Has anyone ever considered using a peltier junction to cool their PMD?

A local surplus store has them for $50. The junction is about 6" x 6", and already comes with both heat sinks (I would have to remove the cold side sink and attach the PMD to it). It runs on 12 v using ~3.6 amps.

A good idea or a waste of time :confused:

Don't see why it wouldn't work. Would definately be able to cool it down a few degrees.

I'd say it depends on how much heat it can remove and if it could keep up with the "heat soak" that occurs after engine shut off. It would have to function for some time after the key was turned off.

I'd say it depends on how much heat it can remove and if it could keep up with the "heat soak" that occurs after engine shut off. It would have to function for some time after the key was turned off.

I was thinking the same thing, but if the junction was working correctly during the running time, the heat sink on the 'hot' end of the junction would continue dissipating heat in much the same way was the 'fsd coolers' on the market right now do (passive conduction). Even if this was NOT the case, a person might be able to put in a time delay switch that allowed the junction to continue operating for a minute or two after the ignition was turned off. Any other thoughts? Perhaps I should be a guinea pig and give it a shot...after all it is only a $300 PMD -:t . However if someone were to donate a 'good used' PMD I would definately run some tests with the junction...:ro)

This sound's interesting Chrisk 1500.Where is that surplus store.I run a FSD cooler with a 250cfm 12v fan mounted on it mounted behind the grill and never get over 87 degee's towing on hot day's on the hyw and about 115 in city traffic.After shut-down the temp always drops so i never installed a timer.

I installed a peltier, but only ran it for about 1 week. It keep my PMD real cool durring operation, but I found that when I shut the truck down all the heat in the heatsinks came right back through and got the PMD real hot with no air movement from driving to cool it off.

I think that those coolers max out at about 40°F differential. Meaning if it's 180° under the hood, the cool side will only be about 140°F. At least that's the way my cooler works. Don't know if yours is any better or not. Still better than just "underhood" temp.

If you do it, let us know how it goes. I'm interested to see too. See if you can get some temperatures on it.

A little off topic, but I had once thought about machining flat the top of the intake manifold and installing a peltier between another large heat sink, either a liquid-cooled plate or a large finned aluminum block. The idea was to remove or transfer the heat away from the intake manifold and into the engine bay. Then I thought about mounting copper plates or fins inside the manifold to really help the heat transfer process. Well, after building a model or two, I came to the conclusion that peltiers are a lot of fun to mess around with. Hwever, other than cooling your computer processor, I think their applications are limited.

, I think their applications are limited.

Well, I respectfully disagree. Peltiers ware basically what makes fridges works. If a big peltier can cool a fridge, a small one can certainly cool a PMD.

The surplus store is called 'Princess Auto'.

Here is one of the websites I have encountered on my quest for 'peltier knowledge': http://www.dansdata.com/pelt.htm

Keep in mind that the peltier they are talking about is a small one used to cool CPUs. The one that I am looking at is MUCH larger and is industrial quality. The junction they talk about can produce a difference in temp from one side to the other of 72* C.

The thing I am concerned about is the condensation in the winter time. I am sure if I think long enough, I should be able to overcome this problem (perhaps by mounting the junction so that the fins run parallel to the ground so that the water just runs off???).

I think I am on to something with this, and for $50 I think I will give it a shot. Now I just have to find a cheap PMD and :grd: .

Why not put a temperature switch of sorts to control the operation so that when it gets cool it doesn't run. I know in cold temps it would probably ice over.

Keep in mind, that PMD is going to be producing heat, year round.... icing up might not be a problem even in the winter time. Worth an experiment.

I will trade a good used PMD for one of the peltier devices, and we can try it on 2 trucks.

I will go out this afternoon and buy one. Then I will post pics of it and you guys can give me some feedback. If anyone wants one I would be more than happy to work out a deal with them to get them one (at cost of course). For you Americans this could be a CHEAP deal - I think $50 Canadian should be around $5 American ):h .

I thought about it last night, and another concern I have is attaching the PMD to the junction. I may have to remove the cold side sink, cut off the fins, and tap into the 'now flattend' piece of aluminum.

Chris not wanting to dash your experimentation but the best method thus far has been to remove the PMD from out of the engine bay, search for a post Imade last year, points to ponder to see what you are up against when leaving the PMD in the engine bay, remember a refrigerator is normnally in a 80F or less room temperature, under hood temps are as high as 250F,

I hear what you are saying about underhood temps, but if people continue promoting the idea of FSD coolers mounted on the intake, I see no reason why an active cooler would not work underhood.

This junction/heatsink is roughly 1/2 the size of the PMD coolers sold by DSG/Heath/Kennedy so even if the junction doesn't work, I can always take the heat sink off of it and use it as a stand alone heatsink cooler.

I am going to the store now to pick it up.

**Theory is just that....theory. Let's :grd: and see what happens**


EDIT - If underhood doesn't work, maybe I can mount it in the cab somewhere...

