Peltier elements in cool terrariums

[King of diamonds]

As you may be aware, a peltier element is a small electronic component that grows cold when current is applied. This is the cooling system found in most travel fridges and small wine fridges.

They aren't very powerful but they seem ideal for lowering temperature by a few degrees and are very cheap ($3.95 shipped on ebay), just throw on a pc fan.

I have seen a number of users storing cool growing plants in wine fridges but I am wondering if it is common to buy the elements themselves.


Sorry if this is a stupid question, I'm fairly new and was directed here from the beginner board.

[Ray]

I think one of the difficulties is heat transfer from the air to the Peltier cooler. A terrarium is not as well sealed as a fridge or wine cooler, so the cooler will need to do more work.

I suspect that a finned aluminum "heat sink", with fan drawing the air through the fins would work.

[King of diamonds]

My current set up involves a 13 gal tank and two peltier elements with cpu heat sinks and fans. They only cool it about 4 degress below ambient but they are cheap enough to throw lots in.

Mine has lots of air movement from the two fans so it would probably not work as well in other tanks without fans.

[FairyInTheFlowers]

Originally Posted by Ray

I suspect that a finned aluminum "heat sink", with fan drawing the air through the fins would work.

This sounds quite interesting, Ray, would you mind explaining further? I am considering building a plant stand in my basement for some cool growers, but the in-floor heating might pose a problem in the winter, so I am interested in any way possible to cool it down.

[King of diamonds]

For a cooler there needs to be as much air traveling across the element as posible. this means that more Ir.is.cooled.at once, thus cooling the tank more.effectivly. a heat sink is a series of metal plates thate effectivly increase the surface area of the element by a large amount. combined with a fan to draw air past this makes sure the maximum amount of air is cooled.

heatsinks are common on many electronic devices, usually as a method of cooling, the most common source for sinks of this size are computor processors. they often have large heat sinks and these can be bought easily and very cheaply on old computors. your local recycling center will likely.give them to you for free or for a few dollers each. the sink is passive. Computer fans are also ideal as they are very cheap and small enough to fit on to the front.

Little elctronic experience is required, just hook the fans up to the same power supply that the elements are running off (an old computor power supply works great for this too)


hope this answers your question. sorry for any spelling errors, posting from my phone

[Wjs2nd]

Heat-sinks draw heat threw them to their tips. Attach a heat-sink to something you want to cool. Blowing air over the tips of the heat-sink helps the heat dissipate faster.
Basic heat-sink TO-220/TO-202 Aluminum Heat Sink : Heat Sinks | RadioShack.com

[keithrs]

Lol.... I was looking at peltier cooler today on my break.. As I too am looking for a cheap n reliable way to cool a fairly large terrarium. I had found a blog from a gent that built a terrarium that needed to cool down to 50 f at night. He used two 90.2 w peltier coolers off ebay for $15 shipped with heat sinks of old CPU's. Also used a CPU fan to blow the cooled air into the terrarium. The terrarium was about the size of a small fridge and cooled it from 75 down to 45 f in 20 min.

[keithrs]

I did some more research and found cpu nuts use them for cooling there computers. They combine water cooling tech with peltier cooler tech. A lot of good info out there.

[Goods14]

Keith, please post where you've found this. I've seen CP people use the components of a window unit to cool a tank and also the computer radiators.

Here's a link for the radiator idea: My cooling unit - Carnivorous Plants UK

There are a few other interesting threads on that site if you do a little digging.

[keithrs]

This site had some of the best info I've found.

tecpeltier