Light Proofing Door Ideas

RuggedWombat

Well-Known Member
I'm having an issue with light pollution currently. Long story short, the grow room has a single standard bedroom door where light pollution is inevitable under the door. I need a way to block the light while still allowing air from the exhaust to exit the room. Cutting the door/wall is not an option.

My first thought was just put a towel under the door, but I worry about fresh air circulation in the room and possibly temps with the lights off. Currently, I lean a piece of cardboard against the door with a cutout at the bottom for the exhaust hose to push air under the door. However, light still leaks from the sides and is bright enough to read a book in the dark.

Does anyone have any ideas on light proofing while not sacrificing air flow? Is air quality even a realistic concern in a 2x4 tent with no supplemental C02? I suppose I could attach a towel or something to the sides of the piece of cardboard to cover the sides as well, but surely someone here can Macgyver something better than I can come up with.

Final note: I need to be able to exit through said door before the lights go out, so it has to be something I can either set up as I close the door or from the other side when it's closed.
 

Absorber

Well-Known Member
I'm having an issue with light pollution currently. Long story short, the grow room has a single standard bedroom door where light pollution is inevitable under the door. I need a way to block the light while still allowing air from the exhaust to exit the room. Cutting the door/wall is not an option.

My first thought was just put a towel under the door, but I worry about fresh air circulation in the room and possibly temps with the lights off. Currently, I lean a piece of cardboard against the door with a cutout at the bottom for the exhaust hose to push air under the door. However, light still leaks from the sides and is bright enough to read a book in the dark.

Does anyone have any ideas on light proofing while not sacrificing air flow? Is air quality even a realistic concern in a 2x4 tent with no supplemental C02? I suppose I could attach a towel or something to the sides of the piece of cardboard to cover the sides as well, but surely someone here can Macgyver something better than I can come up with.

Final note: I need to be able to exit through said door before the lights go out, so it has to be something I can either set up as I close the door or from the other side when it's closed.
Buy a grow tent for the room it will be easier than farting around ;)
 

HandyGringo

Well-Known Member
Agree with buying a grow tent. Or buy a light-proof ventilation baffle thing install it on your door and then lightproof the bottom.


Or buy some regular flat plastic ones from Home Depot or whatever, cut a hole in the door, and have a baffle on each side of the hole, one pointing up and one pointing down, which should block most light while still allowing air to enter

Something like this

images.jpg
 

RuggedWombat

Well-Known Member
I appreciate the feedback, but I think y'all are missing a couple of caveats. I already have a grow tent in this bedroom. It's a 2x4x5. I also absolutely cannot cut through the door or wall to install anything. What I have to work with is the crack under the door. Best options are either seal the crack all together and hope lack of being able to exhaust the tents air doesn't hurt the plant, or allow the exhaust under the door and find a way to seal the remainder of the door crack, but in a way where the door is still operable. The solution would need to be removable as well as during the day I need the entire length of the crack under the door to exhaust as much air as possible. I suppose another option would be place a furnace filter over the tent vent flap so air can still flow through, but light will be reduced.
 

Billy the Mountain

Well-Known Member
I appreciate the feedback, but I think y'all are missing a couple of caveats. I already have a grow tent in this bedroom. It's a 2x4x5. I also absolutely cannot cut through the door or wall to install anything. What I have to work with is the crack under the door. Best options are either seal the crack all together and hope lack of being able to exhaust the tents air doesn't hurt the plant, or allow the exhaust under the door and find a way to seal the remainder of the door crack, but in a way where the door is still operable. The solution would need to be removable as well as during the day I need the entire length of the crack under the door to exhaust as much air as possible. I suppose another option would be place a furnace filter over the tent vent flap so air can still flow through, but light will be reduced.
It most certainly will.

I don't know your configuration, but it's hard to imagine that light from a door gap will cause light pollution to the tent inside. The tent has a a zippered door? What's the concern?

Maybe I'm overlooking something obvious, but the only real problem is blocking all fresh air access.
 

coreywebster

Well-Known Member
Agree , light under a door isn't going to do anything, unless the issue is light from in the room coming out into the hall?

Anyway, just Google light baffle or light trap.
Then construct something that you can tape to the door .

Though I don't think it's necessary.

I have open vents on my veg tents and my flower tents in same room don't care..

But if you really want to the a light trap is the way
 

Fladawg01

Member
Get a door insulator for the bottom of the door on the side you open it from. Once you leave the room after lights out, you put it down across the bottom. They are made to prevent drafts and cold air in the winter for many, but in your case use it to prevent light and still allows you entry and exit as well as light blocking. Find plenty on Amazon.
Maybe this:
MAXTID Under Door Draft Blocker Black Door Draft Stopper 38" Noise Reducer Breeze Light Cold Air Guard Sound Proof Door Sweep 32" 36" 38" Weather Stripping Door Bottom Seal Insulation Strip Gap Filler
 

RuggedWombat

Well-Known Member
Appreciate the responses. Correct me if I'm wrong, but I thought the general rule of thumb which is also recommended by Dr. Bugbee is if you can read normal print in a book, the light is sufficient to stress photoperiod. I agree the best bet is probably just to light proof the tent and see how many layers of furnace filter would be required to block the light.
 

tstick

Well-Known Member
I took a cardboard box that was long enough to cover the span of the door, cut a slot lengthwise along the lower edge of the box that corresponds to the space under the door, and I ran my 6" flexible exhaust duct into a hole that I cut into the top of the box to accommodate the duct...

image-1056636.png

I attached a couple "pull tabs" on the lower edge so that I can pull the box snug up tight against the door, from the outside, as I close the door and this effectively blocks any light while still allowing the exhaust air to exit under the door. Sorry about the primitive sketch!
 

