I am not a smoker, thank goodness I never went down that road, but I know a lot of people who are, but one of my best friends, a guy I have known since all of us were in grade college together, is a cigar buff.
Personally I guess cigars smell great, until you light one up, then it smells love burning creature hair, recently my pal wanted to take his care about of cigars to the next level, and started toiling on a walk-in humidor for his house.
Basically a humidor is supposed to maintain the perfect level of humidity for maintaining the best tobacco. A walk in humidor would need a little Heating and A/C labor as well, to make sure the ventilation system was toiling well, and to keep the room pressurized, but since the door would open once in a while, he wanted to use the central Heating and A/C system to create higher pressure inside the humidor. That way when the door opened the air would flow out, but not in, and all the air in the room would maintain the perfect humidity levels. All of us hastily found out that this was not something his central Heating and A/C system could handle on its own, so all of us needed to do some building and renovating. I recommended putting a dehumidifier in the room instead, as it would be much easier, however he informed me that having too little humidity is as bad as having too much, so a dehumidifier would not work. It took some consulting with experts, but finally all of us got the humidity and ventilation problems all settled.