Active humidifiers are for big humidors, stand-up cabinets, walk-ins, and such that have the room to hold them. I do not have a humidor large enough for even a small active system. These should have a fan that circulates the air in the humidor so the rh is the same throughout. The fan might not be on all the time, but it should cycle on and off.
I didn’t mention this in part I, but it happens that moist air is lighter than dry air so if you have a big humidor (doesn’t matter for the desktop or even end-table furniture types) and you don’t circulate the air, the water vapor it the box will float towards the top and the rh (remember “relative humidity” from Part I) near the top will be higher than near the bottom.
Active systems use (we hope) accurate and stable rh detection to determine the moisture level in the humidor and when it drops too low, the humidor begins to blow tiny water droplets into the air. These tiny droplets evaporate almost instantly (at least that’s the idea) and become water vapor raising the rh. Once in a while, depending on how often they must be on, you fill the water tank.
From what I can see all of these devices rely on the fact that in most homes, the rh of the air is lower than where we want it for our cigars. Active humidifiers do not have any means of lowering the rh in the humidor if it is too high. If you have to do this, an active de-humidifier is even larger than a small humidifier. Here’s a link to the smallest one I could find. I don’t think that these are generally good for cigars. Most operate by refrigerating hollow coils of metal (the one pictured in the link above says it doesn’t do this, but it doesn’t say how it works either). When air passes over the cold coils, its moisture condenses on them (remember carrying capacity and temperature from Part I) and then drips into a little container. The problem is that chilling the coils (or anything) takes energy and that produces heat. Along with water, heat is also extracted from the air passing over the coils. That means these devices pump out heat somewhere. Unless you have modified your humidor with a port and can connect it up to the de-humidifier to dump the heat outside the box, you will be warming your cigars perhaps more than you want. Of course if your place is both cold and damp all the time (perhaps you live in an Scottish castle?) and you have a walk-in big enough for one of these things, then the heat gives you a double bonus! Lucky there are passive-dehumidifiers that work pretty well for large-ish spaces like cabinets and even closet sized walk-ins. Here is one de-humidifier that might work for larger cabinets. Not exactly active, it uses silicon beads (see below) but also tells you when they have become damp enough to need drying. You plug this in to dry the beads out.
Passive systems include those picutred above. On the lower left of the first picture are all the variations I use. The stocking is filled with scent-free silicon kitty litter crystals. A bag of these is shown on the lower right. This stuff costs about $15 for 7 pounds at a pet store. ALL my use together comes to about 4 pounds, and since they never needs replacing (sometimes drying) I’ve got lots… This litter is just small silicon beads pictured in the glass ramekin in the middle of the picture. Notice how some of the beads in the picture are translucent. These are moistened beads and so this bottle (the bottles are always full but I spilled beads out to show them to you) is one of my “wet” or “breath out” bottles. I’ll get to that in a minute.
Now silicon beads happen to breath water-vapor in and out at about 65-70% rh. They weren’t designed to do this, they just happen to be that way. When the rh goes up, they absorb a little vapor, when it goes down, they release it. I put about 3 pounds of these beads into stockings (my girl friend is very generous with her old stockings) and then into my 40 quart coolidor (which holds about 20 boxes of cigars). Big stockings are stabilizers. I never wet or dry those, and they were all dry to start. I use the bottles (pill bottles with small holes drilled all over them and filled with beads) to bring the rh in the coolidor up or down. If the rh in my home is on the low side I put bottles (4-6) with moist (not soaking wet) beads into the coolidor. If it is high, I put bottles of dry beads in there. I keep separate bottles of moist/dry beads so I can just swap them out. To dry the beads, I dump them into a shallow pan and put them in an oven at about 250F for an hour or so until all the beads are solid white in color. I do this maybe twice a winter if the weather is really wet. I also use the smaller bottles in my smaller tabletop humidors. Same idea. Wet when the rh is low outside, dry when its high with a small sock of dry beads in the lid for a stabilizer. This isn’t a lot of work by the way. I only have to “do anything” about the beads every few months if even that.
Also in the picture are a couple of “DryMistat” sticks. These use ethelyne glycol and water (you fill them once in a while) and the mixture is also supposed to breath at about 70%. But the ethelyne glycol also evaporates (slowly) and so once a year or so I have to put more in the tube. To do this I buy a few once in a while and use them to fill the others. Evaporating ethlyene glycol is odorless and colorless so it doesn’t affect the cigars. I use some velcro to stick these to the inside of the lids of my humidors (second picture). Finally, I also use Boveda packs sometimes especially when traveling. I have a small travel humidor, but it only holds 4 cigars. Easier to take a quart sized ziplock that holds 10 cigars or more and throw a Bovida pack into it.