I started with the underhood solution, it's better than factory, but not a permanent one IMO; again do a search for my PTP post and you will see why I disagree with the underhood on intake mounts as the final fix. Out of engine bay IMO is only way to go regardless which method of heat sink you use.

Although I am quite familiar with Peltier effect units, I agree with the Doc. Getting things out of the engine bay will provide ambient temperatures of under 100 degrees (typically) and will represent a decrease of over 150 degrees over using any kind of cooling in the engine bay. Also, passive cooling has no active components to fail. There are no temperature sensors, no switches, no current drain.

My personal goals are maximum reliability followed by performance. That's why although I considered cooling fans and Peltier junction devices, I ended up using a passive heat sink and an extension harness. The less active components, the better.

I however support your experiment and will be interested in your results.

Sincerely,

Rob :)

Here are the pics of the junction.

I am sorry about the poor quality. My digital is a POS.

SIDE VIEW:

http://www.geocities.com/chrisk1500/side.jpg

TOP VIEW:
http://www.geocities.com/chrisk1500/top.jpg

Now I will go hook it up to 12 v and see what happens.

I was able to split the top heat sink off and lets just say this thing is amazing. I hooked up the wires to my battery and in less than a few seconds the peltier was freezing cold, and the heatsink was getting a little warmer than ambient. I reversed the wires and the heatsink got extremely cold (started frosting) and the peltier got hot enough to burn my finger.

Now I just need to come across a cheap PMD to mount onto this thing. My PMD is still on the IP and I don't want to take it off right now (no sense in fixing it yet if it ain't broke). If anyone knows of a decent place to get a cheap PMD (I don't care if it is used just as long as it works flawlessly) please let me know. Keep in mind I am in Canada so Customs rapes us when we bring things up from the states (unless it is sent as a 'gift'). This is my daily driver and I can't afford to use non-functioning PMDs.

i'd say buy one off ebay. ask the seller if he will declare a gift b4 bidding. and don't buy from joeyeraif.he is in quebec. i sold him one pmd thru ebay. he claims to test them b4hand and as i've seen on the posts these pmd's cannot be tested. the one i sold him never got put on my truck. pump was replaced thru dealer. no i don't know where he gets them but he must buy them thru cheap sellers and theyn rack up the price.

You will get condensation forming but it shouldn't pose a problem as long as it is "drips" downward. You could also add a thermal coupler into your heatsink that controls the time the device is on. Run the positive through the coupler and into a constant 12 volt source and it will turn off power at the coupler cutout temp. If you can find one of those 12 volt fridges you could use the coupler from that.

Also I would definitely place a warning light or guage on it to monitor the heat. If the peltzier fails at least you can save the PMD from burning up.
Just my thought from a new Canadian member, <g>.

I am still looking for a CHEAP PMD so if anyone knows of any please let me know so that I can continue my experiment.

I started with the underhood solution, it's better than factory, but not a permanent one IMO; Out of engine bay IMO is only way to go regardless which method of heat sink you use.

I too would agree, I had one of those expensive coolers mounted on the firewall (as recommended by the seller) and it went down within 9 months. Didn't think about the heat after the engine was off...that dude gets hot and stays hot. Read the posts about moving her outside. Extended the harness and attached the PMD cooler to the backside of the front bumper and it is NEVER hot now. Makes sense to me and was easy to do!!! :cool2:

Makes sense to me and was easy to do!!! :cool2:

And SIMPLE

I just got off the phone with DSG looking for a PMD extension harness. HOLY FCensored! They want over $100 for a 3 foot extension.

I plan on mounting the PMD onto the peltier junction in the cab of my truck so I will need at least 5 feet of extra harness.

What have you guys that have relocated to under the bumper done to extend the harness??? Don't tell me you spent $100 for a $2 connector :p:

I do have an extra 'stock' harness. Can I cut it in half and splice in? What gauge of wiring should I use so that I don't lose any power due to resistance (5 foot harness)? Do I have to use a 'gel pack heat transfer pad' or will some kind of electric grease do the trick (the junction pad is perfectly flat)?

I know that it may not be much consolation, but Kennedy sells a 6 ft extension for $90.00 US...

http://www.kennedydiesel.com/detail.cfm?ID=134

I have used a pelletier device when overclocking my computer using a waterblock/pelletier/Athlon CPU

In order for the pelletier to have maximum efficacy, you need to use a potted one, and have a heatsink attatched to the 'hot side of the pelletier. Cool side down on your PMD. a 227W pelt will be enough to cool your PMD BUT YOU MUST use an appropriate sized heatsink on the pelt with heatsink compound (artic silver) on each side (pmd and H/S)
The a 12V 80 or 120mm fan to remove the heat generated by the pelt' heatsink (TEC)

There is also an issue of condensation between the cooled medium and the heatsink. You may use silicone around the entire layer to minimize the condensation happening on the cold side of the pelt (TEC)

If you go to an overclockers website you will find more exact details there.
J

Dang Juice! Overclock the Athlon, overclock the Dmax, overclock the turbos.. hahahhahah.

