In the past few years the components which make up a humidor have become readily available to the woodworking hobbyist. And since a humidor is quite simply a box lined with Spanish cedar and containing a small humidifier, it can be made as simply or elaborately as you wish.
Spanish cedar is the defacto lining for humidors. Its aroma is not overpowering and its ability to absorb and release moisture makes it an excellent choice for maintaining a humid environment.
The humidifier is a small self contained unit which holds distilled water and creates a constant relative humidity of approximately 70%. Different sizes of units are available. The humidifier I use is the Credo Rondo Précision 70. It has the capacity of humidification for 25 to 40 cigars. Unlike other humidifier models, the Rondo does not require refilling with a 50/50 solution of water and propylene glycol.
Refills of distilled water are all that is required. However, every six months it is recommended you regenerate the active substances with the Credo Special Care Solution (propylene glycol).
The instrument used to measure and display relative humidity is the hygrometer. Both mechanical and digital models are available. Although the hygrometer is not required if you fill your humidifier regularly, it does add a certain credence to your humidor.
Another measure of importance is constructing the humidor as airtight as possible. This is done by allowing the lid to overlap the inner Spanish cedar lining. And that's it. From here you can use your imagination to create whatever casework you wish. If you like oak instead of the traditional mahogany, go for it. Use brass hinges and a brass framed hygrometer. Or plywood and black car paint. The sky is the limit, so pull out your designer's pencil, and start sketching. What follows are the basic plans for the humidor I constructed.