Introduction: My Diy Peltier Cooler! - DECOMMISSIONED

Picture of My Diy Peltier Cooler! - DECOMMISSIONED

I always wanted a means to keep groceries cool enough in my car without having to rush home to my refrigerator. I decided to use an old Peltier heat exchanger I made a few years ago.

I sandwiched the Peltier between two aluminum heat sinks. The bigger one being the hot side. I used plain off the shelf steel epoxy to stick the heatsinks onto the Peltier and it has held firm for a few years plus the heat transfer capability is great!

Step 1: Modding a Cooler.

Picture of Modding a Cooler.

Using a cheap 24 quart cooler, I went about modifying it to fit the heatsinks.

Step 2: Making an Opening.

Picture of Making an Opening.

I used the cold heatsink to mark the lid of the cooler. Next I cut a rectangular opening to be able to slot the heatsink in.

Step 3: Securing the Peltier Assembly Onto the Lid.

Picture of Securing the Peltier Assembly Onto the Lid.

I used a long bolt and nuts to clamp the cold heatsink and thereby hold the entire assembly onto the lid.

Step 4: Installing a Recirculation Fan.

Picture of Installing a Recirculation Fan.

Using a spare blower fan, I secured it to the underside of the cold heatsink fins. This will keep the cold air in circulation over the groceries.

Step 5: Temperature Measurement.

Picture of Temperature Measurement.

I had a spare digital thermometer that I siliconed onto the lid. Its sensor I stuck on the underside of the lid. Now I can easily tell the inner and outer temperatures to gauge the performance of my chiller.

Step 6: Getting Power to the Chiller.

Picture of Getting Power to the Chiller.

For 12 volt power I used the standard car socket plug to give me the 5 Amps my setup requires. The power chord to the chiller I secured to the lid.

The power chord is split into 2 parts so I can power it from a wall adapter or the car 12 volt supply.

I actually used a 5 volt adapter to keep cold food chilled if I'm powering it from household voltage. At 8 watts I can safely keep cold foods cold! Once already cold food is in the cooler, that 5 volt adapter will be sufficient to maintain the coolness. Peltier devices are actually more efficient when powered from low voltages but they won't move as much heat.

Step 7: Testing and Completion!

Picture of Testing and Completion!

My low cost diy Peltier chiller cooler works as per my expectations. I'm happy with the 2 hours involved in Making this neat little chiller.

I will keep it in my car so anytime I get groceries or medication, I don't have to worry about it getting warm!

I hope this instructable has been interesting to you folks.

Update: 4 hours later.
The steel epoxy gave out after 3 years of holding the setup together.



After the failure of the expoxy with the first Peltier, I used another one I had in storage. I secured it with cable ties to the lid and it works well enough but not as good as the original heat exchanger. The plus side is it uses half the power as the original.

Step 9: Revamp!

Picture of Revamp!

I have since upgraded the cooler with this updated instructable:

Check it out!


zakariaa21 (author)2016-09-19

yes nice idea

franks188 (author)zakariaa212017-01-23

it´s very nice

rockhammer53 (author)2016-03-12

These peltier devices have been around since the 80's, Igloo and others have been producing commercial units for over a decade. The downside..these are CURRENT HOGS. We abandoned these in the medical electronics field years age for that fact, regular refrigeration systems are more economical. and efficient....they are fun to play with however. OLD technology BTW.

I totally agree!

sea.king.1069 (author)2016-03-12

you've overthunk yourself. buy a couple of blue freezer packs, freeze them hard and pop them in the cooler on your way to the store. your food will stay nice and chilled with no issues and no PIA McGivering things about.

ByronM (author)2016-03-06

Air to goodies heat transfer is usually very bad. If water is the heat transfer mechanism it works much better. Have tried to cool cans from ambient temperature and it's almost impossible. Some water can help for sure .

david.roseman (author)ByronM2016-03-07

So then how do refrigerators work? They don't use water to move the cooling medium around, they use air and fans.

correct but compressor type refrigeration systems have a far higher EER than bogus peltiers.

Mjtrinihobby (author)ByronM2016-03-06

I fully agree, I did a water diy chiller with Peltier that worked fairly well.

nealalan (author)2016-03-07

Any experimentation with using this with a solar panel? Any thoughts from EE's out there, how this would do at the beach on a 90F day, in the shade with a solar panel in the sun?

Mjtrinihobby (author)nealalan2016-03-07

A 100W panel would be the minimum rating needed and to me that size is just too large to walk around with. Nevertheless it would work but to me it is not practical. If one of those true compressor type 12V portable freezers were used then that would be an extremely good solar cooling combination. Problem is those types are damn expensive (at least 350USD) expensive it may get stolen if left unattended on the beach.

andrewty (author)2016-03-07

Farnell sell a 30W Peltier for £21.50 plus V.A.T.

