.

 

[FreezerBoy]

For figuring fans fan-intake calculator

 

[banjobrain]

The key to sativa's in a small box is horizontal growth...With a 250, there will be much greater growth than the standard NGB. Consider accommodating this growth with a larger footprint rather than greater height that would leave lower buds underlit.

Great idea. I will reconsider my plans - take away some of the height and add to the width. Thanks for the thoughts and pics.

As far as the fan calculator and that following thread is concerned...I understand the chart and how to figure it out, but I have a couple of questions...

• It seems like the fan-intake calculator specifies that you should have a tremendous amount of intake.

• From what some people wrote, it sounds like you can get away with using a higher powered fan with a little less intake, is this correct?
  • My concerns might be burning out the motor in the fan if I don't have enough intake...
• Is it possible to have too much intake?

 

[K.J]

• It seems like the fan-intake calculator specifies that you should have a tremendous amount of intake.

• From what some people wrote, it sounds like you can get away with using a higher powered fan with a little less intake, is this correct?
  • My concerns might be burning out the motor in the fan if I don't have enough intake...
• Is it possible to have too much intake?

I imagine at some point you can cross the line into "too much intake" territory. But based on my research here on the forums, you want double the intake surface area as you have for the exhaust area. So our case we'll be doing six 1" PVC pipes in the veg and 6 1" PVC pipes in the flower, with 2" PVC between the interior walls. This is twice the area of our 6" exhaust port in the utility room where all of the air exits.

 

[banjobrain]

So our case we'll be doing six 1" PVC pipes in the veg and 6 1" PVC pipes in the flower, with 2" PVC between the interior walls...

So if you have intake in the flower room, how do you do that and keep the light out?

Would you run it the same way you're planning on running it in the veg/mother room?

 

[Cozy Amnesia]

Scrap the PVC pipes for ventilation and employ the air-duct/light-trap of the future!

Air enters the wall in the veg chamber here:

And then enters the flower chamber out the backside of the wall here:

The wall is hallow on the inside:

It works perfectly. Air enters the veg chamber from outside the box in the same way. If you'd like more construction pics, I got em so just ask!

 

[K.J]

So if you have intake in the flower room, how do you do that and keep the light out?

Would you run it the same way you're planning on running it in the veg/mother room?

We won't run it identically, but we'll make sure there are enough bends in each pipe to trap any incoming light (they're entering from the bottom, so not much light will get into them anyhow).

 

[jordas]

I like that hollow wall idea.......very nice!

I did something similar in between a large closet that I partitioned in half and used a dual wall to allow air to pass from one area to the other but block the light........I had to paint mine flat black because a small amount of light from the clone side reflected off of the wood and could be seen from the flowering side.....

 

[FreezerBoy]

So our case we'll be doing six 1" PVC pipes in the veg and 6 1" PVC pipes in the flower, with 2" PVC between the interior walls. This is twice the area of our 6" exhaust port in the utility room where all of the air exits.

While the illo uses 9 holes, the idea is the same. Six 1 inch holes do NOT a
single 6 inch hole make. To double the 6 inch exhaust, you'll need Seventy Two 1 inch holes.

 

[K.J]

While the illo uses 9 holes, the idea is the same. Six 1 inch holes do NOT a
single 6 inch hole make. To double the 6 inch exhaust, you'll need Seventy Two 1 inch holes.

Huh? Can you run that by me again? How does 6 1" holes not make the same surface area as a single 6" hole? I mean, it may not be an exact equivalent, but for our purposes isn't it "close enough for grenades"?

So are you saying that our plans are screwed? We have a single 6" hole that will be the final exhaust point for our cab and six 2" holes (I thought they were 1" when I first typed the post you referenced) for intakes. Are you saying we'll need dozens more intake holes? That makes no sense to me.

EDIT: I revisited some info off of another thread called "Understanding Air Flow". Based on this data, it looks like our six 2" intakes will be enough to match our single 6" exhaust point. Do you disagree?

 

[Guest]

Based on this data, it looks like our six 2" intakes will be enough to match our single 6" exhaust point. Do you disagree?

The area for circular holes would be pi * (radius)^2, no?

so for 6" diameter, 3" radius: pi*(3")^2=9pi in^2
and for 2" diameter, 1" radius:6*pi*(1")^2 = 6 pi in ^2

I can't speak to the truth of the 2:1 law, but maybe this helps, if the people making that law did it by area.

Edit: I would think they must have for it to make sense.

 

[K.J]

The area for circular holes would be pi * (radius)^2, no?

so for 6" diameter, 3" radius: pi*(3")^2=9pi in^2
and for 2" diameter, 1" radius:6*pi*(1")^2 = 6 pi in ^2

I can't speak to the truth of the 2:1 law, but maybe this helps, if the people making that law did it by area.

Edit: I would think they must have for it to make sense.

I'm kind of a math idiot. Can you translate that into English for me?