65% Beads - 62F & 80%RH - Beads are Dry

[Scimmia]

I looked up some info on these as used in museums before I got mine, and everything I found said they work on RH, regardless of temperature. Of course, they also talked about "reconditioning" the beads, where if they're at a specific RH for a long time, that's the RH that they try to maintain; nobody mentioned using the beads the way we're using them, as far as recharging them with water, some clear/some opaque, etc.

[fizguy]

[QUOTE=RLembke;807281]

Thoughts? Any physics majors in the house?[/
QUOTE]

I have a masters degree in physics, but I am not sure what is going on here. My thesis was in solid state so vapors are not my thing! Here are a few thoughts though:

You are treating the system as water and air. Perhaps the beads (I am not sure what they are made of) are more like a solution or a suspension. In that case the vapor pressure at equilibrium may be a function of the strength of the solution as well as the temperature. In that way RH could be held constant even if the temperature changes. I am thinking of what I read here:
http://www.cigargroup.com/faq/#6.1. It is about a mixture of salt/salt solution but may apply to the beads as well.

Not sure how helpful this is.

[RLembke]

I think you saw some of the same info I found earlier. To be honest, they weren't very technical in nature and I didn't trust phrases such as "regardless of temperature".

Here's one of the articles I found that approaches this from the technical side that made more sense to me.

http://www.gastechnology.org/webroot...ro.xml&bd=cpbs

[RLembke]

Originally Posted by fizguy

You are treating the system as water and air. Perhaps the beads (I am not sure what they are made of) are more like a solution or a suspension. In that case the vapor pressure at equilibrium may be a function of the strength of the solution as well as the temperature.

Thanks for the thoughts.

The beads are silica gel (solid, not a gel at all). They are essentially sand with millions of microscopic tunnels/craters. This gives an enormous surface area which allows them to adsorb so much water.

The theory of vapor pressure requires that you start with a closed system containing nothing but a single substance. In this case, water. At the given system temperature, there will be an amount of the substance in vapor state and an amount in liquid form. Here's a good link:

http://dbhs.wvusd.k12.ca.us/webdocs/...rPressure.html

Given the nature of salt compared to the silica beads, the similarity to the salt test makes sense. Salt at room temp will achieve an equilibrium within a closed environment. That said, I bet if you move that test to a cold temp and the reading will be different.......another something to test tonight. THANKS for the idea!

[Timberlake2006]

I apologize if any of this info has been said before, I just briefly skimmed this thread, but I'm assuming you know for sure that your hygro is accurate, if you don't know for sure then you might want to pick a calibration kit from cigarmony or hearfelt. Also if your humi is at 70 degrees and 70% humidity and then the temperature spikes down while the humi is sealed that might cause the humidity to spike for a little while until the beads can equalize it. Also I think your best bet for trying to stabilize your humi is to make sure that the Temp is constant first (at 70). If your still having problems then maybe you need more or new beads.

[Scimmia]

I did find one article when I was looking before which mentioned that they work differently than salt:
http://palimpsest.stanford.edu/waac/.../wn15-108.html

Ug, I've seen that vapor pressure page before, when we were having a discussion on relative/specific/absolute humidity and what to use for cigars. I think my head hurts again.

[RLembke]

Yeah, I really don't know that I meant to bring up the whole AH vs RH thing again...this is more of a discovery/disclosure of the operating apparatus of the RH Beads.

***Discussion as it relates to beads ends here....AH vs RH below***

The more I think about what we are really trying to accomplish with a humidor and a hydration system though, the more I'm on the AH side of this debate. Case in point...the weight of the cigars does not vary by temp. If there is a certain amount of water by weight that a cigar should have in it, then the environment needs to closely match that. Given a narrow band of temperatures, RH is perfectly fine for everyday measurement. However, given that cigars will always give up or absorb moisture to their environment, that environment should always have the proper amount of available water vapor, regardless of temp.

All I hear against the AH side of the debate is "DON'T DO IT. I'VE ALWAYS USED RH AND THEY ARE JUST FINE." I understand the locomotive forces of water changing at temp but that still doesn't mean that the cigar won't give up that moisture over time.

But I digress.....

[Viper139]

Place the hygrometer back in the calibration envelope and place the envelope in your fridge. I think you are having an issue with the hygrometer at the colder temps. If it calibrates correctly at the lower temp then at least the hygrometer can be trusted at the lower temp level.

You stated the beads were dry, I assume you mean that they are completely white or at least close to white?

[RLembke]

Viper -

Humidipak says right on their calibration envelope to keep the hygro/envelope at room temp, between 65 and 75F. Sounds to me like they are aware that their product has a temperature limitation. I would wager that product is also based on a set vapor pressure.

Yes, the beads will go completely white if I don't spritz them. When I do spritz them, the water is gone in no time.

Just checked it again tonight....62F & 82%RH. Makes since because I gave them a small spritz as a test again last night. RH is up another 2% from that.

