Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
peltier elements
#11
The other thing about cooling is the energy you need goes up really steeply with increasing temperature difference.
Eg for cooling say 30C down to 25C vs 30C down to 20C you'd need quite a bit more than double the energy.

re the heatsink compound, if it makes a bridge from the cool side to the hot side, you'll be "short circuiting" the heat-flow.
You might have better luck with a sheet of the thin thermally conductive insulation stuff instead (ie stuff they use under transistors)

Use fans on both sides....

A good quality DC fridge guts could probably be used....
Running off solar, DIY & electronics fan :-)
Reply
#12
Thank you for all of your replays.
I will look into them.

I was looking on one of those links...making beer is not rocket science...great sentence, had me laughing.
What people do, add, and the length they walk to make a good beer, wine or stronger alcohols(read bad).
Oke i am wondering of.

That project idea with a freezer was also playing in my mind, to "store" the cold for later use.
Run some coils (closed system with a pump)in the coolant.
A good friend of mine did this experiment, loooong ago, although he made two mistakes.
He used plane water and had a old freezer.
Today, the freezers are way cheaper (also in use) and the compressors are in better quality.


First i am going to scrap of the thermal paste.
Glad i did not make a picture of the other side, wow.
I have a suspicion: when i scrape off the paste i will have enough for all of them and have left over.

I will also add a ventilator to each cold side.

How do you mean stack 3 on top off each other?
Cold/hot against hot/cold against cold/hot or c/h,c/h,c/h?
I think c/h against c/h?
Only power the bottom(cold side) and the top or all three.
Lower current? how low, 5 amp 10 amp? or just cut it in half 7,5 amp?

Thanks in advance
Selling everything at marketplace.
Reply
#13
(08-17-2019, 05:48 PM)100kwh-hunter Wrote: How do you mean stack 3 on top off each other?
Cold/hot against hot/cold against cold/hot or c/h,c/h,c/h?
I think c/h against c/h?
Only power the bottom(cold side) and the top or all three.
Lower current? how low, 5 amp 10 amp? or just cut it in half 7,5 amp?

Yes, they'd stacked c/h-c/h-c/h, and then power them in parallel. This makes the temperature difference much more manageable and easier to hit cooler temps.
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
Reply
#14
Stacking them c/h-c/h-c/h like Korishan says is the go, you would connect their power wires in parallel, eg all red wires connected to +ve power and all black wires connected to -ve power so they all get the same current.

Be sure to clean off all paste on the edges of the units.

Also consider that fast thermal cycling on/of/on/off or extreme temps can shorten their life (you get fractures of the elements inside each unit). Ramping the temp up/down more slowly is a good idea if can.
Running off solar, DIY & electronics fan :-)
Reply
#15
(08-18-2019, 05:26 AM)Redpacket Wrote: Stacking them c/h-c/h-c/h like Korishan says is the go, you would connect their power wires in parallel, eg all red wires connected to +ve power and all black wires connected to -ve power so they all get the same current.

Be sure to clean off all paste on the edges of the units.

Also consider that fast thermal cycling on/of/on/off or extreme temps can shorten their life (you get fractures of the elements inside each unit).  Ramping the temp up/down more slowly is a good idea if can.
I found in my experiments that a bigger issue than cracking was the condensate.
You can get sealed units that helps with this.

The modules are usually very robust and you won't find a problem with them cracking.
From what I understand going slowly is only a couple of second ramp  usually solved by adding a capacitor.
The modules don't like AC so a capacitor doesn't hurt anyways.
Reply
#16
Interesting - did you find a method of controlling the condensing water problem?
Running off solar, DIY & electronics fan :-)
Reply
#17
(08-18-2019, 12:46 PM)Redpacket Wrote: Interesting - did you find a method of controlling the condensing water problem?

as alreading mentioned ... buy pre-sealed units.

Silicone isn't good -->https://tetech.com/peltier-thermoelectric-cooler-module-calculator/moisture-protection-ruggedizing/
Reply


Who read this thread?
39 User(s) read this thread:
Sean (08-19-2019, 11:41 AM), Jim Jr. (08-17-2019, 06:38 PM), w0067814 (08-24-2019, 08:44 PM), chuckp (08-18-2019, 10:43 PM), emuland-metroman (08-19-2019, 07:45 AM), Wolf (08-19-2019, 12:30 PM), Bastler_Ro (08-08-2019, 07:44 PM), stevelectric (08-19-2019, 01:54 PM), ajw22 (08-18-2019, 09:53 PM), OffGridInTheCity (08-08-2019, 06:45 PM), 100kwh-hunter (08-19-2019, 07:35 AM), Otakar (08-10-2019, 02:00 AM), 3xtr3m3 (08-12-2019, 12:49 PM), drnickriviera (08-10-2019, 01:04 PM), LPG (08-09-2019, 11:53 AM), berthfield (08-08-2019, 07:17 PM), Magnum164 (08-10-2019, 11:49 AM), Gadabout (09-09-2019, 09:02 AM), Riplash (08-19-2019, 01:08 AM), Bubba (08-18-2019, 09:32 PM), Ibiza (08-22-2019, 12:33 AM), Korishan (08-18-2019, 10:46 PM), PAF (08-09-2019, 06:51 AM), jdeadman (08-19-2019, 07:23 PM), wim (08-19-2019, 07:00 AM), rebelrider.mike (09-07-2019, 05:50 AM), watts-on (08-18-2019, 02:47 PM), Stefaan De Ridder (08-18-2019, 01:55 PM), Geek (08-19-2019, 12:28 AM), Jon (08-08-2019, 09:24 PM), Oz18650 (08-10-2019, 09:35 PM), djuro (08-09-2019, 03:23 PM), drchips (08-11-2019, 12:13 PM), gpn (08-19-2019, 04:30 AM), Dala (08-10-2019, 03:23 PM), Crimp Daddy (08-13-2019, 06:27 PM), Redpacket (08-19-2019, 09:11 AM), completelycharged (08-10-2019, 01:43 PM), barry (10-20-2019, 09:48 AM)

Forum Jump:


Users browsing this thread: 1 Guest(s)