Airflow in curing chamber

[tempbond]

I plan to make myself a curing chamber in an 18 cubic feet side by side fridge,
in which I will either remove the center divide or make a few "windows" from on side to the other.

If I'm only able to make windows, what amount of airflow should I have between the two sides ? I'm going to install one or more computer fans for this purpose, but I'd like to know how many CFMs I need.

Also, how much airflow of fresh air do I need to get rid of the ammonia and other nasty stuff from the fermentation ? Again, how many CFMs ?

 

[deluxestogie]

CFMs? I don't have a clue, from a quantitative standpoint. I can say that my small kiln has no fan, circulates only by convection, and has no deliberate vents to the outside. The weather stripping used to seal the door apparently leaks enough. I start with color-cured leaf, rather than green, so I believe that there is only a minimal requirement for outside ventilation. Because the temp is generally above 125ºF, mold is unlikely.

If you are beginning with green leaf, as some do, then you will certainly need an adjustable vent.

Bob

 

[Chicken]

from d-stogies definition..

and your question, i'd say a small puter fan mounted at the bottom of the frig, pointing up,,,would be just enough for minimal air circulation, between the 2 section's.

good question by the way,,,,

 

[Jitterbugdude]

I played around with a fan last year, never used one before but thought I'd "experiment" Your cube is 18cf. Ask yourself, how often do you want a complete air exchange inside your kiln. 1 exchange an hour would be fine,so you would need a .3cfm fan. I do not know where you'd get something that moves that slow. Your best bet would be to just drill a 2 inch hole near the bottom and another near the top. This will give you a nice natural convection. If you end up with too much draft just cover part of the holes with tape.

 

[LeftyRighty]

I don't think just cutting a hole top/bottom will do anything to get air movement going, not when the whole thing is inside a closed box. You need something to push the air into that chamber. Those small computer fans really don't blow that hard - not enough to do much more than wiggle the leaves. Get one and you'll see !

Example: http://www.coolerguys.com/840556086970.html

You could mount the fan in a bottom hole in the wall between chambers, then experiment with the top hole. Starting with a much smaller hole on top will limit air flowing between chambers, causing back pressure, thus limiting air movement. Just have to experiment with hole size until you're happy with the results.

You will need to provide some sort of fresh air into the refrig, so the gaseous products of fermentation can exhaust. Cut/drill a hole near the bottom, and a smaller hole in the top - normal convection of hot air will push the air out the top. My kiln is about half your size, has 1/4-inch hole in the top, with a piece of duct tape loosely laid over the hole. Works for me. Someone reportedly used a piece of PVC pipe with a cheapo ball valve for the top vent - could easily adjust air flow out.

 

[Jitterbugdude]

I don't think just cutting a hole top/bottom will do anything to get air movement going,



You will need to provide some sort of fresh air into the refrig, so the gaseous products of fermentation can exhaust. Cut/drill a hole near the bottom, and a smaller hole in the top - normal convection of hot air will push the air out the top. My kiln is about half your size, has 1/4-inch hole in the top, with a piece of duct tape loosely laid over the hole. Works for me. Someone reportedly used a piece of PVC pipe with a cheapo ball valve for the top vent - could easily adjust air flow out.

Not sure what you are saying here. But the natural convection created by a 2 inch hole near the bottom and another near the top opposite corner will create enough convection so that you will not need to worry about a fan. You will still need to open your kiln daily to check water level etc.

 

[LeftyRighty]

If the holes are to the outside, yes.
I thought we talking about holes between the two chambers.

 

[DrBob]

for ventilation about .1 cfm or 3 air changes /day. or even simpler, open the door 3 times/day. same deal. My chamber has a 1/2" vent hole and works just fine
Dr.Bob

 

[Steve2md]

I wouldn't complicate things with fans and such, why not just use 2 crock pots and open the doors a few times a day. less drilling, and the fridge could be re used later for something else..(IE...BEEEERRRR) just my 2 bits

 

[LeftyRighty]

the kiln needs to be vented, unless it's one of those that just leaks a lot.
Unless you have a thermostat control, it's difficult to get and keep the proper temp with just the crockpot controls. Of course, you could keep opening the kiln several times a day to adjust the temp..... Venting gives another control on the heat, besides what is lost through the kiln walls.
Also, venting helps with controling the proper RH. With no vent, and the crockpot cycling on/off, you could end up with 100% RH and condensation on everything.


The problem with relying on opening the kiln to control conditions comes when you forget, get buzy or can't, or not home. Been there, done that..... had it go to 135+ degrees several times. Better to get it set up so it doesn't require frequent attention, and only needs occasional monitoring.

 

[Chicken]

the kiln needs to be vented, unless it's one of those that just leaks a lot.
Unless you have a thermostat control, it's difficult to get and keep the proper temp with just the crockpot controls. Of course, you could keep opening the kiln several times a day to adjust the temp..... Venting gives another control on the heat, besides what is lost through the kiln walls.
Also, venting helps with controling the proper RH. With no vent, and the crockpot cycling on/off, you could end up with 100% RH and condensation on everything.


