How an electric humidor works: climate control, capacity and maintenance
An electric humidor is a storage cabinet that actively regulates humidity and temperature for cigars rather than holding them passively. This article explains how that regulation works technically, which properties determine the stability of the internal climate, and what maintenance comes with it.
Cigars respond to both moisture and temperature. Swings in humidity lead to mould or drying out, and neither can be reversed. Temperature also affects the ageing process. Where a traditional humidor works with passive humidification, an electric humidor uses a control system that measures continuously and corrects.
What this article covers:
- how active humidity control differs from passive humidification
- which properties determine the stability of the internal climate
- which types of electric humidor exist and how they differ technically
- how capacity relates to storage time and consumption
- how temperature and humidity control work in practice
- what odour and ammonia removal do
- what maintenance an electric humidor requires
This article is intended as background and explanation. The current range is in the category electric humidors.
1. What active humidity control does
The difference between a traditional and an electric humidor lies in how the moisture level is maintained. Traditional humidors use passive humidification: a humidifier releases moisture and the cabinet holds it. There is no feedback. An electric humidor measures the humidity and corrects actively.
That feedback comes in two forms. Simpler models use a P control system, which corrects on the deviation from the set level. More extensive models, such as the Raching MON series, use a PID control system, which also weighs the rate and the accumulated deviation. The practical difference is precision: a PID system overshoots less and recovers faster.
That precision is not cosmetic. Swings in humidity lead to mould or drying out, and a collection that has once dried out does not come back. The smaller the deviation, the more stable the storage conditions over longer periods.
Temperature control follows the same principle. Cigars keep ageing, and that process runs differently under fluctuating temperatures than under a constant one. A stable climate therefore encourages flavours and aromas to develop over time. For anyone storing cigars for years that weighs more heavily than for someone smoking through their stock within months.
In practice, most electric humidors show the current humidity and temperature on a digital display on the outside. That saves opening the door, which in itself already disturbs the internal climate. For storing loose cigars, incidentally, a box generally gives better results than loose storage.
2. Which properties determine storage quality
In an electric humidor, five properties together determine how good the internal climate is and how much work the maintenance takes.
- Capacity. A cabinet sized too tightly for the quantity of cigars it holds circulates less air and reacts more sharply to the door being opened. Capacity is expressed in litres of volume in practice, because the number of cigars depends heavily on the format.
- Interior material. Spanish cedar contributes to moisture retention and influences the aroma of the cigars. It is therefore not just a finish but a functional part of the storage system. More on this in the article about Spanish cedar in cigar storage.
- The humidification system. This is the part that determines most of the maintenance. Systems with a membrane filter take up distilled water through a membrane that has to be replaced periodically. Systems without a membrane filter, such as the Raching MON series, have no such maintenance.
- Air treatment. Odour and ammonia removal are separate functions that are not present on every model. What they do exactly is covered in chapter 6.
- The compressor. Compressors designed for wine and cigar storage, such as the Embraco compressors in the Raching models, use copper lines. These offer better corrosion and heat resistance at the moderate cooling capacity needed for this purpose. A compressor from an ordinary refrigerator is tuned for different use.
3. The different types of electric humidor
Electric humidors come in four broadly distinguishable types, differing technically in capacity and in the accuracy of the climate control:
- compact electric humidors the size of a small refrigerator
- large electric humidor cabinets
- commercial electric humidors
- humidors combined with wine climate cabinets
3.1 Compact humidors
Compact humidors generally hold up to around 500 longfiller cigars in robusto format. They usually work with a P control system. For anyone keeping a modest stock and smoking through it within a reasonable time, that accuracy is generally sufficient.
3.2 Large electric humidor cabinets
Cabinets can hold thousands of cigars and are built for long-term storage. They more often use a PID control system and therefore hold a steadier climate than compact models with P control. That difference weighs more heavily the longer cigars are stored, because small deviations accumulate over years. Some models also have a sommelier drawer; what that does is covered in chapter 8.
3.3 Commercial electric humidor cabinets
Commercial humidors are built for retail, where the door opens far more often and the volume is greater. They are more robustly executed and have heavier humidity control systems to absorb those disturbances. Private collectors with a substantial collection end up with this type for the same technical reasons.
3.4 Humidors combined with wine climate cabinets
A combination cabinet houses two separated climate zones: one at cigar conditions and one at wine conditions. That is technically different from a humidor with an extra compartment, because both zones have their own temperature and humidity setting. Wine and cigars call for different storage conditions.
4. Capacity in relation to storage time
Capacity is not a standalone figure but a ratio: how many cigars pass through each year, and how long they need to age. Someone smoking a given quantity annually and resting it for three years is holding roughly three vintages at once. That calculation determines the volume needed, not the current stock.
