The Cab Club

[m00nchild]

Yeah, so I've been trying to figure out what's going on with my cab, to no avail. The flowering chamber, underneath the 250, is staying at about 5-6 degrees (F) above ambient. But right above that, in the veg chamber, under the 52 watts of CFL's, it's staying at about 15-20 degrees above ambient!! This is not good, and I'm sure I'll figure it out, but DAMN!!! The only other possibility is that my thermometer is wrong. I guess that is possible, as it is very old.

I've checked for air leaks, and this thing is VERY air-tight, other than a few pin-prick holes where I can see light leaking out. This is mostly underneath the door hinges, and it is negligible. So there is no problem with the airflow, and I can hold a piece of paper up to the intake at the bottom of the cab, and it sucks up to it. So the airflow is moving.

But for some reason, once it gets up above the flowering chamber and into the CFL chamber, the heat just hangs out there. I'm going to try installing some small circulation fans tonight, but if that doesn't work, I'm at a loss as to what the problem is. The only thing I can figure out is that I simply don't have enough of an intake for proper ventilation. Using only one 8x8 darkroom louver might not be enough?

Wish me luck, because if this doesn't work, I'll probably have to make a separate cabinet for vegging, and that beats the whole purpose of designing an all-in-one cab!

 

[Kelly.]

...

 

[simon]

For your amusement, the main cola of the Monster next to ~2 liter milk jug. I'm still amazed by what can be grown in a box.


Simon

 

[gdbud]

Simon,
I see now, why you use 1 gallon jars for curing. Do you have problems with mold when drying/curing a bud that size?

 

[simon]

Simon,
I see now, why you use 1 gallon jars for curing.

<grin> I use 1gal jars, because I run a 3.8'x12' room with 2400w aside from the boxes. It averages 2-2.5oz (dry/cured) per ft2. 3oz per ft2 if I grow Chronic. I use one of my cabs for test grows and to take-up the slack from the main room, and the other for occasional vegging.

Do you have problems with mold when drying/curing a bud that size?

I cut it down substantially. The plant was grown to test its commercial viability. While the yield was there, the bag appeal was not, so I'm not keeping the pheno. I biggest colas I cure are ~10"/1oz each and only for personal use. I keep them big for longterm storage. Have you read the curing thread in my sig? Never a problem with mold, because I measure the RH inside the jars.

Simon

 

[m00nchild]

Okay I think I figured this thing out. Long story short: when using darkroom louvers, remove 2 of the layers, and the thing is still virtually lightproof while letting twice the amount of air through.

The problem all along was with the darkroom louvers being too constrictive, and I did all my calculations without taking this into account. Sometimes I suck. But oh well, I think I have the temps stabilized at the 87 to 89 degree mark, which is fine for Mandala genetics.

Pics coming soon, when I stop being lazy.

 

[gdbud]

Have you read the curing thread in my sig? Never a problem with mold, because I measure the RH inside the jars. Simon

Yes I have and thank you for a great read.
I have one jar that is curing at 61% RH and three that have dried out to far to cure 58-56%.
what a difference in smell over the one that is curing over the other jars.

 

[barth]

For your amusement, the main cola of the Monster next to ~2 liter milk jug. I'm still amazed by what can be grown in a box.


Simon

HA i roll joints that big!!! Just takes me a week to smoke it. LOL

 

[5th]

Air is going to take the path of least resistance. Which this means for you is that all of your air flow is going through the open end of the Y and none is going through your light.
What you need to do is damper the air flow through the Y. Place a piece of cardboard that has a 2" hole in the center over the open Y and see how your heat problem is.

No problem anymore.

Took your advise to reduce the size of that hole and I put my 10x7 passive intake back into the back of the cab with a furnace filter on it.

Ambient 68
Cookin' 82

Many thanks and Rep+

...now lets bubble some clones...

 

[TheGhost]

Cool thread no better place than a thread like this spread some info and learn something new.

Here's my old beast - 5+ years and still going strong on a 65 day turn around.

https://www.icmag.com/ic/gallery/showphoto.php?photo=199369&ppuser=12123

 

[gdbud]

5th, I'm glad that I was able to give you a hand with your solution.

TheGhost, I can only hope that my cabinet will be running for 5+ years. Good Job.

 

[simon]

Yes I have and thank you for a great read.
I have one jar that is curing at 61% RH and three that have dried out to far to cure 58-56%.
what a difference in smell over the one that is curing over the other jars.

That's really great to hear.

Simon

 

[m00nchild]

Okay, now that my temps are worked out, here are my updated pics:










As you can see, what I ended up doing is I increased the amount of airflow by opening up the intake and "pass through" holes. In addition to this, I ended up taking each of the darkroom louvers and splitting them up to be 2 layers thick. So now I have double the amount of area. Of course, it reduces the lightproofing a little bit, but it's practically negligible. Less air is now being restricted into and through my cabinet because it is going through 2 layers of the lightproofing instead of 4 layers.

Everything seems good now! Temps are about 87 to 89 in both veg and bloom areas, which is pretty cool, as I thought the veg area would be slightly warmer, since it's getting the HPS heat. I have a total of 4 hashberry seedlings which I'll be vegging out and taking clones from, but I also have a fem super lemon haze seedling that I will probably be putting immediately under the HPS in a couple of weeks. I can't wait!

 

[bloodlock]

Alot of very nice and productive cabs in this thread, good work guys!

Here are my Ikea cabinets:



Veg/cloning:
1 x 125w 6500k CFL


Flowering:
2 x 125w 2700k CFLs with reflectors

 

[simon]

In addition to this, I ended up taking each of the darkroom louvers and splitting them up to be 2 layers thick. So now I have double the amount of area. Of course, it reduces the lightproofing a little bit, but it's practically negligible. Less air is now being restricted into and through my cabinet because it is going through 2 layers of the lightproofing instead of 4 layers.

I use 2 panels of each louver, as well. If the mounting surface is facing a wall or the floor, essentially any surface that isn't in direct view, the light seepage is very small. With a furnace filter in place, it's even smaller. I'm glad you got the issue sorted.

Simon

 

[DiscoBiscuit]

Great thread. Tweaking grow cabs can be a frustrating job but places like this make it easier for everybody.

 

[m00nchild]

Thanks simon. Do you find that the furnace filter blocks a lot of the airflow, or is it negligible?

 

[DiscoBiscuit]

A filter is only part of the resistance air-flow will encounter in a cab, ie scrubber, ducting and or hardware in the air path. 2x passive intake might be more than necessary but will maintain negative pressure and fans don't strain when the cab doors are closed.

Cheap fiber filters probably won't be noticeable but hepa (or something that blocks up to ~90% of particles) might have to be changed more frequently.

I can get away with used dryer sheets. If the temp climbs a degree or three unexpectedly, I assume it's another dirty filter. My cab is on a hard floor and is probably dustier than if it were sitting on carpet. This is about a month of accumulation.

 

[simon]

Thanks simon. Do you find that the furnace filter blocks a lot of the airflow, or is it negligible?

As with everything I design, the cabs are overkill - big lights, big fans, big filters, big ductwork, lots of intake area. As such, furnace filters have no noticeable impact. The boxes, individually, always run 1-2F above ambient with 600s. With 400HPS', the boxes run at ambient.

Simon

 

[m00nchild]

Thanks simon.

Dang that's a lot of dust Disco!! Yuck! I guess I need to go cut me some furnace filter!