The problem with relying on opening the kiln to control conditions comes when you forget, get buzy or can't, or not home. Been there, done that..... had it go to 135+ degrees several times. Better to get it set up so it doesn't require frequent attention, and only needs occasional monitoring.

i agree with this,,, most people are at work during the day and cant open it,

myself, last years kiln did get a lot of condensation, so bad it was literally running down the walls, and my baccy was very moist,

because i wasnt here to monitor it, { at work i was }

perhaps a small 4 inch fan mounted in the box, connected to the tube and assemblly a DRYER VENT WORKS ON with the flap on the end of the assemblly, when the fan is on { timer} the vent opens and exaust's the kiln,

^^^ im thinking of using this for my upcoming kiln,,,, it's going to be big,,,perhaps using 2 radiator type heaters,? heat lamps? and 2 crock-pots,

the kiln is allready built, soon im gonna start a thread on it, discussing ideas of how to perfect it, temp/humidity controllers. air circulation, heat placement and timers,,, e,t,c,

 

[Chicken]

heres the outside of it,

>

By chickenhawk434 at 2012-05-08
//

and here is where i built it at,,,the back4 feet of this camper, is all framed in,

>

By chickenhawk435 at 2011-08-01

i should be able to hang a lot of baccy in here at once,

 

[deluxestogie]

• The temperature should be controlled by a thermostat. It doesn't have to be particularly accurate.
• The humidity is ideally kept between 60 and 80% RH. It also doesn't have to be particularly accurate.
• My kiln is opened once every 3 or 4 days to replace the water lost from the Crockpot. This exchanges the air from time to time, and seems sufficient.
• It isn't complicated.

Bob

 

[Chicken]

• The temperature should be controlled by a thermostat. It doesn't have to be particularly accurate.
• The humidity is ideally kept between 60 and 80% RH. It also doesn't have to be particularly accurate.
• My kiln is opened once every 3 or 4 days to replace the water lost from the Crockpot. This exchanges the air from time to time, and seems sufficient.
• It isn't complicated.

Bob

what setting do you have your crock-pot on ,, low.. med. high???

 

[tempbond]

If you are beginning with green leaf, as some do, then you will certainly need an adjustable vent.

Bob

I'll only cure already air color cured leaves, as I'm growing tobacco for the sole purpose of making cigars.

 

[tempbond]

from d-stogies definition..

and your question, i'd say a small puter fan mounted at the bottom of the frig, pointing up,,,would be just enough for minimal air circulation, between the 2 section's.

good question by the way,,,,

I was thinking of using computer fans :

- one or two to circulate the air inside the fridge, from one side to the other, to balance the temp and RH evenly throughout the fridge

- one in my DIY humidifier (I was thinking of using a Honeywell cold air humidifier I already have, but since it' almost new and I don't want to ruin it, I'll make my own by using an extra wick/filter I have for that unit and placing it in a container filled with water halfway up the filter with a bigger computer fan pushing the air through it. I want to make the water container look like a dog's water bowl with a reservoir, one where the water is replenished as it is used. That bigger fan will be connected to a control unit, which will turn the fan on when the RH gets below a certain level and stop a certain level.)

- one to supply fresh outside air and at the same time exaust curing by-products

I hope I can find computer fans that run on 110V, so I'll be able to use the pre-existing inside lighting wiring of the fridge, instead of having to use an adapter for 9V or something like that and run new wiring. I'll disconnect the wiring to the compressor so the only thing working is the lighting when I plug in the fridge.

I dowloaded GoogleSketchUp today and I'm gonna try and make a model of what I plan to do, so you guys can take a look and see if I missed something.

And thank you for liking my question...

 

[tempbond]

Example: http://www.coolerguys.com/840556086970.html

That's one expensive fan ! It looks very durable though. I know an electronic parts supply store 45 minutes away from me where they sell all kinds of computer fans, for about 1 to 5$. They might be made out of plastic rather than metal, but that just means less rust.

 

[tempbond]

for ventilation about .1 cfm or 3 air changes /day. or even simpler, open the door 3 times/day. same deal. My chamber has a 1/2" vent hole and works just fine
Dr.Bob

If it only takes 3 air changes a day, I think the 2 hole convention method will be enough, no need for a fan.

 

[tempbond]

I wouldn't complicate things with fans and such, why not just use 2 crock pots and open the doors a few times a day. less drilling, and the fridge could be re used later for something else..(IE...BEEEERRRR) just my 2 bits

I found the fridge by the side of the road as someone was throwing it out. I don't even know if it works. I already have a beer fridge in the garage, so I don't mind modifying this one.

 

[tempbond]

the kiln needs to be vented, unless it's one of those that just leaks a lot.
Unless you have a thermostat control, it's difficult to get and keep the proper temp with just the crockpot controls. Of course, you could keep opening the kiln several times a day to adjust the temp..... Venting gives another control on the heat, besides what is lost through the kiln walls.
Also, venting helps with controling the proper RH. With no vent, and the crockpot cycling on/off, you could end up with 100% RH and condensation on everything.


The problem with relying on opening the kiln to control conditions comes when you forget, get buzy or can't, or not home. Been there, done that..... had it go to 135+ degrees several times. Better to get it set up so it doesn't require frequent attention, and only needs occasional monitoring.

I have 2 control units : one for the temp that will be connected to the empty crockpot and one for RH connected to the humidifier. I plan to set it up so I have to check levels the fewest times possible.