Hi folks,
This is a quick demonstration of how to knock up a basic light baffle to allow air intake into your growroom. Excuse the graphics, I did it in a hurry. I made this one out of thick cardboard but when I've got time I'm going to replicate it with wood.

A : First cut a rectangle out of the bottom of your door, leaving enough space either side to give strength to the door. The area of the rectangle should be approximately 5 X the area of your fan exhaust.

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B : Add 3 rectangular sides in the positions shown to form the outlines of a box. The width 'X' should be twice the distsnce 'Z'. The length 'Y' is arbitrary but about 3 or 4 times 'X' should be sufficient. Because I used cardboard, I just connected everything with opaque sticky tape. On the wooden version I'll use them triangular connector thingys or maybe just screw/nail them together.

[attachmentid=29557]

C : Complete the box by putting on a bottom panel. This would be a good time to start painting the inside with black matt paint. You can get a small tin for about a quid from the DIY shop. Remember to paint as you go along, because you can't do it once the box is assembled!

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D : Place the middle panel in the box and secure in place with some pins or small nails in the positions indicated by the arrows.Then seal around the edge with tape. The gap at the top should be the same size as the hole in the door.

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E : Finally, connect the front panel as shown.

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F : When complete, your extraction fan will draw air into the growroom in the manner shown by the arrows.

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Hope this will be of some use to you,
Cheers,
- Lucid.

nicely done m8

should help a few peeps out

excellent diagrams too, it's hard to tell people how a light baffle is put together

Fair Play Lucid, like your style

excellent post,,,

the jigsaw comes out play tomorrow..he he he he

Cheers Lucid M8

Im just in the process of putting all the bits together for me growdrobe and this will be really helpful.

emdeema

Thanks Lucid - just completed a simular baffle only horizontal as the drobe base is raised 3" ie on legs and I've cut a 5 x extraction fan hole in it. This means my drobe space isn't compromised except in height which is another bridge to cross no doubt later

So, dyou mean the baffle is under the drobe? ie. on the floor?
Im just interested cos I have done something similar.

Nice one Lucid nicley done

Remember to Paint the inside matt black too also a piece of black cooker hood filter on the outside (and the inside as well if your fan will take it) stops big nasties and dust getting as well as direct sunlight

Thank you sir, I never understood how those things work until now. Thank you for that, very informative for a nub like myself. Great post. I give it a 10.

Scuse my dopiness but with this system set up are you just using an extractor fan with no intake fan ? I>E the extractor fan expels air at the same time it is drawing air in through the baffle ? Where do you mount the extractor fan ?

i can answer that herbert, you can put the extractor anywhere, but air is best extracted from the top of the growbox because hot air rises and its generally hot air we would like to get rid of.

i made a similar baffle using that light proof sheeting stuck to a wood frame and it too works a treat.

top post lucid mate

thanks for the tip just added them to my room works a treat

My maths seems to have gone down the pan since I left school all those years ago.

If I have a 4" 100CFM fan my baffle dimensions should be ...

7.93" y
2.27" x
1.13" z

Is that right?

If I'm going to have 2 passive intakes at the bottom of my cupboard should I half those dimensions ?

IF My calculations are correct here's an excel sheet calculator for the rest of you folks just add in your fan diameter and it'll do the rest based on Lucids dimensions

http://www.freefileupload.net/file.php?fil..._calculator.rar

very cool ur savin me more and thats what i like to hear likin the explanations i'd be completely lost without ur diagrams too

Has anybody calculated how much these light baffles stop airflow?

I know that each right hand bend in ducting reduces the volume of air by 50%. So does a light baffle with 4 right angle changes in direction reduce the volume of air extracted by nearly 94%?

is this the only way to do this does it reduce airflow?

The larger you made it, the less it would reduce airflow. However if your worried about airflow you may need to have more powerful extraction or use an active intake (eg. a pc inside the light baffle)

Does anyone have the calculator from spobart knocking around my head is struggling with the maths ? thanks
Dak

I ve just been told i need one of these, Great easy to follow, easy to make, does it matter about depth of the baffle?? as space is tight...

Wouldn't it be better to just rig up an S-shape piece of ducting as your intake? That would prevent any light from entering your grow room, would it not? Excuse my ignorance as I'm entirely uneducated in this sort of thing. Thanks for the info.

If you use an intake fan then all you need is a duct hole but a passive intake needs to be at least 4-5 times the volume of the outtake, so you need a bigger area to allow for resistance.