Why Not to Store Cigars in Refrigerators

[CalixEros]

I've seen a lot of posts about people asking if they can store cigars in refrigerators. For those of you who don't know how refrigeration works, I'll give a short explanation so everyone can understand why cigars do not belong in refrigerators.

The main components are an evaporator, compressor, condenser, and expansion valve. You have a refrigerant either in liquid or vapor form. Materials absorb a lot of (latent) heat when they change from a liquid to a gas (no temp change), much more than the (sensible) heat they absorb when changing in temperature.

At the evaporator, a mostly liquid refrigerant absorbs heat from the room it's refrigerating, enough to change it to a gas. It's usually put through coils with fans blowing air around them for better efficiency.

Then, the hot gas travels to the compressor and the gas is compressed to a higher pressure and heat is added. The refrigerant needs to be hotter than the ambient air or liquid that's cooling it or it will not cool.

At the condenser, the refrigerant is cooled and the gas changes to a liquid. It usually travels through a network of thin coils and has air blown over it or liquid sprayed on it to cool it enough to condense it.

Next the high pressure liquid goes through an expansion valve where the pressure is reduced and some liquid changes into a gas before it enters the evaporator.

So refrigeration relies on the interaction of temperature, pressure, and phase changes.

There are a lot of different types of systems, and some components work slightly differently depending on how the system is set up, but that was the basics


So how does all this pull the humidity out of the air?

At the evaporator, you have a cold refrigerant in contact with the hotter room. Humidity measures the amount of water vapor in the air. When the warm air comes in contact with the cool evaporator coils, it's cooled and the water vapor condenses onto the coils and collects into a condensate drain.


Somebody posted something about using a thermoelectric refrigerator a few posts down. As I understand, they work on the principles of the Peltier Effect (an electric current passing across two dissimilar materials creates a difference in temperature). I don't think this would create humidity problems because the electric current must be insulated, and would probably be insulated enough to prevent condensation. I could be wrong here, but if they did pull out humidity, that would mean the skin would be sweating on the inside of the fridge (where else would it go?). People probably wouldn't like a fridge like that...

 

[Allofus123]

Thermo electric works. It does not draw down on the humidity. It is the type of cooling system used by all of the well known cabinet humidor makers.

As to reg refrigeration. Yes, when the compressor is running it will draw down on the humidity inside. Couple of things to consider.... in order to convert a regular fridge you need to be able to regulate how often the fridge cycles as most do not have a thermostat that will keep it in a 60-70 degree zone. You can buy a temp controller for about $50-$60 that you plug the fridge in and set the temp you want the fridge to cycle on. It works on about a 3 to 4 degree spread. At one time I had a fridge set up that cycled on at 67 degrees and shut off around 63-64 degrees. This had the compressor running about 30 seconds. Using a high/low digital hygrometer I would get a low humidity reading of near 35-40%. Within 2 minutes of the compressor cyling off the hygrometer would already be reading 55% and climbing. Within 5 minutes it was back to the 64/65%. Now I speculate that the air in the humi had already returned to 60-65% within a short time after the compressor kicked off and the Hygrometer took five minutes to "catch up".

My advice is that if you plan to use a regular fridge (or one that uses a compressor) to store everying inside of cigar boxes. I stuck the hygrometer inside of a cigar box while the fridge cycled on and off for a day and the lowest humidity reading was 55%. Now we're talking about cigars stored inside a box being subjected to 55% humidity for 30 to 60 seconds per cycle. IMO and experience.... not a problem.

 

[kro77]

So most of the large cabinet makers user thermoelectric? Do they use peltiers or something else? Has anyone created a kit to insert into a humidor, or is it kindof impossible because there is no place to vent excess heat or cold when the unit is running. I wonder if a single unit could be built that could regulat heat and humidity. Hmm, at times I whish i had some circuit design experience to build something. The Peltiers are pretty easy to put in, the challenge i thing would be venting the excess temp, and the sensors, but doable over all. I will google some more and see what i can find.

- K

 

[morenoloco]

So most of the large cabinet makers user thermoelectric? Do they use peltiers or something else? Has anyone created a kit to insert into a humidor, or is it kindof impossible because there is no place to vent excess heat or cold when the unit is running. I wonder if a single unit could be built that could regulat heat and humidity. Hmm, at times I whish i had some circuit design experience to build something. The Peltiers are pretty easy to put in, the challenge i thing would be venting the excess temp, and the sensors, but doable over all. I will google some more and see what i can find.

- K

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Viper139 and I were having a discussion about this... he seems to think that the Peltier unit is the way to go, and made some excellent argumets for it.

Right now he's dealing with some family issues, but when he's less busy, he'd probably be more than happy to answer any of your questions.

He is the one that sells Climaxx beads, and I had asked him about the possibility of ordering Climaxx beads that maintain a lower humidity. Depending on where you live in the country, it makes a difference... I live about a block from the beach, so humidity can be problematic.

 

[IgwanaRob]

Viper is Heartfelt beads, Climaxx used to be Vern's product - basically the same thing, just different product names

 

[CalixEros]

In thinking about it a little more, the humidity is pulled out of the air due to the temperature difference and dew point. It has nothing to do with how the temperature difference comes about. If you're keeping the refrigerator close to room temperature, you probably won't have a problem since the temperature differential is small. If you keep a thermoelectric fridge at 65 outside in a South Carolina summer it WILL pull the humidity down and condensation will form. I don't know what was wrong with me the other night (tired, hungover, something like that), but all that matters is the temperature difference. If you had a regular fridge you could keep at 65, it would not pull humidity out of the air if you kept it in your house with a temperature of 65.

The colder the air is, the less grains of water vapor it can hold at saturation. If the air is oversaturated for the particular temperature, water vapor will condense regardless of how you pulled down the temperature.

 

[atuck]

I am going to use a big freezer basically as a big a$$ coolerdor. I will use 1 or 2 Oasis IIs for humidifiers and I'm thinking about using one of THESE to control the temp. And I have plenty of Spanish cedar that I bought on Ebay to line it with. I am doing this because I want to get rid of all those damn coolers in my guest shower.

 

[gandolf565]

What a great thread!

Humidity changes due to conventional refrigeration should be small because the run time of the compressor should be short enough that condensation will occur on the evaporator coil, but not long enough to drain off. When the compressor stops that condensation will evaporate and re-humidify the air.

The above is why one should never use a 4 ton air conditioner unit in his house if a 2 ton is the correct size. It will run more, which seems wrong, but comfort is a function of temperature and humidity.

As for the peltier devices, my brain is really turning. If you limit the current going to the junction, or cycle the current, you could get gnats a**
temerature control, with very little or no effect on humidity. The idea is to keep the cool side of the junction just cold enough to control temperature, but not cool enough to condense the moisture in the humidor.

I feel an electronics project coming on...