Post Rad Chiller Concept

[n00b 0f l337]

Thank you Ultrasonic, we know how conservation of energy works.
However, it DOES work. Sure the radiator takes a bigger hit, but if the radiator can take it, your fine, just wasting electricity for the gains.

[Ultrasonic2]

Well im not going to argue because i wont get anywhere. However it's illogical ...

Any possible gain on the cold side will be lost on the hot side. = pointless

It can't possibly work and it doesn't.

However you'll probably say it does so we'll just leave it at that. :-)

[n00b 0f l337]

Your correct, however your viewing the water temperature as a hole and average.
Using this method, part of the water loop will be colder then the other part. A good bit at that. The TEC's use power to create this gradient.
Trust me, taking a holyer then thou attitude won't work, especially with the person who currently HAS THE SETUP IN HAND. And someone who's been in the TEC game a long time.

[Ultrasonic2]

Trust me, taking a holyer then thou attitude won't work, especially with the person who currently HAS THE SETUP IN HAND. And someone who's been in the TEC game a long time.

If we reversed the effect and had a flow rate of infinity and a loop with C/Ws of 0 then the water leaving hot side would = ambient and the temp leaving the cold side would = ambient

Since it's one loop what ever effect you apply to the cold side will be applied to the hot side. Meaning no gains with the chiller since it's all one loop and they are canceling each other out.

Im dont believe im taking the holyer than thou attitude i have only debated the Principal that this chiller works on. i have not suggested that people take my view because im better than any one or that i have more experience than any one else. i have debated the facts.

How long someone has been doing TECing should be irrelevant to any discussion and has no bearing on what's right or wrong.

If you want to get into a credibility contest i can hold my own in relation to TEC. However there's no point in doing that. Im probably an unknown to you and your an unknown to me. I would happily debate the principle that this single loop is based on with anyone.

Indeplth TEC knowledge is mostly irrelevant to this debate anyway as the debate we're having revolves around the effects of flow rates.

[flak-spammer]

I really don't understand why someone would want to do a single loop chiller, really it just makes the concept pointless. The only way to make it feasible is if the rad in question was a car rad but even then I couldn't see if working well since flowrate has an overall effect any increase in flow rate increases cooling of hotside and decreases cooling on coldside. There is no right and wrong way to do it, however there is an efficient and inefficient way and this falls into the inefficient category. However whatever you want to do is whatever you want, I'm inclined to say I'm more interested in Ultrasonics design. You have a very nice thread on OCN and I'm actually very amazed at how well you have done. I think this whole post rad concept is going to fail to some extent since anything you apply to one part of the loop will effect any other given part of the loop. That is just how I think.

[n00b 0f l337]

Of course this is inefficient, we do know that; however technically it has it's upsides.
For instance, the TEC's increase the delta that the radiator operates at, thus increasing its efficiency.
And yes, higher flow rate will bring this system closer to ambient; however you are still operating a heat gap at the processor.

[Ultrasonic2]

Of course this is inefficient, we do know that; however technically it has it's upsides.
For instance, the TEC's increase the delta that the radiator operates at, thus increasing its efficiency.
And yes, higher flow rate will bring this system closer to ambient; however you are still operating a heat gap at the processor.

I agree that at low flows you will see a big temp difference between hot side out to cold side out of the TEC.

So you'll see a lower temp going in to the CPU block than at high flow rates. This also means the temp exiting the CPU block would be higher than with high flow rates too. Net affect is point less. The same idea applies the the radiator.


Even if the suggested system did work why bother ? Why not go to a duel loop system. one loop with the hot side and rad. and the the other with the cold side and CPU. This way you get tangible results for the rather large investment of chiller TEC's and electricity used. All you'd need is the extra pump.

Martin posted this chiller on OCN and at the time i protested against the proposed plans for it. I tried to sign up to this forum too but that took aaaaggggeeeessss so by the time i could post their wasn't much point as this tread had died.

From the OCN post on this chiller i actually thought the proposed idea was to have 2 loops a hot side and cold side loop but with radiators in both sides which would result in minimal benefits.

[Cathar]

Oh a bunch of us did, Cathar's was two pelts. He found he needed more power.

Yep, at least 4 x 226W pelts needed for good performance when run at 5V (or about 30% Vmax). Makes for very good CoP. Need a dual-loop setup (which is what I was always running). Single loop setups are for the birds if you want effective results, or unless you're prepared to run about 10x TEC's in serial with about 10x radiators and a very low flow rate, and even then it'd be unspectacular.

The biggest issue with TEC's is the limited temp delta across them at the lower voltages. Have been theoretically toying with the idea of a two-stage chiller with 3 loops to reduce temperatures further.

Insulation of tubing is very important for success, and absolutely must not be under-rated in terms of its importance.

