Getting humidity up to 98% in a converted refrigerator

[ArnaudForestier]

I've touched on this here and there, but in the event others might have the same issue, I'm hopeful of getting some ideas tossed about on how to increase a refrigerator-turned-cave past the low '90's, to as high as a constant 96-98%.

What I have in there now are two humidifiers: 



The humidifier on the bottom, a wick-based, cool-mist humidifier, has an internal digital humidistat that tops out at 90%.  The top humidifier is also a wick, cool-mist humidifier, which is set to its low setting.  It has no humidistat and is constantly on.  The issue seems to be that once the inside air reaches around 91-92%, for the top humidifier, the evaporative property of the wick simply peters out; no more humidity can seemingly be squeezed out, even when it's constantly on.  I have read that the top humidifier, when set to "high," will add an additional moisture content, but of what I've read, this was for the purpose of humidifying a room with a customary RH in the say, 50-60's.  I don't know if maxing it will add anything more.

Additionally, even if it would add significantly more humidity, I wonder if the forced air itself from both units has an inhibitory effect.  Particularly when I've tried turning the top humidifier to the higher setting, it really blows out a ton of forceful airflow, undesirable in a cave.  The one thing I've banked on is breaking up the flow by directing the fans at solid surfaces, away from the cheese.  Not sure how effective it is in preventing a massive amount of airflow past the rinds, and consequent inhibition of the surface flora.

I also have a water vessel in back, with a rag covering the refrigerator outflow.  Not sure how much, if any, this adds in addition to the humidifiers. 

Given the top humidifier takes up so much room (that can be better used to stock wonderful wheels!), the minor contribution it seemingly makes above the nominal 89-90% of the bottom unit is pretty disappointing.  I'd like to get the RH up to 96-98%, as I have 2 beaufort in the cave, and intend on stocking more.  I can live with the tommes coming in at 89-92%, but for the long-aged alpines, no.

Any thoughts?

[mikeradio]

I am using a ultrasonic humidifier , with an external humidity controller in a larger 2 door cooler
and it could easily get the humidity that high.

http://www.sausagemaker.com/19001craneultrasoniccoolmisthumidifier.aspx

[ArnaudForestier]

Thanks, Mike.  I'd kill for a setup like yours.  As it is - my cave is in our bedroom, and I've pushed the limits of my wife's understanding (thank Gambrinus she's a fan of both beer, and cheese, my 2 biggest space demands, historically  ).  But I have actually been on the prowl for a cooler like yours, to be honest, since I've much bigger plans.

Can you tell me the make of your controller?  Hum 1?  Company?

edit:  sorry, just saw the link to the controller.  However, it, too, taps out at a maximum 90%, like most controllers I've seen.  The only one I've seen go to more is the RHC-1 Relative Humidity Controller, going up to a nominal 95% - with a 5% accuracy.  at $280, it's up there, so I was hoping of finding a cheaper way to get it going up.  I'm just wondering if perhaps there's a way to override the lower unit's internal humidistat, I can just leave it on and see what I end up with.

[mikeradio]

I am not sure how accurate the scale on the controller is, I currently have it set to 70%
and I am avg 85% humidity in my cave.  The blue line on the graph is humidity and everytime
the fridge runs , the humidity drops down to 68% the when the fridge shuts off it returns to 90%
I avg all the readings and it comes out at 85%, I am still testing and learning.  I think if I set mine
to the max I could get 100% no problem.

Your Cave is in your bedroom?  I am lucky to even get the garage for mine lol

[ArnaudForestier]

That's interesting, Mike.  I also wonder if the wick-basis of my humidifiers is the limiting factor.  I do recall having a small unit, like yours, and the humidity shot up to 100% overnight, and that was with a nano-unit.  Unfortunately, the little bugger died within a couple of days, so I returned to what I was doing. 

In the past, I had an issue with white dust, from my US humidifier.  You don't have an issue with this, I'm presuming?

Re: space usage, lol.  I've always been lucky...when I was a brewer, at one time, in our 1BR apt. in Chicago, I had a converted refrigerator with 4 taps, a smaller kegerator, and a beer engine, an authentic hand-pulled, English pub engine, with a cask.  Lucky she loves great beer, and cheese!

[mikeradio]

I have been running distilled water in it and have not seen any white dust yet.

[ArnaudForestier]

Ah, yep, that would do it.  Do you have a RO unit, or are you buying the water?

[FRANCOIS]

Honeywell has a number of ceramic based sensors that will go up to 100% in the temperature range of cheese.  See:
http://customer.honeywell.com/honeywell/ProductInfo.aspx/H7625A2010
and:
http://content.honeywell.com/sensing/prodinfo/humiditymoisture/009017_2_EN_w.pdf

You'd just need a simple low voltage controller for them.  Any controller with a single input and output should work.  You can use the output to turn on a relay that controls water or power to the humidifier.

[ArnaudForestier]

Thanks, Francois, I will tuck this away for a larger capacity (seems overkill, and at $461+, quite a bit more than I was hoping to spend for my little refrigerator, but great info for larger needs - thanks.)

[FRANCOIS]

If you are descent with electronics you can get an on-board sensor (second link) and solder up your own control board for a fraction of the $461 price.

[ArnaudForestier]

Unfortunately, I'm an idiot with just about anything like this, though an eager learner (as in, iratherfly's pid-controlled cheese vat).  I'm intrigued...and utterly clueless.  It seems you're saying you could control either a agri-misting system, or a humidifier, yes?

Looking at the second link, it looks like at the normal operating condition of the sensor would allow an RH of 100% at 50F, but only 95% at 55F and 90% at 57F or so - is this correct?

[FRANCOIS]

The temperature is in C, not F on that chart.  You could use the output to control anything you wanted.  I used to use it to open a solenoid that allowed water to flow to an agri-mister, and also used the same relay to turn on power to a booster pump.

[ArnaudForestier]

Ugh..I did say I was an idiot.  This looks fantastic, Francois, and to learn from this would be an added bonus.  Thank you.  Any idiot's guide you might know, that could give me some first steps?