Help out a newb with some experience

[aeon flux]

Basically Im new to bong cooling and evaporater cooling. I've done tons of water cooling but with all radiato setups and tons of phase change work. I can go on and on about theory of how to move heat and transfer heat as I work for a weatherization company and thats all we deal with.

Anyway I am kinda confused as to how this bong cooling idea works. Bascially as you were explaining it to a child tell me how it works, how it's setup, and the theory behind it? Thanks very much in advance.

[Volenti]

Originally Posted by aeon flux

Basically Im new to bong cooling and evaporater cooling. I've done tons of water cooling but with all radiato setups and tons of phase change work. I can go on and on about theory of how to move heat and transfer heat as I work for a weatherization company and thats all we deal with.

Anyway I am kinda confused as to how this bong cooling idea works. Bascially as you were explaining it to a child tell me how it works, how it's setup, and the theory behind it? Thanks very much in advance.

For water to evaporate it needs energy (heat), that heat comes from the water left behind which becomes cooler as a result.

A good evaporative cooler will expose as much surface area of water to as much airflow as possible, you want to evapoate the water, any schemes to try and re-claim the evaporated water in any practical/efficient manner are doomed to failure.

[IYIENACE]

Originally Posted by Volenti

any schemes to try and re-claim the evaporated water in any practical/efficient manner are doomed to failure.

Hi - Cool! A bong forum lol.
Volenti mind if I argue your above statement? I'm building a bong too. (I have 8' of 4" 1/4" thick clear acrylic on the way )

I have been following threads and articles and researching everything I can get my hands on to try and make this as different yet efficient as possible...here's what I've come up with.

In the evaporative cooling industry apparently the most efficient evaporative cooler is not the direct contact evaporative cooler [EC], but a newly patented 2 stage direct/indirect EC.

In stage one, the incoming air passes through a heat exchanger, drying it somewhat. This heated drier air then enters stage two:
Where it passes through a wet pad. The greater the thermal difference, the greater the cooling effect.
Common EC reach wet bulb at optimum conditions. Using a 2 stage EC it is possible to reach much lower temps than wet bulb, maybe 4-5*C less.
Another major benefit of 2 stage EC is that the humidity leaving the EC is much lower. (55-65% Humidity if I remember correctly)
Being indoors and using central heat & air I assume this will be absorbed fairly easily.
Another significant advantage is that with reduced humidity, less water loss through evaporation.

This is my plan for building a simple 2 stage ECT. [Evaporative Cooling Tower]

2 Pieces of Acrylic tube 4"id x 24" & 18"H. (A 3rd piece 12"H will serve as a reservoir)
The different heights are basically for appearance - it should look something like a "spire" effect.
Pipe #1 (18"H) will have a fan blowing in ambient air. From the CPU etc. (hot water) Tygon tubing will connect from the computer (insulated) to 1/2" copper tubing coiled tightly inside #1. (*The water cooling pump will be housed inside this tube as well, to add any heat to this pipe instead of inside case*)

Now - Pipe #1 will be joined to pipe #2 (24"H) with a piece of the same 4"id pipe, cut to fit - and laid horizontally to form kind of a breeze way(?) for lack of better words...

The air will flow down through pipe #1 forced through the center of the coiled copper pipe and into the crossover tube. It then hits a wet pad as it enters pipe #2 and turns upward where it passes over a second series of wound copper coils.
Near the top of pipe #2 is a simple drip pan or tubes that deliver water from the very bottom of tube #2 to the top where it simply drips down onto the copper tubing and the vertically mounted wet pads. For maximum cooling the copper tubing (now basically a simple radiator) will be mounted as near the wet pads as possible, where the hotter, drier air will pass over the wet pad picking up moisture and immediately come in contact with the copper tubing....it will then continue upward where it will pass through the dripping water and on out of the top of tube #2.

This has other advantages aside from those mentioned above.
The actual liquid cooling the CPU or GPU etc. operates within a common closed loop. The liquid won't evaporate unlike the water in the ECT, and additives that most find noxious such as water wetter won't be an issue. UV dye can also be used w/o evapotration issues, not to mention the water being fouled like in an open scenario.

It probably sounds way more complicated than it is, but there are very few parts and it should be very efficient if I get lucky and put it together right.... The biggest expense is copper tubing. Footprint is also small due to the increased efficiency. At least in the commercial model it is lol.

Anyway, my tubing should be here tomorrow and I plan to start right away. I plan to measure temps of both air and water at various entrance/exit points to get an idea of the overall cooling ability.

It's obviously not as efficient as cooling "air", but that can't be helped since I need to cool liquid.


If only pipe would clear my graphics card, I would put a 3-4" pipe straight up through my Antec to draw in that nice hot dry air from inside my case! Have that hit a wet pad 1/2 way up and pass over a coil at the top....now that would be sweet. But I don't feel like buying another case just yet.

