A lot of hobby growers do not take this serious enough… In-situ, orchids are exposed to a constant breeze or good air movement. Poor (or no) air circulation when we grow orchids inside promotes problems such as fungus and rot. Good air circulation is especially important since orchids like to grow in really humid conditions. The more humid it is, the better the air circulation has got to be. Good air movement can also help prevent cold/hot spots between the plants and produces a healthier plant over all – and this is a good thing.
My growing areas
*A lot has happened the past two years… things that has had major consequences on my growing areas. This page will be updated very soon to reflect this.
I use 140mm Fractal computer fans on both sides of every shelf in my growing room and there is one of the same brand but 80mm blowing air into each of my mini green houses when I have the lids on them. These fans are not terribly effective however, but they do the job where I have them now. Each fan is daisy chained to a 12V power supply, about 4-5 fans per unit. These power supplies are adjustable from 3,5–12 volt, so you can easily adjust the fan speed to control the air movement. The fans in the mini-green houses only run at 6 or 9 volt while I run all the other ones at full power 12V.
The Fractal fans are not strong enough for these humid environments. In all the vivariums I have installed 120 mm Scythe Gentle Typhoon fans instead. A gamers delight (apparently), but all I care about is that they realt move air, and they really do! In the cool vivarium I run the most powerful ones they make, 1850 rpm (0.083 A, 28 dBA, 98 m³/h) and they are amazing!! Four at the top and two fans in a home made “box fan” on the bottom. The intermediate and vanda vivariums has the same fans but the 1450 rpm models, two fans per case, which is plenty for the space. In the intermediate vivarium I even have them dialed down to run at 9 volt. Each fan is daisy chained to a 12V power supply, about 3-6 fans per unit.
The cool vivarium also get fresh air through a duct fan hooked up to a vent pulling air from the outside for the purpose of cooling the space.