Fan left on at night?

[whygreenberg]

Originally Posted by boytjie

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?

No stupid questions at all. Look at all the great responses! This is an issue I have mulled over myself before. I made the decision to only run my fan when the light is on because I tried doing it 24/7 and found that it dried out a lot of my orchids too much overnight.

[snow]

i have 3 10'' fans running 24/7.
one onthe floor, one mid greenhouse level; and one high up in the rafters.

[Undergrounder]

i have one little fan in an aquarium and i turn it on for 15 mins of every hour, and at night, for 15 mins every 2 hours. I have no idea if this is good or not

[Ray]

Fans blowing on plants do not cool them appreciably, unless they are wet and the evaporation rate increases with the air movement.

The idea of using fans is to provide a small degree of rolling, tumbling air movement to stir things up and help create a buoyant, dynamic atmosphere around the plants, instead of a stagnant one. Doing so keeps the air chemistry stable and helps prevent bacteria and mold spores from settling, and if there are pockets of wetness in leaf axis, helps dry them out.

This is definitely not a case of "more is better" though - gales are to be avoided. Think more in terms of a gently, springtime breeze.

[cirillonb]

perhaps others like me that grow indoors, even in an apartment are concerned about noise. I suggest to test the fan at the retailer and try to determine if you would be disturbed by it running at a low speed(all that is needed for a windowsill grower.) These are not the cheapest fans. The other concern might be energy consumption. That can be figured from the wattage of the unit.
As far as noise in concerned, some people use fans just for the noise (white noise) as it blocks out ambient noises and they believe helps them sleep better (my adult son for one.)
Nick

[Ed b]

I'm in Montana and grow under lights and I keep a fan going 24/7
Ed b

[SP2340]

I think leaving a fan one all night is a good idea. Breezes in orchids natural habitat don't stop at night so why should yours? And you also help eliminate stagnant air.

[Ray]

Concerning noise, if your growing area is relatively confined, the computer-type "muffin" fans are a good choice. Radio Shack even has 120V versions so you don't need a transformer.