~Robert




Please feel free to correct me on any info I stated incorrectly. I have been debating this to myself for a week now and it would be nice to get opinions, suggestions, corrections..

[lolito_fr]

Hi and welcome to Procooling!

Its always interesting to see new ideas here, IYIENACE. However, If I followed your description of a 2 stage EC, and compare it to the direct/indirect cooler you mention, I think you may be missing something. As evaporation by itself can't bring air (or water) below dew point, aren't you going to need a phase change unit (dehumidifier basically) to pre-dry the air?
As I see it, this is what you are trying to do with the first coil in pipe #1. But the water in this pipe is only cooled by evaporation, so it won't be cold enough (IMHO) to allow any condensation to happen.

... it should be very efficient if I get lucky and put it together right.....

Check Volentis' post above

[MadHacker]

Me I know little about bong cooling except from what i have read... :shrug:
but IYIENACE does make some sence to me...
take lots of pictures when you make it... if it works as well as you predict...
you may revolutionize bong cooling

[pdf27]

Originally Posted by IYIENACE

In stage one, the incoming air passes through a heat exchanger, drying it somewhat. This heated drier air then enters stage two:
Where it passes through a wet pad. The greater the thermal difference, the greater the cooling effect.

This is the bit that confuses me. If I understand correctly, you're using the cooling fluid from the system to pre-heat the air. This warmer air then cools some fluid - and this is where I get confused. What are you doing with the cooled fluid?

Also, I think the "low humidity" part is a bit of a red herring as far as cooling goes. The net heat you are dumping to atmosphere will basically be the mass flow rate of water multiplied by the latent heat of evaporation of the water (about 2.5 MJ/Kg at room temperature). The potential efficiency improvement in this system is that you will be able to dump more heat per unit volume of air, as warmer air is able to carry more water. There will be a pretty insignificant change in the total water consumption (a quick look at my steam tables suggests that the latent heat of evaporation of water decreases as temperature increases).

Was going to post more, but too tired...
Let us know if it works - sounds an interesting concept

[IYIENACE]

Originally Posted by pdf27

This is the bit that confuses me. If I understand correctly, you're using the cooling fluid from the system to pre-heat the air. This warmer air then cools some fluid - and this is where I get confused. What are you doing with the cooled fluid?

Also, I think the "low humidity" part is a bit of a red herring as far as cooling goes. The net heat you are dumping to atmosphere will basically be the mass flow rate of water multiplied by the latent heat of evaporation of the water (about 2.5 MJ/Kg at room temperature). The potential efficiency improvement in this system is that you will be able to dump more heat per unit volume of air, as warmer air is able to carry more water. There will be a pretty insignificant change in the total water consumption (a quick look at my steam tables suggests that the latent heat of evaporation of water decreases as temperature increases).

Was going to post more, but too tired...
Let us know if it works - sounds an interesting concept

Wow thanks for the replies! Sorry I haven't replied, I tore down my rig in anticipation (no tubing yet ) anyway - I've been rewiring, reformatting etc.

Ok, firstly let me say again, this idea was patented by a German company, and apparently it is very effective. Things to use for more indepth info would be to Google "2 stage evaporative cooler" "direct/indirect" etc.

Originally Posted by lolito_fr

I think you may be missing something. As evaporation by itself can't bring air (or water) below dew point, aren't you going to need a phase change unit (dehumidifier basically) to pre-dry the air?
As I see it, this is what you are trying to do with the first coil in pipe #1. But the water in this pipe is only cooled by evaporation, so it won't be cold enough (IMHO) to allow any condensation to happen.

The stage #1 isn't really to condense the air, as in a dehumidifier. It's just using some free thermal energy to precool the liquid somewhat. Basically the first tube is what everyone using closed loop watercooled systems with radiators has. Ambient (if lucky) to warm (or even hot in some cases - pun intended) air blowing across a radiator/heater core. Now imagine if you will that same radiator inside a shroud covered by wet pads. Now add a light flow of water across the surface of the radiator it's self. Now if we were only cooling the air - we could put another wet pad and let the cooled air leave the shroud through it. It should be below wet bulb. So what they are doing is using a heat exchanger, then an evaporative cooler. Both of these are potentially very energy efficient as you know so they don't really require high speed fans or pelts or compressors. But they also don't reach the extreme temps, either.

As for the 2 stage,
Here is a picture illustrating the basic unit they manufacture.