[Ultrasonic2]

Insulation of tubing is very important for success, and absolutely must not be under-rated in terms of its importance.

yes i agree with that mine attracts condensation badly at low temps

[Cathar]

yes i agree with that mine attracts condensation badly at low temps

Not just for that, but also for better temperatures. The tubing absorbs quite a deal of heat from the environment if not insulated.

[Ultrasonic2]

oh yes for sure

[NaeKuh]

lol...

this project was changed so many times.

At first i wanted to see if it was possibly. I did my own tests, and its very difficult if not impossible to have a rad attached on the same loop. You hit below ambients and the rad takes you back up.

The final config i think i decided for this was to use 4 x 437W pelts, or 5 x 226W pelts, however the heat i calculated would of been massive.

I honestly was expecting this so i did dedicate my oracle station to cool the hot side, and go with cathars original idea:

The hotside will most definitely be cooled by this monster:


I figure that setup is probably good for even the 4 x 437W pelts + load.

All i need back is the TEC blocks, and i think im good to go.


Quesiton tho, what kind of PSU would 4 x 437W Pelts require? That im kinda still scared about.

oh and i know someone is gonna ask with all this money i spent why not just get a phased chiller, the answer to that is i already did.
i get bored of things really fast, and i dont know what it is about TEC's.

I just had to give it a shot without sparing any expense.

[Ultrasonic2]

Question tho, what kind of PSU would 4 x 437W Pelts require? That im kinda still scared about

Well that depends on your goal . presumably you'll be running them at less than imax or umax as you'd be up for 3500 watts ish.

[NaeKuh]

Question tho, what kind of PSU would 4 x 437W Pelts require? That im kinda still scared about

Well that depends on your goal . presumably you'll be running them at less than imax or umax as you'd be up for 3500 watts ish.

i would take down the entire power grid on my block if i drew that much power.

[jcool]

Holy crap NaeKuh, now THAT is some ed up you got there

Question, do the 4 fans in the middle really improve cooling? Wouldn't 1 row of fans between the 2 rads be enough?

[ownage]

The Noobinator brings in the big artillery to pwn mr. aircooling!

[Ultrasonic2]

I honestly was expecting this so i did dedicate my oracle station to cool the hot side, and go with cathars original idea:

And what is cathars idea ?

[NaeKuh]

And what is cathars idea ?

hot side watercooled.

Simple and efficient.

i believe nol had sandwitched 8 tec's on a big heat sink aircooled last.

[n00b 0f l337]

Yep, tried that. Some bigger pelts on it I had lying around (breaking down your loop tonight for repack to you and will include them).
Want the big ass heatsink? It'll be expensive to ship, but it does work. (It also weighs like 25lbs)

[eligray]

Its an interesting idea to have a self-chilled loop. However, I believe that it would be wiser to just splurge $30 on the extra pump and get a second dedicated hot-side loop.

Fun read though

I wonder what the ideal flow rates would be in a self-chilled system...

[zipdogso]

well...I don't want to get drawn in to an argument so I'ii say my 2 cents and butt out. Basiclly I am in argreement with ultrasonic.

TEC's are not chillers they are heat pumps and all they do is move heat from one place to another but they are able to move large amounts of heat from an object hence the "cooling effect".

A "self chilled" single loop only works with additional cooling to the TEC ie rads, they are what actually chills the coolant and you need loads of rad cooling to cool both the heat removed from the object plus the heat generated by the TEC's themselves. In reality there is not much point in using a TEC in such a setup you are just taking heat from a point on the loop and putting it back plus the heat generated by the TEC somewhere else in the loop. there can be no "chilling effect" the only chilling is done by the rads. Hence it appears a very inefficient system...not surprising !!

The only correct usage of TEC's is one cold loop ( or direct attachment of the TEC.) and one hot loop. That way you can remove heat from an object or coolant and then disperse the heat in another location that is the only correct usage of TEC's.

[NaeKuh]

well normally with that big sink i was thinkn of paralelling the blocks. and air cooling the hotside.

since id be doubling the TEC's i would think the hotside could be aircooled efficently no?

[Ultrasonic2]

well it'll never bee cooled as inefficient as water cooling but it maybe about to give you acceptable results . Not that i've seen the heat sink

[flak-spammer]

It really depends on the C rise from ambient that the heatsink has, and how much air is being passed through it but I'd say the temp would be atleast 10C higher than water more likely 15-20C. I suppose that really depends on heatsink surface area and volume of air blown.

[Uncle Jimbo]

It really depends on the C rise from ambient that the heatsink has, and how much air is being passed through it but I'd say the temp would be atleast 10C higher than water more likely 15-20C. I suppose that really depends on heatsink surface area and volume of air blown.

If he did not cut down the heatsink, it should deliver better than .04 C/W with good airflow (1100 LFPM or better). That's not quite as good as the best water rig. You will see a 10C rise for each 250W. The better rads will show 5C for 250W (.02 C/W) with good fans and flow rates.