Pelter voltage

[jtroutma]

Has any one seen 48V pelters? Higher?

I have heard about 24V pelters but I came up with a nice idea for a watter chiller and 48V pelts would be ideal (since having high amp 12V pelts kinda scare me

Just a thought....

[Butcher]

Two 24V peltiers in series could be run froma 48V power supply.

[jtroutma]

Ok... well then two questions.

1) Where are some places that sell 24V pelters?

2) Are there pelters that are designed to run at 48V?

My idea is that in a water chiller that only uses a water block sandwiched between two high wattage pelts doesnt have enough contact time with the frozen waterblock.

WEll what if you were to make a vertical res. with large heatsinks (say old PII heatsinks vertically stacked) in the res. being chilled by say (4) 156W 24V (or 48V) pelts? The water would sit in the res for a few seconds and have to filter down throught the fins (plently of surface area) and then be pumped out the bottom all nice and cold.

Peliminary calculations came out that it would be ~600W worth of cooling in that type of a setup and might just give the water enough time to cool down; especially if the water had to wait `10-15sec before it was pumped back into the CPU water block.

What do you guys think? Crazy?
<shrug> just a brainstorm one night while trying to fall asleep....

[Butcher]

1) tedist.com and dangerden.com

2) Never seen a pelt at 48V but as I said two 24V in series make a 48V, also for 4 you can do two parallel runs of two pelts in series.

[jtroutma]

Thanks for the info Butcher

I am collecting info for this "theoretical" project

[mr Voodoo]

Don't run peltiers on the Umax, about 75% of Umax is most effiant, effective (bad speling i know ) So 18V for the 24V pelt would be fine.

[ 09-15-2001: Message edited by: mr_Voodoo ]

[LightningCrash]

efficiency doesn't mean jack squat.

cooling power is what counts. most peltiers deliver their maximum cooling power at their suggested voltage.

when you drop the voltage of a 24v pelt to, say, 18v, you may make the ratio of heat transfered:heat generated lower, but your overall cooling capability is adversely effected.

[Butcher]

Efficiency does mean jack squat, if you're putting out more heat the hotside tends to be hotter, cancelling out the effect of having more cooling power. In general 75-85% works best, but you should try it out to be sure.

[mr Voodoo]

Originally posted by LightningCrash:
efficiency doesn't mean jack squat.

cooling power is what counts. most peltiers deliver their maximum cooling power at their suggested voltage.

when you drop the voltage of a 24v pelt to, say, 18v, you may make the ratio of heat transfered:heat generated lower, but your overall cooling capability is adversely effected.

If you run the peltiers on 75% of Umax then you'll have around 90% or more of the Qc left but you have reduced the heat the peltier itself produce a lot, about 40-45% less.

You will probably have o lower temprature on the hotside and the peltier will be easier to cool. And you'll have a lower overall temperature!!

But of course if you have an EXTREMLY good cooling on the hot side you'll go for Umax.

[ 09-16-2001: Message edited by: mr_Voodoo ]

[Kevin]

Yeah grab the pelts from TEDist.. but be advised it is not reccommended to run a 24v pelt at 24v. Supposedly the lifetime is seriously decreased. Run 'em at like 20.
-Kev
mmmm... dual 24v pelts...

[jtroutma]

Well the whole reason why I wanted 48V pelts was because I wanted to get a 48W powersupply to run these suckers instead of a 12V powersupply.

My idea for a chiller will require about (4) 156W pelts and I would much rather use a 48V setup becuase of lower amperage in the system. 24V pelts will also work (2 parrallel sets of two 24V pelts running in series).

Running the pelts @ 20V might be plausable however it would be more difficult to control the current.

Oh well it was an idea.....