And again



I realize this has more than likely been kicked around and I seriously doubt I have stumbled across anything new.....but it makes sense to me and while a cooling tower is really efficient at cooling, there's so much humidity not to mention water loss.
I'm simply trying to combine a heat exchanger and cooling tower and evaporative cooler lol into one little package. :shrug:

The 1st solid idea I had was described in my 1st post. In a sense it was like taking approx. 20' of 1/2" copper tubing, and about a foot from each end start bending the copper into tight coils (that would fit inside a 4" pipe) until you have two coils - connected with a few inches between them. Place both of these into 2 seperate tubes and on the 1st mount a fan blowing air through. There would have to be a crossover path for the air as I mentioned, and the air would cross into the 2nd tube & blow upward where it would pass through a wetted mat. Immediately after it would encounter the 2nd coil (which has water flowing lightly down it btw) and out past the coil & "drip pan."
This is a (very) crude picture of my 1st idea.



Of course the blue=water - red & light blue=air flow - light gray=case - gray-fan - dark gray=main system pump.

I've since changed the plan because I want to put the entire thing into my case.
(Right now I have nothing on my PC, I really want to put in 3dmax and think about it a little more before I cut any thing, so unfortunately all I have is paint tonight lol.)

First some misc. stuff I've found. I bet you guys already have all this...



If I remember most homes have a RH% lower than 30% (w/ HVAC) and my home stays @ 72*f which puts it off of that chart if it is at all accurate.

An illustration of a simple heat exchanger:



High quality examples of commercial exchangers:



Here is a very primitive sketch of my latest brain "storming" lol. I will try to further explain so some of you more informed/experienced/educated/all the above can give input(?)



Damn I've written an essay!

Ok...some of this self-explanatory but anyway here' goes:
1.) fan - exhausted air
2.)drip pan (pan with holes for water to drip through (*note* showerhead not necessary, water doesn't have to be "fine")
3.)a water block lol
4.)1/2" tubing (preferably no 90* unlike sketch)
5.)These have an actual "name" though I don't know it. Let's call them air deflectors. I'm pretty sure their placement is important on air flow....
6.)1/2" tubing
7.)Wet mat
8.)Air vents/holes/openings whatever for hot air intake inside case
9.)catch pan (w/ overflow btw) water drips from top through holes and into heat exchanger, onto wet mat material, whatevers left falls here and runs off back into loop.
10.)1/4" pipe or tubing (I worry that this will be a problem because it controls overflow and can be easily fouled - "crudded up") this tubing runs from a refillable resevoir outside of case and needs only a really small aquarium pump. I want just a steady stream of water....
11.)Main pump (DannerMag 3 in my case)(yes, pun intended lol)
12.)main system (closed loop) resevoir.

Ok now I think that's probably enough breaking of the laws of grammar & physics for one night.

Hopefully my material will be here soon, though now I'm thinking it's too big for something like above. :shrug:
Yes I will continue to take pictures along the way and document all I can. I am excited to start.

~Robert

[pdf27]

OK, so if I understand correctly you're effectively going to be running a standard watercooled (closed loop system), but with some water on the outside of the radiator as well to give additional evaporative cooling?
In that case it might be worth thinking about using something like a heatercore instead of all that copper tubing - what will be critical in this case (pun not intended!) is the wetted surface area of the radiator you are using. Hence, either small fins soldered to the piping or something like a heatercore may be helpful. However, since you are using water on the surface the amount of hot surface area you need is probably much reduced relative to using air as the coolant.
In the case of (5), I think the word you are looking for is "baffles".

What the blower is doing in that company's diagram is using some air to cool water by evaporative cooling. This cooled water is then used to cool the remaining air, which is then blown into the house. The reason that the air being blown into the house is of low humidity is that the cooler isn't adding any extra water to the air being blown into the house - the humid air is all dumped to atmosphere. The part of the system which cools the water is basically identical to a standard bong. What the system does with the water after that is cools air for domestic use, rather than cool a CPU.
The reason it is highly efficient is that the heat removal is effectively free, due to water being very cheap. Using an air conditioner to do the same job is far more expensive as it has to operate as a heat pump, which requires far more energy.
What I'm trying to say is that you'll probably get temperatures somewhere between a bong system and a standard watercooled system using a radiator with this setup (which it is closer to will depend on the design). As a hybrid system it has some of the advantages and disadvantages of both.

Anyway, please post pics when you're done - it should be very interesting to see how it performs.

[IYIENACE]

Originally Posted by pdf27

OK, so if I understand correctly you're effectively going to be running a standard watercooled (closed loop system), but with some water on the outside of the radiator as well to give additional evaporative cooling?
In that case it might be worth thinking about using something like a heatercore instead of all that copper tubing - what will be critical in this case (pun not intended!) is the wetted surface area of the radiator you are using. Hence, either small fins soldered to the piping or something like a heatercore may be helpful.

I have been searching for a core that would fit my project, I did originally find some finned tubes like you mentioned, they are available in all sizes, shapes and material. How costly though, I don't know. I will find out.

