How do you raise and lower duct connected to air cooled hoods?

[weimer222]

I plan on running duct through my air cooled lights, drawing cold air outside, through the lights, and then exhausted back outside. No exposure to the grow room air.

I am trying to think through the set-up and am wondering how people deal with the flexible duct as you raise the lights over the grow period. The duct (at least the sections going into the first hood and leaving the last hood) will be long when the lights are low to accommodate early growth. Later in flowering, the lights will be higher. If I keep the same length of duct that is needed when the lights are lower, it will seem to created a u-shape when it gets higher, thus reducing air flow.

Is that just the way it is or is there someway to address this issue? I thought about having different lengths of duct I could attach at different points of the grow to keep the duct line as smooth and as straight as possible. However, that seems like a pain in the ass to have to keep reattaching different lengths of duct as you move the lights up.

How are others dealing with this issue?

 

[Giant]

I plan on running duct through my air cooled lights, drawing cold air outside, through the lights, and then exhausted back outside. No exposure to the grow room air.

I am trying to think through the set-up and am wondering how people deal with the flexible duct as you raise the lights over the grow period. The duct (at least the sections going into the first hood and leaving the last hood) will be long when the lights are low to accommodate early growth. Later in flowering, the lights will be higher. If I keep the same length of duct that is needed when the lights are lower, it will seem to created a u-shape when it gets higher, thus reducing air flow.

Is that just the way it is or is there someway to address this issue? I thought about having different lengths of duct I could attach at different points of the grow to keep the duct line as smooth and as straight as possible. However, that seems like a pain in the ass to have to keep reattaching different lengths of duct as you move the lights up.

How are others dealing with this issue?

I just make my ducts long enough to reach in the early stages, and as it gets higher I just coil and bunch the ducting up to level it off. Sometimes I need some zip ties to keep it together, but it works. I havent noticed a reduction in air flow in any case..

 

[Bud Spleefman]

For me there isn't that much variable between lowest height and highest... I use the softer flexi duct and at the lowest it's like 3 ft off the tops of the buckets and the highest, maybe 5...... if you use a really strong fan it won't matter much. I use a Vortex 8 cooling three radiant 8's and they run pretty cool... I could probably cool 4 hoods.... but my outside temps are pretty cool, too... it will also depend on the temp where YOU are growing.
Also, I don't rasie the duct, I raise the hoods.. the duct is attached, so it comes with it....
Here are some pictures, hope this helps!

 

[Graham Purwatt]

yeah,if you have enough airflow then the flex ducting kind of accordions,you move the hood up,it sucks in the slack ducting.i always setup with enough ducting to reach the lowest possible point that the light will hang and have yet to have a loss of flow or to have to bother with excess ducting.hope that helps bro

 

[Lazyman]

I don't often need to move my hoods, since young plants don't need super bright light I keep the hoods higher and let them grow towards it. Works quite well, but I use string hung from the ceiling to hold up any extra slack. In general you should remove as much slack as you can though, keep your canopy even (pruning and strain selection) and keep the lights even.