First of all i'd like to thank all of those who share their grow experiences on this site. This site has been very resourceful and answered many questions I've had that you can't get answers to elsewhere. Hopefully this post will be of interest....
I've grown orchids for over 20 yrs. I prefer to grow them in clay pots because they cause the growing media to dry out faster than plastic and orchids like their roots to dry out quickly so they can breathe. After reading about fruiting bins and keeping the humidity high in them using foggers, misting a diagonal plate, using vermiculite or perlite in the bottom, etc.....i had this idea come to me (lightbulb right here)....
I made seven 1/2 pint jars of brf cakes per the pf tek. Innoculated with B+ strain. 18 days later cakes ready for their happy birthday. In large plastic bin i placed clay pots upside-down across the bottom. Then poured water in bottom of bin about an inch deep. The cakes are placed on top of the upside down pots, keeping them away from the water in the bottom of the bin. The theory was that the clay pots would absorb water from the bottom and evaporate it out into the air of the bin. Humidity will self-regulate on its own as only so much water can saturate air at a given temperature. I'm not sure what 'size' these pots are, i mean what they are called. They have a 3" diameter at the bottom and 4 5/8" diameter across the top. Plain clay pots. You don't want to use any with glazed surfaces as they are basically sealed and will not absorb and give off water.
If you look at the sides of the bin in this pic you will see the moisture on it. The lid of the bin had a fine mist look to it. There was never large amounts of condensation on the lid that would 'rain' down on the cakes.
In this pic, and also in the one above (upper left cake) you can see how the mycelium grew down the sides of the pot. This did not happen on all pots. I'm guessing there was some sort of food source on the side of this pot, though i cannot imagine what it would have been. I washed all these pots through the dishwasher and then sprayed with H2O2 prior to use. I made sure pots were dry and H2O2 was gone before cakes were placed on them.
At 10 days there were 8 pins. At 12 days, 62 pins. At 14 days, 109 pins and shrooms. 5 to 26 per cake.
There ya have it. I've grown these out two other times with similar results. i never spray these bins or provide any other water besides the 1 in of water that is in the bottom of the bin. I had also hoped that moisture would be wicked up into the cakes themselves and keep them hydrated but i don't believe this actually occurs after taking the cakes apart once spent. The only thing i do with the fruiting bin is fan fresh air in with the lid twice per day. Have not had any issues with contamination of the cakes. I welcome any questions, further ideas along these lines, or other input. Would be interested in hearing if anyone else has any experience with this or something similar. Thanks.