Although air movement is very beneficial for our plants, there also negative effects of too much air movement especially with your more mature plants. If leaf surfaces are cooled too much, your plants leaves can literally curl up. This unfortunately reduces the amount of active photosynthetic material on the leaves. Extensive strong air movement can cause your plants leaves stomata’s to close up, as your plants will try to alleviate any water loss, thus ultimately this process will stop the exchange of oxygen and carbon dioxide, leading to reduced or stopped photosynthesis.
Am I the only one that didn’t know this?! Argh. Well. Definitely room for improvement on the next grow!
I don’t think it’s news that you can have wind damage without broken stems and such. But I definitely wouldn’t have been able to give a supporting explanation like that.
You just want to see a light wiggle among your canopy when air moves by. I believe oscillating fans help with this too. As even if it’s a little strong, it’s not constant.
Well that’s the thing my tent isnt a wind tunnel. Hell all I have in the tent for moving air is a small 6” clip on fan. It’s the high rate of intake and exhaust that might be causing my clawing. It’s not like I can even feel a breeze in my tent.
Yeah I understand I can’t have a strong dan blowing directly on the plant. I’m more interested in having too much intake and exhaust.
I like your idea of an interval timer and I plan to copy you. I’m mostly hoping to preserve some of the heat I’m adding to the tent with my space heater. It seems counterintuitive to heat the space and then just exhaust it out, at least from an efficiency perspective.
My tent is in an uninsulated garden shed so any heat that is exhausted just dissipates.
If I ran same intake in winter as I do in summer I would have dead plants in couple of hours during dark cycle minutes during summer I have holes in floor for passive intake. Winter I fill them with expanding foam and blend air in my main work space outside growing space which has slightly less insulation than my main grow space with r-36 ceiling r-24 walls r-5 floors work space only has r12 in walls rest is the same biggest heat loss is dog door Front door still needs to be replaced in future but is doing the trick for now
@Bogleg, I did a little experiment today while waiting on my interval timer (due to arrive tomorrow or Tuesday). I manually switched my fan on and off from outside of the tent (ran the extension cord out of the tent and through a switched outlet) and measured energy usage over the course of that hour and the hours adjacent to it. My switching was irregular since it was manual, but I tried to approximate about 1/4 time on - that is, 15 minutes out of the hour in one- to two-minute intervals. The results are pretty encouraging. Remember that these include my LED panel light, heater, and exhaust fan. So turning the fan off will not only reduce the need for heat but will by itself stop using electricity.
Previous hour: 0.945kWh used
Sample hour: 0.429kWh used
Following hour: 0.956kWh used
So in my test case, I used less than half of the electricity that I’d used in the adjacent hours. Not terribly scientific, but encouraging nonetheless.
@Covertgrower has it right. I was only cycling my exhaust fan. The idea is to cut down on heat losses in the tent when I’m running a space heater. I believe @Bogleg is shooting for a similar outcome. Less energy waste, but still adequate airflow.
Interesting. I got my timer today and just installed it. After 5 cycles (15 minutes) the tent is at 75F. I turned the heater down and will check it right before lights out and then again an hour after lights out.
I checked the tent right before lights out. Temperature was holding steady at 77F and the humidity was at 35% - again the mister is not on in my tent currently.
I then checked my tent 30 minutes after lights out and the temp was 57F with humidity 41%.
RH in the basement right now where the tent is was at 51%. Not sure of ambient temp in the basement, but probably around 57F. I will check one of the hygrometers I have in my jars… didn’t think to do that. I will check them one more time before I go to bed to see make sure everything is okay atmosphere-wise.
Oops…temp is down to 46F. I turned the heater back up to it’s highest setting. I am leaving on a work trip tomorrow until Tuesday night so I might have to just put the fans back to always on and run these tests again.
Front door still needs to be replaced in future but is doing the trick for now