Dang Juice! Overclock the Athlon, overclock the Dmax, overclock the turbos.. hahahhahah.

Busted!;)

I have used a pelletier device when overclocking my computer using a waterblock/pelletier/Athlon CPU

In order for the pelletier to have maximum efficacy, you need to use a potted one, and have a heatsink attatched to the 'hot side of the pelletier. Cool side down on your PMD. a 227W pelt will be enough to cool your PMD BUT YOU MUST use an appropriate sized heatsink on the pelt with heatsink compound (artic silver) on each side (pmd and H/S)
The a 12V 80 or 120mm fan to remove the heat generated by the pelt' heatsink (TEC)

There is also an issue of condensation between the cooled medium and the heatsink. You may use silicone around the entire layer to minimize the condensation happening on the cold side of the pelt (TEC)

If you go to an overclockers website you will find more exact details there.
J

It has a large heatsink on the 'hot side'.

Where can I get the heatsink compound you are talking about (computer store I guess)?

I mounted the peltier in the cab, and I am going to wire it up tomorrow. I have a PMD but it is a 'known bad' PMD. I will try the 'loosen/tighten' fix but I still need to know how to extend the harnes 6 feet without losing functionality.

It has a large heatsink on the 'hot side'.

Where can I get the heatsink compound you are talking about (computer store I guess)?

I mounted the peltier in the cab, and I am going to wire it up tomorrow. I have a PMD but it is a 'known bad' PMD. I will try the 'loosen/tighten' fix but I still need to know how to extend the harnes 6 feet without losing functionality.

Computer store. The best stuff is either Artic Silver or Artic Alumina.
1 Tube is 20.00 but goes a long way as you only apply a thin layer.

http://www.arcticsilver.com/as5.htm

Thanks

Can someone post pics of a PMD harness they have extended? Is there a parts store anywhere that carries the correct weatherpack connectors I need (I haven't found any)?

I love having conversations with myself...lol.

I have the peltier mounted in the cab of the truck with my spare PMD mounted to the peltier (cold side).

I just wired it up, and within seconds of the ignition being turned on, the PMD is extremely cold, and the heatsink is quite warm. The PMD is not functional yet (still trying to find a female weatherpak that will mate up with the male end). I'll see if my buddy at Chev will let me see what the techs have in the back...

So in short: a) the peltier is mounted under the dash in the cab, b) the peltier is hooked up to an ignition source, c) the PMD is mounted to the cold side of the junction

I still need to: a) get the correct heatsink compound, b) make a harness extension out my spare harness

I bought the heatsink compound ($5) and that alone made an even bigger difference in the temp of the PMD. I realize that the PMD is not connected and therefore is not producing any heat, but the fact that this junction can turn the PMD freezing cold, and the heatsink on the other side hot enough to burn my hand tells me I might be on to something.

I have the parts I need for my extension harness on order, and I should have it built shortly.

wher'd ya git the extension parts.

I bought the heatsink compound ($5) and that alone made an even bigger difference in the temp of the PMD. I realize that the PMD is not connected and therefore is not producing any heat, but the fact that this junction can turn the PMD freezing cold, and the heatsink on the other side hot enough to burn my hand tells me I might be on to something.

I have the parts I need for my extension harness on order, and I should have it built shortly.

It might be wise to get an 120mm DC computer fan controlled by a thermistor to run when the truck has no airflow across the pelletier's heatsink. When temps get too high a pelt will melt down and short out (been there done that on my home computer system)

FYI

edzzed - I ordered the parts from Saskatoon Truck Line (Pico Canada). I am in Saskatoon. The parts are coming from out your way (Burnaby ???).

Got Juice?- I have thought about that and I will most likely put a small CPU fan on a time delay on the heatsink once I get the rest of the system put together - thanks for the input.

Kennedy has those ext harness's for sale

Got Juice?- I have thought about that and I will most likely put a small CPU fan on a time delay on the heatsink once I get the rest of the system put together - thanks for the input.

I thought you might.

What part of stubble jumpin country are ya from?

I have some relatives in Saskatoon, Regina, Lloydminister, Onion Lake, Paradise Valley, Wakaw and a few other places:D

edzzed - I ordered the parts from Saskatoon Truck Line (Pico Canada). I am in Saskatoon. The parts are coming from out your way (Burnaby)

dang that's close to me. like 12 miles at most. i'm going down there tomorrow. thanx ed

I have some relatives in Saskatoon, Regina, Lloydminister, Onion Lake, Paradise Valley, Wakaw and a few other places:D

Saskatoon, my family farms outside of Langham.

dang that's close to me. like 12 miles at most. i'm going down there tomorrow. thanx ed

I was told to order part #s 5670 and 5671. I will find out in a week if they are correct.