There is also a technical reason not to size too tightly. A fully packed cabinet has less air volume to absorb swings, so opening the door has a greater effect on humidity and temperature. Some headroom acts as a buffer.
Besides the contents, physical placement matters. Electric humidors dissipate heat along the back and top, so that space must stay clear; building in is possible provided heat dissipation is assured. The door on most models opens to the right and needs up to a centimetre of side clearance to stand at a right angle. A socket within reach is also required.
Finally, the interior layout determines how accessible the collection stays. Drawers make it possible to store loose cigars separately without disturbing the rest of the cabinet; models without drawers lend themselves better to storage in boxes.
5. How temperature and humidity control work
The reference range for storing cigars lies between 65 and 75 percent relative humidity. Within that band the cigar stays supple without mould forming. Below it the tobacco dries out; above it the risk of mould increases.
All electric humidors measure these values with digital hygrometers and thermometers and show them on a display, so reading them requires no opening of the door. Traditional humidors work with a separate hygrometer inside the cabinet, readable only when opened.
Two approaches exist for holding moisture. Systems with a membrane filter take up distilled water through a filter that must be replaced periodically. Alongside these are systems with a copper membrane, as in the Raching MON series, with a surface of 350 cm² releasing water molecules smaller than 0.4 nanometres. The practical difference lies in the evenness of distribution and in maintenance frequency: the most accurate systems stay within about one percent of the set value.
In temperature control, the number of sensors determines accuracy. Simple models measure at one or two points, leaving local differences inside the cabinet unnoticed. The Raching MON series measures at seven points and holds a deviation of at most 0.1 degrees Celsius. The more measuring points, the smaller the chance that part of the cabinet deviates structurally from the setting.
6. What odour and ammonia removal do
Besides temperature and moisture, the air quality inside the cabinet plays a role. Two functions address this.
An odour remover draws foreign smells out of the cabinet. In the Raching MON series this happens with plasma technology: an electric field ionises the air, breaking down odour molecules. This matters because cigars absorb smells from their surroundings; an odour-free cabinet prevents outside aromas settling into the tobacco.
An ammonia remover addresses a smell that comes from within. Ammonia is released during the ageing process of cigars and affects the taste negatively for as long as it lingers in the cabinet. Without this function, periodic airing by opening the door is the usual way to remove it, which disturbs the climate each time.
Beyond that, LED lighting is built into virtually all models. The reason is technical: LED gives off hardly any heat, so lighting does not disturb the temperature control. Lockable doors appear on some models.
7. Maintaining an electric humidor
Maintenance consists of three recurring actions: checking, cleaning and keeping up the humidification system.
Checking means going over the displayed humidity and temperature periodically. An electric humidor corrects by itself, but a systematic deviation points to a problem in the humidification system or in the door seal. Anyone seeing swings that do not settle by themselves can conclude there is something to fix.
Cleaning is necessary because dust and residue accumulate inside over time, which affects the aroma of the cigars. The method: switch off the power, remove all cigars and accessories, and wipe the interior surfaces with a soft cloth and a mild cleaning agent. Aggressive chemicals leave residues that harm the tobacco. On systems with a membrane filter, the water tank in particular needs attention. Let the cabinet dry completely after cleaning before the cigars return, otherwise a moisture spike follows.
The humidification system determines maintenance frequency. With a membrane filter, work is added every quarter: replace the membrane and refresh the distilled water. Systems without a membrane filter have no such interval. Always consult the manual of the model for exact intervals. Replacement filters are under Filters & maintenance; a brief overview of the maintenance itself is in the article about maintaining your humidor.
8. What a sommelier drawer does
A sommelier drawer is a separately climatised compartment within the humidor, intended to prepare a cigar for smoking rather than to store it. The conditions in that drawer therefore deliberately differ from the rest of the cabinet: humidity drops to around 55 to 60 percent and temperature rises to between 20 and 30 degrees Celsius.
The reasoning behind it is that a cigar at storage conditions is relatively moist and cool. A cigar lit at that humidity burns unevenly and draws harder. Laying it drier and warmer for a few hours changes the burning behaviour. This function appears on cabinet models; compact humidors generally have no separate climate zone.
9. In summary
The storage quality of an electric humidor comes down to four technical factors covered in this article:
- The control method. A PID system holds a steadier climate than a P system, and that difference weighs more heavily the longer cigars are stored.
- The number of measuring points. More sensors means less chance that part of the cabinet deviates structurally from the setting.
- The humidification system. This determines both the evenness of moisture distribution and the recurring maintenance.
- The ratio of capacity to storage time. The volume needed follows from annual consumption times ageing period, with headroom as a buffer against swings.
Background on what distinguishes a humidor technically is in the article about a high-quality humidor. An overview of available models and specifications is in the category electric humidors.