Ultrasonic2 (muffy)

Here's my TEC calculator that i made for my Overclocker.net mates. Enjoy



BETA 2.4

Download from here:
http://watercooling.co.nz/node/60

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ChielScape

1.4 already? great. will d/l ASAP.

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Scarlet Infidel

I was just going to ask about parallel TECs! This program is getting very useful. I have a few queries about the ambient temp usage but ill wait ubntil ive tried the program.

Scarlet Infidel

Right just tried it. Im not quite happy with the way ambient is dealt with.

The values that come with the peltier modules (such as 27 degrees with mine) are not really anything to do with ambient temperatures. All it is saying is that the supplied specification are correct when the hot side of the peltier is at 27 degrees.

Of course the hot side of the peltier is going to be a bit above ambient hence they usually give example figures at about 27 and 50 to give example figures for very good and relatively poor cooling of the modules.

I wonder if anyone knows any equations that take into account the hot side of the TEC and alter the resistance and other specs of the peltier appropriately.

If I have misunderstood or anyone knows any better, please feel free to correct me, im very new to all this.

Edit: looking at your other modules, they all have ambient figures qouted at around ambient. I wonder why there is a difference. Did you get their specs from the manufacturers websites or from enthusiast sites/shops?

Ultrasonic2 (muffy)

Right just tried it. Im not quite happy with the way ambient is dealt with.
Fare enough.

The values that come with the peltier modules (such as 27 degrees with mine) are not really anything to do with ambient temperatures. All it is saying is that the supplied specification are correct when the hot side of the peltier is at 27 degrees.

Yip your correct
Heres some numbers on a 172 watt TEC at different temps




I wonder if anyone knows any equations that take into account the hot side of the TEC and alter the resistance and other specs of the peltier appropriately.

A 172 TEC at 18.6c moves 172watts of heat to ambient while using 361 watts of electricity .
@ 0c it moves 149.5 watts to ambient while using 361 watts of electricity

Watts used is ralative to qmax at "X" temp

The 245 and 437 numbers are questionable because i made up the ambient temps for them .. I had planned to ask you lot to get accurate numbers for me . I believe the 226 and the 245 watt TEC to be the same thing but at different temps.. So can some one help me find the CORRECT numbers for them.

I believe can work out the equation to predict correct Qmax based on "X" Th temp . till take time though.. i do need to do it as it'll change things quite a bit.

Can some one find correct data for the 245 and 437 TEC's please

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Ultrasonic2 (muffy)

The other thing i need to account for is that the temp of th / ch also effects dTmax ..ie at th of 0 results in a dTmax of 58.7 if th is at 100 then its 93.8

Scarlet Infidel

Im glad I understood things correctly. This is where I struggled to find the equations I wanted to get everything worked out precisely.

All I can say about the Th is as ive already said most manufacturers qoute values at 27 degrees and 50 degrees. However, sellers often qoute the 50 degrees values to make the modules sound more powerful. I'll have a quick look aorund for numbers.

Edit: being a bit stupid at the moment, they use 27 degrees c because thats 300 kelvin (why they use 300k im not yet sure but its a nice number) and I now assume they sometimes use 50 as an expected normal hot side temperature in the average system.

Scarlet Infidel

After a quick look I find alot of references to saying the 245w and 320w modules are the same but at different temps. It seems to be a CP1-12726. The specs page doesnt give much info though such as the crucial temperature.

I have seen these figures qouted though (they are about what I was expecting):

Qmax = 320W Th = 50C
Qmax = 243.5W Th = 26.8C

Scarlet Infidel

Also, where did you get a copy of the Kryotherm software? Im finding it hard to get hold of.

Ultrasonic2 (muffy)

300 kelvin = 26.85 .. good piont

i've fixed the qmax V th temp
now it's on to dTmax V th temp

My numbers aren't exactally the same as the Kryotherm program because im making the assumption that the rated qmax and dTmax is quoted at the rated temp "300k" . However the Kryotherm program puts qmax at 18.6c and dTmax at 26.85 (300k)?