Let me I've you a little run down about my setup I'm attempting. I Live in Alaska and This will be me and my wife's first grow. I have built a 10x8 fully insulated, heated, wired grow room behind my house. And I have come to planning the ventilation setup and can't quite figure out the best way. I was going to grab outside air through a phresh intake filter setup and exhaust through a Carbon filter. I have 2 600w lights with air cooled hoods and planned on ducting outside air in then and exhausting outside creating a separate ducting system for my lights reducing the need to filter for odor. My MAJOR concern is intaking air temp down to 0 or more and running it to the lights. I believe that condensation will be a big issue. So I have thought of other options such as intaking and exhausting air in the room already, then only have an exhaust setup with a passive air intake? I don't believe that heat will be a major issue as I can exhaust faster bringing more cold air in the passive intake. I would prefer to stay with my original plan with a separate system for the lights. Has anyone had experience intaking cold air and removing or avoiding condensation? Sorry for the long write up just want to give you all the info. Thanks
You're better off using room air for intake then outside unless your room air can't cool down the space enough. It's dryer and more optimal temp.
I use cold air from outside for my cool tube reflectors and exhaust to the outside during warm weather. In the winter I undo the ducts so the hot air from the lights helps warm my rooms. I used insulated ducting for the light cooling system and have no probs with condensation even tho I live in a very humid area. I then use separate 12" fans and ducting to exhaust hot air out of the rooms at ceiling level and have passive intakes at floor level with furnace filters over them
I also live in a very cold climate (not quite as cold as yours), but I deal with lots of cold weather issues. I am afraid to hook my air-cooled hood directly outdoors, I'm worried it could crack the light due to extreme temperature difference. Also, sometimes I struggle with temperature gradient in the room. My canopy will be a nice 75F, but my floor will be at 55F!! the roots do not like that
I had major issues with condensation pulling -20 deg f air thru lights then back outside even well insulted ducting eventually molded, i rerouted intake from an adjoining room which helped alot the other siggestion is to insulte the floor i was getting condensation where the floor meets the walls.. also directing the light heated air back into the adjoing room was also a failure due to high humidity... hope i helped thank goodness only got to 23deg f last night winter is over
Hey, I've been afraid to pull really cold air over my light, because I've been worried about cracking the light. It sounds like you've never had issues with light cracking due to temperature difference?
Camp: no i never did have a bulb pop due to cold temps but due to the heavy moisture build up on the ducting i did not operate that way long, the ridged insulated pipe was literally dripping water, i also was switching to a double ended bulb set up and they say bulb efficiency suffers with to much cooling... i tried taking air from underneath the floor it was a little better but not acceptable.., there maybe a solution but i gave up early...
This is the insulated ducting I am using. I have never had condensation issues even tho I live in a rain forest (Vancouver Island) We don't experience cold temps like u do nbh, it rarely goes below freezing here. High humidity very often tho.
I have what looks exactly like your ducting first try was slipping insulation & cover off flex tubing then slipping it over ridged galvanized i had but then thought maybe the metal was causing more moisture since it conducted heat & cold more then the flexable so i switched and it did have less but was still dripping right at the wall where the temp differances was the greatest i think one could mess around with packing the ducting into another larger insulated pipe and maybe reduce the issue but i did not have the time or space available at the time
During high relative humidity periods my metal flexible ducting used for room ventilation does sweat some. However the insulated ducting which is plastic inner and outer sandwiching the Fiberglas insulation never sweats
I have to run humidifiers we rarely get above 30% naturally from what i read high humidity can be a pain to deal with so i guess i am lucky when it is those last 4 weeks of flower and drying? I used to get nose bleeds from the dry summer air... more snow forecast for the weekend here sucks!,
Are you pumping the heat from your lights into your living area? I don't understand why you need to run air cooled hoods in winter temps, especially in a separate building. I take full advantage of winter temps, dismantle the light ducts, remove lenses, and put it back together for the 3 or 4 months a year when it's needed. Is there something about extreme temps that you guys are using air cooled hoods? I fucking love growing open hood in winter.
I tried to use it to subsidise heat in lung room i tried with and without glass, unhooked ducting etc. All ended up causing humidity problems in adjoining room once flowering was well underway, i hooked exhaust back up and sent it outside and used passive airvents from semi heated lung room, i am well insulated but -20 deg f for weeks was a bitch, only time heater runs in grow room is during lights out i do use heat from DE bulbs lights but room will exceed 90 deg f if i do not get rid of excess heat...