That's 86p/W

Mjtrinihobby (author)andrewty2016-03-07

that is way too expensive. I pay 2.35USD for 60Watt modules.

Quester-59 (author)2016-03-06

Great Idea, Too bad Igloo beat you to the Patton Office.

However, A Better Idea or improvement could net you millions.

Mjtrinihobby (author)Quester-592016-03-07

I got some other projects I wanna patent. Lol.

Quester-59 (author)2016-03-06

By the way, Adding Silicon For your gaskets & Spacers will help prevent any plastic from melting.

Mjtrinihobby (author)Quester-592016-03-07

So true.

onesimpleidea (author)2016-03-06

@Mjtrinihobby Nice project. When you got to the testing phase, I was hoping to see some information about your results, photos of comparative temperature readings, etc. Didn't see any of that. Can you add some in comments?

I got 10 Celsius below ambient with the original Peltier but the replacement is not as good. I want to remake it with heatpipe heatsink to be a little more efficient.

mchazlitt (author)2016-03-06

Maybe another small fan inside for circulation, since you have reduced the power consumption.

Mjtrinihobby (author)mchazlitt2016-03-06

Good idea.

BurgersBytes (author)2016-03-06

Since both heat sinks are larger than the Peltier, why not just bolt them together?

Also use heat sink compound on both sides to transfer the heat better!

joelparks (author)BurgersBytes2016-03-06

one side is hot and the other side is cold. So you wouldn't want to use anything that conducts heat. Sure, there are plastic bolts out there, some folks may even have some left over from a replacement toilet seat. But it's still a thermal path that would reduce efficiency somewhat

Mjtrinihobby (author)joelparks2016-03-06


AviationMetalSmith (author)2016-03-06

You should try doing this with a hot-melt glue gun, instead of silicone caulk, or screws, or whatever...

Hot glue won't Hold.

hippiechk (author)2016-03-06

What are you getting for chilling power? As in, how many degrees below ambient? Can this hold the 4°C internal temp safe for dairy storage for a few hours? Nice idea!!

Mjtrinihobby (author)hippiechk2016-03-06

Thank but this definitely cannot be used for diary. Far too inefficient.

RobTurrentine (author)2016-03-06

My only problem is that I have a Subaru Outback and the power is off when the car isn't running. Otherwise, cool (HAHA) idea.

Same with my car.

DonG36 (author)RobTurrentine2016-03-06

Guess the easiest thing would be to buy a different car hehehehe.

billbillt (author)RobTurrentine2016-03-06

This would be an easy fix... Run two wires from the battery to a lighter socket plug...

boostme (author)2016-03-06

Where, how did you obtain the Peltier?

TimothyJ999 (author)boostme2016-03-06

Really? Sigh--ok.

Ebay has 12V, 60 watt Peltier coolers for about $2. Amazon has them too. So does Banggood. So do Tetech, Sparkfun, Adafruit, Marlow, and Z-max.

ACM2 (author)TimothyJ9992016-03-06

The Ultimate question, what is Peltier???

pnosko (author)ACM22016-03-06

A prerequisite question would be "what is Google." ;)

Sam Grove (author)ACM22016-03-06

A Peltier (pel-tee-ay) device, when a current is passed through it, will transfer thermal energy from one side to the other. It is used in solid state cooling devices.

Mjtrinihobby (author)TimothyJ9992016-03-06

Great reply!

bobstuart (author)2016-03-06

I've got two peltier junctions. They are still neatly installed in the 12v cooler/heater units they were sold in, and then re-sold to me for $5 & $10 at garage sales.

ironsmiter (author)2016-02-15

NM, My guess WAS between 12.6 and 13.2.

Then I went back and looked at your last picture.

Might want to get your alternator checked!

But of course, it is NOW running at zero volts, since it has been decomissioned.

Mjtrinihobby (author)ironsmiter2016-02-15

All the pics were taken when the cooler was powered from my bench power supply. It failed in the car. What a heart breaker.

ThomasK19 (author)Mjtrinihobby2016-02-16

Why did it fail? Your car battery should provide enough wattage at 12.8V. And this does not look like it's very sensitive to voltage variations.

Mjtrinihobby (author)ThomasK192016-02-16

It was mechanical failure...the steel epoxy just came apart! Arghhh! I have a spare Peltier heat exchanger that I used to restore usage this morning. I will update this instructable and of course delete these comments about this annoying failure.

JesusG33k (author)2016-02-14

The peltier is running at 12V right?

About This Instructable




Bio: As of April 2017 I have decided to no longer post on instructables. The fact that several of my published works have been removed without ... More »
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