intake/ light trap/ sump cooler & sump all in one idea

hey ic magrs!!

after reading one of Aeroheads posts, on his new wine fridge build, i came up with an idea for an intke/ light trap/ sump cooler & sump all in one. i though i would start a thread to get some advice and see what everyone thought before i jump into building it.

alrite it a 2 piece design and would go something like this:

1st the outer shell. figure the desired dimensions. for simplicities sake we will go with Aeroheads dimensions that he mentioned for his build, 18w"x18l"x10t". this would not have a top but just only a bottom and 4 sides. what is needed is a hole for the air intake. for that you would find the center and cut out an 8" hole, which gives you 50 1/4"s of surface area. there will also need to be an 8" hole in the bottom of the cab directly under the 8" hole of the outer shell.

2nd the actual sump itself. the sump will be slightly smaller than the outer shell and will have linear spacers or cooling fins along the outer wall. they should be fabricated to fit snugly into the outer shell. the cooling fins will run up all 4 walls of the sump. there will also need to be spacers that wont restrict airflow on the bottom of the sump to allow air flow.

so here is how i think it will work. the air will enter in via the 8" hole in the bottom of the cab/ outer shell and flow along the bottom of the sump. then flowing up the walls through the cooling fins and out the top into the canopy. my theory is that the air flowing along the bottom and through the cooling fins will cool the sump.

im guesing that the size of the fins and the spaceing has alot to do with how much it will cool. as does the material im sure. would acrylic or stainless steel be better for cooling? i would say that aluminum would be the best bet but IMO it would be too much of a pain to find someone who can weld it and has the equiptment to so. yes there may be the same problem with stainless steel but it will be easier to find someone with the equiptment to weld that before aluminum.

i hope i painted a good enough picture for you to understand exactly what it is that iv got in mind. if anyone has any advice or opinions then please fire away.

o one more thing. Aerohead mentioned it when i brought the idea up was some sort of hepa filter for the intake. definitely need that to keep all the pests out

Hey man I think I understand. Sounds like it would work, I mean, of course it would work. I'm thinking you could use aluminium angle for the fins - aluminium is very good at conducting heat and they make cpu heatsinks fins out of it. You use thermal compound to stick them on, it conducts heat too. I'm not sure how strong it is at adhesion though.

hey ScrubNinja! thanx for stopping in with the advice. i wonder if there is any type of epoxy that would bond aluminum together good enough to keep it from leaking?

well i did some looking around and found this. is there anyone here that has used it before? and if so would it work for bonding aluminum together and keep it water tight? and would it hold permanently?

Well the thing is, you don't ever want to use aluminium in a res or a pot. It reacts with nutes and screws with ph etc. What I had in mind was a stainless (or whatever) res, with the aluminium angles attached outside. I'm thinking a dab of glue on each end to handle the adhesion, then regular thermal compound on the rest that's in contact with the outside of the res, to conduct the heat through to the fins. Hope I haven't misunderstood you and confusing you, haha. Peace.

thanx for that info i had no idea that aluminum would affect those things. would the staiinless cooling fins not work as good as the aluminum?

Glad to help brah. I'm not dead certain on aluminium vs stainless as a heat conductor, but I believe aluminium would win. From the aluminium wiki page:

Aluminium is a good thermal and electrical conductor, by weight better than copper. Aluminium is capable of being a superconductor, with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss.

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I'm not sure about the "by weight" thing. Perhaps copper would be a better choice. But the way I'm picturing it, the aluminium angle is the perfect shape to attach and be a fin.

Edit: Just had a thought. You could assemble various potential materials in say, 3 inch rods, equal thicknesses. Hold them both over a candle and the first one to make you say "ow" is what you should use for your fins.

Editedit!: Wait check this out From the "applications" section of copper's wiki page:

As a material in the manufacture of computer heat sinks, as a result of its superior heat dissipation capacity to aluminium.

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I thought they were aluminium? But there you go.