Here is an example:



I also considered washers or thin copper sheeting, but seems to be too labor intensive with the available options out there....

[IYIENACE]

double post

[IYIENACE]

Originally Posted by pdf27

However, since you are using water on the surface the amount of hot surface area you need is probably much reduced relative to using air as the coolant.

Please keep in mind that my drawing isn't to scale and the tubes in the heat exchanger would be smaller diameter and higher in count. Probably will be 1/4" copper.

[IYIENACE]

Originally Posted by pdf27

In the case of (5), I think the word you are looking for is "baffles".

Yes! lol there's the word. Sounds much better too.

[IYIENACE]

Originally Posted by pdf27

What the blower is doing in that company's diagram is using some air to cool water by evaporative cooling. This cooled water is then used to cool the remaining air, which is then blown into the house. The reason that the air being blown into the house is of low humidity is that the cooler isn't adding any extra water to the air being blown into the house - the humid air is all dumped to atmosphere. The part of the system which cools the water is basically identical to a standard bong.

Actually, the air is pulled in and some diverts through the heat exchanger-cooling it. Some air that is not diverted is pulled up and across the heatexchanger. That is the indirect cooling.
The air then strikes a wetted mat as it leaves the unit. This is the direct cooling phase.

[IYIENACE]

Originally Posted by pdf27

The reason it is highly efficient is that the heat removal is effectively free, due to water being very cheap. Using an air conditioner to do the same job is far more expensive as it has to operate as a heat pump, which requires far more energy.

Exactly! Plus it's a DIY and that just adds to the coolness factor.

[IYIENACE]

Originally Posted by pdf27

What I'm trying to say is that you'll probably get temperatures somewhere between a bong system and a standard watercooled system using a radiator with this setup (which it is closer to will depend on the design). As a hybrid system it has some of the advantages and disadvantages of both.

You may be right, but honestly I am hoping for far lower temps than attainable by standard rad cooling alone. If I can effectively figure out the 2 stage part I hope for temps settling below wet bulb....it may require a larger device or higher air flow, or something else but I plan to find out.
My main goal now is to build a highly efficient cooler, self contained with nothing necessary but attaching hoses to the fittings exposed and mounting a fan inside the top. It will have the smallest footprint I can come up with. I'm going to call it H2o-X

[IYIENACE]

Originally Posted by pdf27

Anyway, please post pics when you're done - it should be very interesting to see how it performs.

Of course! lol
Thanks for the reply, and suggestions. I will check back this evening - got to go.

~Robert

[Volenti]

Something you may need to keep in mind, is that commmercial evaporative air conditioners are primairily designed to cool the air, and not necessiarly the water.

Though presumably you could have a 2 stage system, with one evaporative cooling setup in a seperate loop that used a large radiator to "pre-cool" the intake air for the other evaporative setup on the pc it's self, but that's getting pretty complicated and rapidly reaching diminishing returns...

[IYIENACE]

Originally Posted by Volenti

Something you may need to keep in mind, is that commmercial evaporative air conditioners are primairily designed to cool the air, and not necessiarly the water.

Though presumably you could have a 2 stage system, with one evaporative cooling setup in a seperate loop that used a large radiator to "pre-cool" the intake air for the other evaporative setup on the pc it's self, but that's getting pretty complicated and rapidly reaching diminishing returns...

Yeah that's what I was saying toward the start of this - the water being in a closed loop simply can't evaporate into open air as with an evaporative cooling tower, it has to dump it's thermal energy into the copper. That's why I want to cool the copper as much as possible.
I have gotten loads of stuff in, but still no acrylic pipe! I finally contacted them and turns out they couldn’t ship the length I needed and so.... just didn't send it period! Oh well, I think we got it straight.
No word on the finned tubing yet, I ordered 50 pieces 24" long. I started putting it in 3d to have some scale / material ideas, here's an early render with just basically part of the heat exchanger. It is to scale though the measurements aren't on it.



The green tubing is for air and water passage, the round copper end tanks will be sealed to hold the closed loop water. The tubes would also be finned.
The block looking thing is a 120mm fan to scale inside the 4" tube. I will finish the drawing this week, and since I don't have the parts for the heat exchanger yet, I have another idea for pulling heat out of the water w/o losing so much to atmosphere. Let's just say it involves an extra zalman 7000cu I have sitting around.

I also bought web space today to document all the upcoming experiments and stuff lol.

Let's hope it can work so we can make those rad guys jealous!


~Robert

[jaydee]

Originally Posted by IYIENACE

Let's hope it can work so we can make those rad guys jealous!

If you can make it fit in a PC Case and cost less than $20 then you will make me jealous. Other wise a rad it is.