I had been looking around at foggers/misters since I went to the Atlanta Botanical Gardens and saw/felt the advantages of adding humidity to the air.
They use a high pressure mist system, though their water particle size is rather large and the plants do get wet from it. Something I did not want.
After reading and looking around for about 6 months I bought a Hydrofogger.
Hydrofogger.Com - Commercial and Industrial Humidifiers - Hydroponics Printing Concrete Tobacco
I just put the larger one in about 4 weeks ago and it is awesome.
The fog has a very small particle size, just as small as natural fog.
The fog is very buoyant and humidifies the air without wetting the plants.
The roots can still absorb the moisture from the air but the plants do not get wet at all.
It will also extend the time between watering since evaporation is reduced.
If you get one, do yourself a favor and get the humidistat as well, that way you set it and not worry.
The hydrofogger is very easy to install, you use a saddle valve and a 1/4 in tubing (like for an ice-maker) to connect to the water supply.
Even though I am down here in Florida (and I have 25' of wet-pad) I was still having problems keeping the humidity up during the day time.
I was seeing new roots drying up as they emerged from the bottom of the plant.
In the few short weeks since installing the fogger, I'm not seeing problems with drying roots anymore and the plant leaves are staying dry.
I have an abundance of deflasked seedlings and they are definitely much, much happier.
Added info:
It is also very quiet, when it comes on it is like a hushing sound...
P.S.
I am not associated with hydrofogger in anyway, I am just really happy with my choice and my plants are too!
I only wish I would have gotten one much sooner... I was just hesitant in buying because there were so many different manufactures and designs and sizes. Some of other companies humidifiers are monstrous in size.
They make two sizes and I ended up getting the larger size and I am glad I did, the smaller one may not have been enough. I also wanted to be able to re-humidify the air quickly after the exhaust fans had run. The larger one is roughly half the size of a five gallon bucket.
Best of luck.
Jim T