Light leakage from airduct

Hi all,

I recently upgraded from cfl to cooltube with 250w HPS. For cooling and odor control, I set up something like this;

Carbon filter ->fan -> flexible alu tube -> cooltube -> flexible alu tube -> exit (outside)

even the flexible tube does 2 90 degree turns, light from outside come through alu tube and get inside from cooltube.

only solution I can find is transporting the fan directly to exit to prevent the leak. but its a small fan and I think its gonna effect the cooling performance.

any ideas?

Fixes:
1. Paint inside of duct at corners flat black.
2. Add insect screen/filter to end of duct outside
3. Move filter to between the light and the exhaust end.

nomofatum said:

Fixes:
1. Paint inside of duct at corners flat black.
2. Add insect screen/filter to end of duct outside
3. Move filter to between the light and the exhaust end.

Click to expand...

In terms of where the duct goes once outside the tent, is it okay to simply run it up the room wall. and have it touch the ceiling?

I figured if heat rises, then anything come out of that will already be at the top of the room, but I'm not sure on that "logic". Thoughts, please.

If you use insulated duct it should fix this?