Fan left on at night?
 

Okay... going on the brave assumption that there are no stupid questions, here's one: I have a fan set on a timer to switch on and off with the T5 lights on my growing shelf. Now, though, I'm starting to wonder if the fan should just be left to run all the time, day and night? What do you other folks do? :scratchhead:

I have several fans. Some run 24/7 and some run with the lights. Here is my set up
http://www.orchidboard.com/community...bs/DSC2677.jpg http://www.orchidboard.com/community...bs/DSC2546.jpg

The tank has one fan 24/7 and a second running through-wall for 3 hours at night. As you can see in the second photo, the topmost fan runs 24/7 and the fan at right runs when the lights are on. So, in answer to your question, set at least one fan to run with the lights. If you have more than one small fan, feel free to keep one running 24/7.

Okay... that sorta answered my question, or maybe I'm just being dense: I only have one fan. Off at night, or 24/7?:dunno:

It's safe to run it 24/7.

I don't think you will find an unified response...I have never seen one. My small layout has one fan hooked to a timer and the other on 24/7. Interestingly, the only group that get minor mold spots are under 24/7 fans. That being said, I have the house's A/C fan on 24/7 (cold air directed away from orchids) but that give a "buoyant" airflow throughout the apartment.
Nick

If it goes anything about 75 degrees then I fan at night, just for my phrags.

I keep my fans on all the time. . .24/7.

My one fan in my one little tank is on all the time.

I would agree that there probably isn't a single correct answer and that each growing situation demands specific requirements. I grow in a GH. I have a main exhaust fan on a thermostat set to 75 deg. and the theromstat has a +/- 2.5 deg range. I also run a large 21" fan 24/7 low at night and higher during the heat of the day. I like to circulate air in the GH because I believe this is one way to help combat crown rot in phals and keep things cool through evaporative cooling. I really don't know if all of this is scientific but so far it's working for me.

I also grow in a greenhouse and have pretty much the same setup as Doc and I run at least one fan 24/7. If the night time temps are staying high in summer and the humidity is also high, I run 2 fans 24/7.