Lights out exhaust?

How important is lights out ventilation? My "room" is outside(its a cellar) so air is very cold. It's been between 10-32degrees lately and I quit exhausting at lights out or it will lower my temps down in the low 60's I have a heater for lights out but it can't keep up. So how important is it really to exhaust at night?

Monitor humidity. If not spiking above 55% when dark I wouldn't vent.

if your rh is perfect and your temps r where u want them, then I'm going to say its not important at all. the only time my room exhaust when lights out is if the temps get to high.

? if u are running a system with venting on the lights in a cold area why not rig the system up so the hot air from the light is blown down (take the ducting and vent it down on one coner of the room to raise the temp)

u still need the exhust and intake for the fresh air for the system...........lower the exhust rate the temp in the room will increase ......when the intake air warms up u can stop blowing it down


ohhhh or better yet reverse the system .........just make sure u use a filter system for the intake u do not want hugely wet cold air passing over a hot light..........this would warm the cold air up fairly well ...........u will just need to have a high exhust point and close off the old intakes

I run bare bulb vertical. I have a 1000 and a 600 its a stadium deal w/ a couple fans blowing around. I know everyone will say i'm crazy but i have both lights about 4-6inches from some buds(they grew bigger than i intended) check out my sig its my current grow. I think my humidity is getting over 55. I do have a demudifier but havent been using it since i got this exhaust(first 3 runs w/o filtering crazy i know, just used a/c to move some air) I will monitor it the next few days and see where i'm at. I'm run MNS critical mass and i really need to pay attention to humidty more, i'm in week 4 of flower and they are already as plump as my bubba and master kush after 8 weeks. Appreciate everyones responses.

I guess I was unsure if not having fresh air during lights out was kosher or not.

powerslide said:

I guess I was unsure if not having fresh air during lights out was kosher or not.

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It's not like you need fresh co2 laiden air when lights are off. What you should definitely be worried about is keeping that humidity in check, as Snaps said above, keep it under 55. I would put your ventilation system on a day/night temperature switch. Set the dehu to 40. This will really help with cold months or cold climates, when dark.

While the ventilation is off, the dehu(if properly sized)will keep humidity low, while making HEAT. When/If it gets too warm, the ventilation kicks on to drop down heat. Ya dig?

Of course, this will not work if you are only growing in a small part of an open, huge cellar. Your going to have to build some walls or insulate or something, to be able to contain heat.

Its actually a storm cellar detached from my house. Its easier to keep warm than a big open space would be. Its roughly 10x8x7 The top foot is uncovered to the elements and it has two vents. I turned the demumid on last night after posting this and set it on 60. I have a couple electric thermo/humidty deals around the space and they ranged from 40-70. I need to get some new ones they are old and been wet a time or two. But at the time i looked at them they said about 45% and the dehumid said it was 60. So i just left it set on 60 and will check them all tonight. I just know i'm pretty close to the max on the breaker so i was trying to keep from running the dehumid. I dont know how to wire the exhaust fan so it comes on at a certain temp.

Use a line voltage thermostat on your fan.

A cooling model is what you need.

As far as available power/load: Put the dehu on a timer opposite the lights. The dehu has to have an auto-restart ability. Most NEW digital ones do these days, but make sure first, for it to power on/off via timer.

If you don't want to mess with wiring a line voltage thermostat, heres a good plug in thermostat for ur fan.
http://www.hydrofarm.com/product.php?itemid=13337
Peace