Hey by the way, I have no idea that stainless is actually ok to make the res out of either. I think Aerohead said it's ok though if I remember right? So if he said it's good to use, it's good to use.

thanx again man il try the candle test to see which one is the best. im going to try acrylic also to see how that goes. unforunately i dont have the time to fab up a stainless steel sump, nor do i have the means to weld it together. im hopeing that acrylic will transfer heat well enough to cool the sump. im thinking that if i make the fins 1/16" to 3/32"s thick and space them around 1/2" apart that it should cool the fins. idk it should be a good experiment.

I can definitely see the attraction to acrylic...

but

Copper - 401
Aluminum - 250
Acrylic - 0.2
Insulation materials - 0.035 - 0.16

So I hate to be down on the acrylic but you may as well not bother with the fins. It's probably insulating it more than sucking the heat out. It's precisely the wrong material to use for fins.

Remember I don't totally understand exactly how you plan to run this, but I would think the best compromise would be an acrylic res, sitting on a large sheet of copper, and copper fins (or aluminium angle since it's conveniently shaped and okay at conducting heat) attached to the bottom of the copper sheet.

But nobody ever listens to me Best of luck.

lol Scrub i was wanting to keep the aluminum angle for the nxt build i do so i can make your style light trap. i guess i will just have to order some more then. and thanx for the link to the engineering toolbox, this could prove handy.

If ever I buy shares, they will be in aluminium angle Great stuff.

Weird question, you ever gonna fix the link in your sig? I can never find your thread.

thanx for pointing that out i thought that i had it fixed i will work on it again. ya i use to work with ALOT of aluminum angle and it is some pretty good stuff.

alrite got it fixed and added another link to my home made(or should i say work made) bong. thanx for pointing out that my sig was still messed up i never actualy checked it.

No worries bro. We are such a bunch of shambling stoners. I pointed it out to you originally, then you fixed it but it wasn't fixed, then straight after I think it was discobiscuit that pointed out it wasn't working and you must have thought he was talking about the last sig, lol. None of this probably makes any sense but it's funny in my head. Glad you got it working and goddamn, we even get a bong link! It's like xmas I'll check that out, peace.

i was looking over that chart and i noticed that carbon steel has a rateing of 43. seems alot better than other materials that are cheap and accesable for a sump. my only concern would be that carbon steel rusts and with the water being oxygenated it would probably speed up the process. what kind of paint could i use that would stick, not corrode off, and not be detrimental to the plants health(and mine)?

Don't know anything offhand mate sorry. There is only one idea left rattling round my head and that's to weld an aluminium res + fins, and find out what they use to coat the inside of drink cans, and use that to seal it. Perhaps you could use that to seal your carbon steel too.

i was thinking today about the thermal compound you mentioned at the begining of the thread. would the thermal compound stick to the aluminum well enough to coat the inside of the sump? if so that would work great. im not sure if im going to try at the sump anytime soon. mainly because of the cost and the time it will take to build it.the more i plan it out the more i realize that it will drastically slow the entire build of my mini fridge. if i had the proper welding machine it wouldnt be a problem but momma wouldnt like a purchase like that for a toy like that. my hopes are that someone will give it a try after reading this thread but i doubt that will happen as your the only one that has posted any replies and the views are a bit lower than i thought the thread wouldve gotten. im also hopeing that Aerohead will give it a try in his wine fridge build, im sure he would do a great job fabricateing it. idk. i do apreciate all the input you have given, and when i decide to build it i will definitely let you know and will be hitting you up for some more advice.

No worries man. The funniest bit is that I don't even technically have a res, always mixed it on the spot.

would the thermal compound stick to the aluminum well enough to coat the inside of the sump?

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You mean build an alum sump, and thermal compund as the sealant/inner coating? Hmmm I don't think it's gonna work at all. I have only ever changed one CPU in my life and I bought some thermal compound. It's expensive for a small tube, and I can't remember exactly, but there were some heavy warnings about it. Don't get it on your skin or don't breathe it, or something like that. Sounded like toxic stuff. So it's only a guess but it doesn't sound like a good idea.

Aero always surprises. I hope he gives it a try.

you know Scrub i gave it some more thought today and iv decided to go on ahead with the sump. all we have to do is figure out some kind of non toxic lineing. i really think that if it could be made entirely from aluminum that it would show great results. it may take a while to get it built but so far everything about the mini fridge build has been slow. so il just be patient and build one bad ass mini fridge. peace