Greengrouch

Well-Known Member
Just keep your tent doors closed lol. My tents in my dining area in my one bedroom apartment and it’s not given me any problems. Active air in take with a fan and filter box in a bottom port instead of keeping the mesh flaps open and a black trash bag tied around the other bottom port my hydro plumbing goes through.
 

RuggedWombat

Well-Known Member
Doesn't the tent have a door that zips close?
I'm having a hard time visualizing how light coming under a bedroom door could possibly cause an issue inside a closed tent.
So the light comes in under the door and casts across the floor of the room with the grow tent. If I put a book next to the only open air vent on the lower part of the grow tent, it's enough light to read the book. From my understanding, this is considered "too much light." This isn't a plug in light or something intensity; these are regular ceiling hallway lights etc. that other occupants aren't doing a good job of turning off on a routine basis. Maybe I should just put a furnace filter on it and call it a day.
 

Billy the Mountain

Well-Known Member
So the light comes in under the door and casts across the floor of the room with the grow tent. If I put a book next to the only open air vent on the lower part of the grow tent, it's enough light to read the book. From my understanding, this is considered "too much light." This isn't a plug in light or something intensity; these are regular ceiling hallway lights etc. that other occupants aren't doing a good job of turning off on a routine basis. Maybe I should just put a furnace filter on it and call it a day.
Try to read the book inside the tent, I think your fear will be assuaged.
 

coreywebster

Well-Known Member
So the light comes in under the door and casts across the floor of the room with the grow tent. If I put a book next to the only open air vent on the lower part of the grow tent, it's enough light to read the book. From my understanding, this is considered "too much light." This isn't a plug in light or something intensity; these are regular ceiling hallway lights etc. that other occupants aren't doing a good job of turning off on a routine basis. Maybe I should just put a furnace filter on it and call it a day.
It's nonsense.

Photons travel in straight lines. The amount of photons making it through that gap at the correct angle is miniscule.

But if you want peace of mind the solution is a long cardboard box the width of a door with a slit on the lower part (door side) and a slit on the higher bit (furthest from door) with two pieces of card at angles that bounce light back , all in black. That allows the same air without the light.

Unfortunately googling "light baffle" no longer brings up these images.
But imagine the opposite of a periscope . Instead of the most reflective surface, your using the least reflective and instead of angles designed to point at each other, they're designed to point back and thus not reflect light or allow it through.
 

nxsov180db

Well-Known Member
I had a grow going earlier this year where I had left one of my under canopy lights on 24/0 halfway through bloom, I had plugged it into the wrong cord, nothing really happened except a few buds showed some signs of a re-veg. but only on that particular plant that the under canopy lights were on. I would certainly imagine my room was brighter than yours was..
 

Drop That Sound

Well-Known Member
Just lightproof the tents intake vents? Easy as taping a 90 degree (or whatever config works best) HVAC register duct vent fitting over the square intake ports, and then adding a few feet of flexible ducting to it. 4-6ft should do it. Mount the flexible or semi rigid ducting in an S curve shape so it traps most the light from coming in the tent. Even if the inside is shiny, it should work ok as is.. although spray painting the insides black will achieve closer to 100% filtration.

1728696268626.jpeg1728696434188.png
 

Absorber

Well-Known Member
So the light comes in under the door and casts across the floor of the room with the grow tent. If I put a book next to the only open air vent on the lower part of the grow tent, it's enough light to read the book. From my understanding, this is considered "too much light." This isn't a plug in light or something intensity; these are regular ceiling hallway lights etc. that other occupants aren't doing a good job of turning off on a routine basis. Maybe I should just put a furnace filter on it and call it a day.
Get a 90mm storm water bend and short bit of 90mm pipe spray inside with black spray paint and fit that on the outside of the tent intake .
Problem solved
 

nxsov180db

Well-Known Member
So the light comes in under the door and casts across the floor of the room with the grow tent. If I put a book next to the only open air vent on the lower part of the grow tent, it's enough light to read the book. From my understanding, this is considered "too much light." This isn't a plug in light or something intensity; these are regular ceiling hallway lights etc. that other occupants aren't doing a good job of turning off on a routine basis. Maybe I should just put a furnace filter on it and call it a day.
It seems impossible to me that light coming through the door would be enough to also go through an air intake/exhaust opening in your tent and cause an issue. I guarantee you won't have a problem. The outdoors at night is not completely black.
 
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