What I do not have to show you are Heartfelt beads. These are made from modified silicon beads with other mineral salts (like lithium chloride) bound up with them. The salt plus silicon combination does a better job of breathing and can take in, store, and let out more water vapor than the silicon alone. Because they are more efficient, you don’t need as much of it to do the job, but I do not know if they can be fully dried out for de-humidification purposes. I don’t see why not.
In summary here, silicon beads are cheap but you need a lot of them to get the job done. Heartfelt are more efficient, but I don’t know how much more and they are somewhat expensive. DryMistat sticks work but are also expensive. Bovida is supposed to be two way, but I don’t see it doing as good a job at pulling moisture out of the air as putting it in. Most cigar smokers are familiar with these devices. They all work pretty well to put water vapor into the air and most of the time this is mostly what we need because the inside of our homes, especially when we use any heat, usually has a lower rh than the outside. If you live in a place where the windows are open all the time, then the inside pretty much is the same rh as the outside. The odd thing happens if you cool your house. Cooling should raise the rh very high, but air conditioners are also de-humidifiers and pull water out of the air dumping it outside with their waste heat. Air conditioned air is often very dry!
So mostly we want to humidify. But sometimes we do want to de-humidify. We want to take [some] water vapor out of the air in our humidors. None of the two-way products above do this as well as they put water in. I have found this one product that does do that job (pictured). DampRid is sort of a flaky powder, anhydrous calcium chloride. ‘Anhydrous’ means it has no water in it. This stuff really sucks down moisture. I put a tablespoon in a bowl (why the bowl in a minute) and put that in a small tupperware container along with one of my digital hygrometers reading 68%. In about 6 hours the rh in the container was lower than the hygrometer would measure — my cheap hygrometers only go down to about 32%. According to the DampRid site it won’t pull the humidity down to zero but they don’t say where it stops. I know that in a small container (like a humidor) it would probably go pretty low.
DampRid is fantastic for dry boxing! Many smokers like to store their cigars near 70% rh, but smoke them closer to 60% because they burn better. The problem is that merely putting a cigar in an empty box (no humidifiers) won’t do anything if the rh in the air is higher than you want the cigar to be when you smoke it. A cigar can’t get drier than the air around it. The process can also take a while. Take a cigar in a 70% humidor and put it in a box where the air is 60% and the cigar can take a couple of days (depending on the temperature) to reach the lower humidity. A tupperware or small humidor with a little DampRid in a small cup and nothing else will dry a cigar for smoking in a few hours.
The reason you put DampRid in a little bowl or cup or something is that when the product pulls enough water from the air it liquifies (all the calcium chloride dissolves) and stops working. This dissolving process takes a while though unless your air is really wet. I see that a tablespoon of the stuff will regulate my humidor air for a few weeks at least maybe longer. If it ever goes completely liquid (it hasn’t come close in a week so far) I’ll try boiling off the water and see if I can reconstitute the stuff. Meanwhile, even if I can’t this is not an expensive product. $5 buys about a pound which should be enough for 6 months.
Meanwhile, what I’m doing is putting 2 tablespoons in a small ramekin and putting that in the corner of my humidors. I put 6 tablespoons (in a small mug) in my coolidor too. I left all the humidification devices in the humidors and coolidor because I want them to balance out the DampRid. The DampRid seems to pull the rh in all my boxes down about 5-7% (remember all my humidification stuff is in them too). Between the humidifiers and the DampRid, the environment balances out pretty well so far. It never seems to be “too high” any more, but it can sometimes be “too low”! If a few “very dry days” come along I’ll take the DampRid out of the boxes. Meanwhile I’ll keep monitoring them all and let you know what happens.
I’ve been playing with different passive humidifiers for years, but I’ve only had the DampRid in the last few weeks. It certainly works but I don’t yet know how convenient it will be in the long term. But none of this stuff, even all of it together, does a perfect job. Luckily, our cigars are pretty rugged. If the rh in your humidors floats around between 62% and 72% every day the cigars are doing fine.
My humidors are inexpensive Chinese made boxes. My 150 count humidor (for example) cost me about $100. They do OK, but a $2000 hand-made box (like this one) would probably do much better. Be that as it may, I’m not going to afford one any time soon. I’ll keep playing around with all of these products and let you know how it is going from time to time.
May all your cigars be good ones!