Humidifier vs. fogger

[IowaOrchid]

I am trying to come up with the best way to keep high humidity in a plant shelf that is enclosed. I have a three shelf unit that is enclosed with shower curtain liners and mylar taped to that. I would like to know which would be better a cool mist humidifier or a fogger. I bought a cool mist humidifier but I'm wondering which would be better to reach the upper shelves. All of this is for this winter when my humidifier drops to 30% or less.

Julie

[smartie2000]

fogger increases humidity much faster so I put a fogger inside of an old wick & fan humidifier

[Ray]

In an enclosed volume such as the one you described, either will work just fine - assuming it's reasonably sealed (you do need to allow some air exchange). In fact, as fogger may end up overwhelming the evaporation rate and give you a bunch of wet (and rotting) plants.

Entropy is your friend, so the absolute humidity will be nearly identical throughout. The relative humidity will vary with temperature, so heat stratification will keep the %RH lower up top where it's warmer. A small fan blowing the heat down from the top will remedy that, and good air movement is a real plus anyway..

[IowaOrchid]

Thanks Ray for all that info. I do have a small 5" fan on each shelf. I'm glad you said to blow downward because I have it set up to blow upward. I do have the top adjustable so I can let in more or less air from outside. I think I will just stay with my cool mist humidifier. That way they won't rot on me. Thanks so much for the help.

Julie

[Ray]

I don't think the direction of the fan really matters that much, as long as the flow is sufficient to create a buoyant, turbulent atmosphere that mixes all of the air in the enclosure.

Down is just more common as it gets the fan out from underfoot.

[euplusia]

I made fog experiences in my greenhouse because I thought to copy nature. My observations:
You can mist in the early morning - but not all day long. The plants stayed healthier, when the mist waved upward from the ground. Good ventilation and fresh air is also needed.
Later I climbd Maderas volcano in Nicaragua. There is a constant wet zone lacking orchids at all. Above and below this mist belt there are orchids - where they can dry in between.