Tobacconist University
Get Certified    |    Campus Store    |    R&D Lab    |    FAQs

Sunday, November 11, 2007

Building A Walk-In Humidor

Building a Walk-In Humidor is the kind of project that seems a lot easier to do than it really is. A Walk-In Humidor must be able to maintain precise Temperature and Humidity regardless of the outdoor climate: it is like creating a self-contained ecosystem in your home or work.

While craftsmanship and aesthetics will vary, there are a few important issues to keep in mind.
· Locate the Walk-In on the interior of the house/building to avoid temperature variations created by the sun and season.
· Always acclimate the wood for a minimum of 72 hours to 70% RH. All wood will expand in high humidity.
· If you are staining and sealing any of the wood, do it outside of the Humidor so the Spanish Cedar will not absorb the chemical aromas.
· Use all-weather nails and screws that will not rust or bleed onto the wood.
· Make sure all electrical outlets and machines are grounded and use surge protectors.
· Use a plastic vapor barrier between your interior walls and the humidor lining material (Spanish Cedar).
· Insulate the Humidor as much as possible to preserve your temperature and humidity.
· If you are using drywall as a substrate, use the mold resistant variety.
· Always wear safety goggles and a mask when cutting or sanding wood!
Any discussion of Humidors would not be complete without mentioning and understanding Spanish Cedar. Spanish Cedar is a hard wood that easily absorbs humidity and releases a mild, spicy aroma for many years. When used in a humidor it should not be finished with lacquer or urethane; the wood should be exposed so it can breathe and release its fragrance, as well as absorb moisture.

Unfortunately, Spanish Cedar is also very expensive so it may not be a prudent expense. Fortunately, it is not necessary to use when constructing a Walk-In. You can use Spanish Cedar as trim or shelving to save money and still get the great aroma it provides.

Take Note: Spanish Cedar produces an extreme amount of dust when cut or sanded so always wear a mask since the dust is extremely carcinogenic. And even worse, the dust will impregnate your system and ruin your taste buds for days.

Cooling & Heating
Maintaining a cool temperature is often the biggest challenge to a Walk-In. Raising the temperature above 72° or 73° F will put your cigars at risk for a Tobacco Beetle infestation. Keep in mind that the ‘hot spot’ in the humidor will be towards the top where hot air and heat from lights will accumulate. If you are building your Walk-In below grade, in a basement or cellar, then you may never have to worry about cooling.

In commercial applications the thermostat for the air conditioner can be located inside the humidor, which makes it relatively simple to control temperature. When this is not possible, it may be necessary to add a small air conditioner to the Walk-In. The size of the air conditioner will vary depending on the room, but there are generally two important issues to consider:

· Disposing of the residual water created by the a/c.

· Evacuating the hot air produced by the a/c.

Most portable and wine cellar air conditioners have a heat vent hose which can be exhausted outside or into an adjacent room (check with specific manufacturers). If you are able to vent outdoors, then this solution should work well for the water which needs to be removed. Otherwise, some portable air-conditioners have water reservoirs which can be manually emptied. In addition, there is technology which mists the excess moisture back into the environment.
If you keep your building at a comfortable temperature it may not be necessary to heat the Humidor; the machinery, humidity, and interior walls may trap enough heat to keep the Walk-In at 70° F during the winter; it is also possible to keep your cigars in the low 60° range and maintain acceptable humidity. If the temperature gets too hot, you may want to have a manually controlled damper/vent or exhaust fan on the ceiling of the humidor which can vent into the attic; this will allow hot air out and cool air in during the winter months. Remember: Heat is the enemy of Cigars.

Humidification & Water

Active Humidifier
Passive Humidifiers, typically used in humidor boxes and cabinets, will not be powerful enough to humidify an entire room so Active Humidification is the best choice. The most common Active Humidifiers have a fan blowing over water and re-directing the moisture into the room. Some units should be positioned high in the room while others work best on the floor while they fan the moisture up (check with your specific manufacturer). Most Humidifiers will have the option of installing a water line or you can simply refill the reservoir when necessary; having a dedicated water line will save time and maintenance work in larger Walk-Ins.

Additionally, a Humidistat should be used in conjunction with the Humidifier to accurately regulate the humidity.

Reverse Osmosis Water Purification
As always, use distilled water and/or invest in a Reverse-Osmosis (RO) water purification system which will pull all of the pollutants and minerals out of the water: make sure to use plastic tubing when using an RO system since the water will eat away at metal plumbing.

  Even with distilled or RO water, it is still important to clean out the humidifiers. Algae can still develop in the water reservoirs so regular maintenance and cleaning will be required. RO water purification systems also require filter/cartridge changes approximately every year.

Lighting can be tricky for two reasons: lights produce heat and the wrong type of bulbs can fade and damage your cigars during prolonged exposure. In addition, Humidor lights should render true color to convey the actual beauty of your cigars. Avoid fluorescent and incandescent lights which distort color. Instead, invest in low Ultra-Violet (UV) and Infra-Red (IR) light bulbs which replicate daylight; the same lights used to illuminate artwork are perfect for cigars.


Allowing fresh air in and out is essential to any Walk-In. Walk-Ins should not be hermetically sealed. They should be able to allow fresh air in and expel hot air when necessary: cigars need fresh oxygen to age properly and avoid moldy conditions. In a commercial environment, fresh air exchange can be facilitated by the frequent opening and closing of the door, but in private Walk-Ins, care must be taken to keep the air circulating.
Walk-In Humidor Ventilation is a subtle process; changing the air in the room about once every day is sufficient. Often, the very small gap around the door is enough to allow air exchange, without significantly hampering the Humidor’s performance. A Walk-In should not have a return duct inside; this would result in humid air being removed too quickly.
If your Walk-In has a supply vent for cooling and heating, this vent should also have a manual damper so you can control the input, depending on the season and your specific needs.


Just like with great cigar making, there are very few hard and fast rules when constructing a Walk-In Humidor. Everything depends on your unique constraints and circumstances: heating, cooling, ventilation, humidification, and resources will be different for everyone. But, the principles and issues articulated here apply to all situations.
Our experience tells us that Temperature is often the most critical issue, and if you are lucky enough to put a Walk-In in a basement or cellar that self-regulates, then you should count your blessings. If you have the resources to provide independent climate control to your Walk-In then you are also in a privileged position. But there are options and solutions for everyone else as well.
Each Walk-In is an experiment that must be well planned and executed. Having multiple thermometers and hygrometers located throughout the Humidor will be necessary to understanding the small ecosystem you have created. If you need to change the system, tweak the variables: move the machinery, adjust the damper, or contact Tobacconist University if you need any help.


  1. hi Guys, i really appreciate all the info you've provided on how to build a walk in humidor. i am starting my which is located in the basement with 4 interior walls and am looking a for a system and have had no luck online. size is 6x8x8ft. i can bring power and drain.
    i am in Toronto Canada and am wondering if you can point me in the right direction.
    regards, Vince DiBattista

  2. Great post . It takes me almost half an hour to read the whole post. Definitely this one of the informative and useful post to me. Thanks for the share.

  3. Thanks for sharing such an informative post.


  5. Thank you U of T! Im a contractor about to install a walk in humidor in a commercial setting. My first. Thanks to you i will now go into it in a more informed way. Thank you!

  6. Can you suggest some companies that would install a large active humidifier? Thanks!

  7. Excellent information much appreciated