[CanuckFan]

Originally Posted by RLembke

As I said above, being winter and damn cold here for the past several months, it's been very dry. My other hygro is on the first floor monitoring living conditions and this morning it said 38% and 68*. Since the basement is cooler than the rest of the house and not on the active-humidified HVAC system, I would imagine it's lower than 35%RH and somewhere around the 62* that the frigador is at.

The digihygro from Cigarmony is brand new a few weeks ago and has been calibrated with the Humidipak calibration kit.

During the summer when the temps in the basement are higher (around 70-75 depending on the month), I've had the same experience as you, stevie. RH was right around 65-67%.

I have a hunch that the temp is what's causing this problem. I'm going to try moving the frigador tonight to a climate controlled area of the house and let it breathe to lower the humidity and 'start over' in the new environment.

I'm looking for more technical information on this media but I am having problems. My hunch is telling me that the beads are trying to maintain the partial vapor pressure of water vapor, not necessarily the RH. Come to think of it, I don't know how that would be possible without some form of active control by the media - it would have to know the temperature and then adjust the partial pressure it is trying to maintain. This would mean temperature has a major factor. For every change of ~+20F the saturation vapor pressure of water vapor increase by a factor of 2.

I think your answer is here perhaps . Info from an ISOM site.

"Although humidity levels are almost always referred in terms of Relative Humidity, the actual value that is important is the amount of water vapor present in a given volume of air, known as Absolute Humidity. As air will hold varying amounts of water vapor at different temperatures, no discussion
of humidification would be complete without a discussion of temperature and it's effect on absolute humidity. Relative humidity is an easily measured value that relates the measured humidity to the maximum humidity that is possible at that temperature. Thus, 70% RH at 70 ºF is not the same as 70% RH at 80 ºF.

We are aiming to maintain the same amount of water (mgm/liter) around our cigars as seen at 70% RH at 70 degrees F (which is 13.15 mmHg water vapor pressure).

So, to be able to know what is happening with our cigars at temperatures other than 70 degrees F, we must use a table of adjusted relative humidity values to make sure that our humidors keep our cigars in the peak of condition.


Temperature, water vapor pressure and relative humidity required to equal 70% RH at 70 degrees (13.15mmHg).

Temp Water Vapor Pressure Relative Humidity


66 16.37 80.33%
67 16.95 77.58%
68 17.55 74.93%
69 18.17 72.37%
70 18.79 70.00%
71 19.45 67.61%
72 20.11 65.39%
73 20.81 63.19%
74 21.51 61.13%
75 22.25 59.10%
76 23.00 57.17%

It is not possible to attain an absolute humidity level that will keep cigars from drying out at temperatures below 60 degrees F. This observation will put to rest the fallacy that the refrigerator is a good place to store cigars. Not only do we have to worry about our premium cigars beginning to acquire the flavors from left over foods but the cigars will dry out and become essentially unsmokable. The freezer is an even worse place to store cigars. The humidity becomes virtually zero, and the loss of moisture from cigars will accelerate to produce a bone-dry smoke. "

I think this is why I'm headed for a wineador. Apologies if this is already in a previous post.

[Scimmia]

That chart has been posted many times, and is generally disregarded as bad info.

Do a search if you want to see the discussions.

[Viper139]

RLembke, has your addy changed since you bought your beads? If it has not I am going to send another 1/2 pound. I would like to see what happens with another group of beads.

[RLembke]

PM sent, Viper.

On a side note, I have moved the frigador to a HVAC-controlled area of the house. While moving things around, I discovered a few of my more prized sticks with fuzzy stuff on them...not good. The humidor is drying out right now and coming up to temp.

[Boston_Dude05]

Although the chart by CanuckFan has been dismissed multiple times, there seems to be some merit to it. The chart suggests that at lower temperatures, RH% must rise dramatically to compensate. Perhaps the beads are calibrated based on vapor pressure? This would explain why they are white. At the lower temperature, it must give off a lot more water vapor to reach the same vapor pressure at higher temperatures.

Perhaps Viper can comment on this?

Question to RLembke: How do your cigars feel between your fingers? Dry or wet?

[RLembke]

Honestly they don't feel that bad. At the same time, I'm not sure that I know overhumidified vs normal-but-on-the-high-side humidity. I have thought about doing a mini-study to test out what you are wondering......if I keep them at an absolute humidity equal to the humidity @ 70F/65%RH at a lower temp, would they smoke the same. I think that's a valid question but since my find of mold this evening, I'm no so interested anymore.

I think this discussion of RH vs AH is all relative to boundaries. RH works just fine between 65-75F. Don't go higher or the bugs will hatch. Go lower and you should probably judge things by AH but if the RH gets too high, mold is an issue. With all of those boundaries, we're still stuck between 65 and 75F and if RH makes sense, then why not stick with it.