Air Movement, Temperature, and Humidity
 

I have what I am certain must be a question which requires a bit of a subjective answer. I know that adequate air movement provides oxygen and carbon dioxide for the plants, and that Air movement and humidity work together (higher humidity generally requires more air movement), Air movement can be reduced as the temperature goes down, but not eliminated alltogether, and too much air movement without enough humidity will dry the orchid out, so, how do I find the right combination?

A grower whom I respect very much told me it was simple, just use the " I like it" test. He says, if it feels ok to you on your skin, then, it is probably within an acceptable range for the plant. I am hoping someone here can confirm this "rule of thumb".

Guess I do it diferently. I run two small fans in my grow area 24/7. All year. Moist or dry. My grow area tends to get cold on winter nights so the fans keep things more temperate.

In my orchidarium I run two small 3" fans 24/7 inside the tank and a third one through-wall at night only. I do this to just keep air moving as it reduces instances of mold. I've never heard of the relationship between humidity and air movement.

I also have 2 fans running 24/7. I believe that air movement is very important to the health of your plants. You also do not want to have so much air movement that you blow the plants over. The fans should move the air above and below the plants for good circulation. Here is a sit that talks about air movement. Hope this helps. Epsom Salt

Jayme

I have an 10" Acme tube fan that never shuts off and as Ross stated it keeps the heat out of the peak. I use C02 injection in the mornings year around but I just don't see it jumping the humidity up much maybe from 45 to 50 but at 1600 ppm c02 but it drops back down pretty quick

Another rule of thumb is, if you have air-conditioning or heating on, the air is drier than your orchids like and you will have to provide additional humidity somehow (even a pebble tray helps). Both heating and cooling systems take a lot of water out of the air.

I don't subscribe to the rule of dry air needs higher moisture for orchids. I run two situations. One is a grow window with south-facing glass and exposed to room temps - winter temps are 67 degrees F day and 62 degrees F night. No controls for humidity. I know the humidity can get as low as 30% at night. I also have an orchidarium (the tank) that runs 95%+ humidity day and night. Other than that, the 'chids get what they get and they seem happy with the humidity.