Thermoelectric cooling

[Connie Star]

Originally Posted by johnblagg

Actually I have played around with peltier chips a bit and they could be used for this very easily ...and without opening the cabinet or introducing outside air.....not sure how effective one would be.BUT when stacked they can get down to cyrogenic temps though

What are Peltier chips?

[PaphMadMan]

Originally Posted by Connie Star

What are Peltier chips?

When you run a DC electrical current through a point where 2 different metals meet, one side gets hot and the other side gets cold. This is called the Peltier effect. A Peltier chip looks like a small ceramic tile with wires sticking out, contains a large area of contact between different metals, and acts as a heat pump by using the Peltier effect. Essentially it can be used as a tiny air conditioner with no moving parts except a couple fans.

[tropterrarium]

I have used the ice probe (e.g. IceProbe Thermoelectric Aquarium Chiller (Coolworks)) to cool about 1-2 liters of water for my swamp cooler in my 90 gal terrarium. The cooling power is WAY too feeble, and the unit stopped working after a day. So I switched to a proper 1/15 HP aquarium chiller. 200 BTU is puny, I would estimate you could cool a gerkin jar with it, but not much more.

I also loved the idea, and a Peltier device is kind of tech-geeky, but there are limits to those devices.

[s1214215]

I believe the temp drop of peltiers is 5 degree below ambient temp..

I use a radiator and aquarium chiller set up and I maintain 23 celcius, up to 26c when it s really hot.

Brett

[johnblagg]

Originally Posted by s1214215

I believe the temp drop of peltiers is 5 degree below ambient temp..

I use a radiator and aquarium chiller set up and I maintain 23 celcius, up to 26c when it s really hot.

Brett

actually it is more along the range of 30 degrees below ambient the igloo coolers for example have that degree of cooling power...and when stacked peltier chips can in fact get all the way down to cyrogenic temperatures and are used for that application too.

they do make solid state a/c units in fact now for lab use

[Tindomul]

Are you able to control the temp precisely with this product?

[tropterrarium]

Originally Posted by Tindomul

Are you able to control the temp precisely with this product?

For precise (+/- 1-2F) control for any heating/cooling you need some sort of feedback with a temperature (and/or humidity) probe. There is Ecozone that is advertising here, I'm waiting for the herpkeeper to be released by Digitalaquatics. The latter seems more flexible, as you can have more than four outlets on one controller box. I will get the Herpkeeper as soon as it is out, and can post a initial impression here if folks are interested.

For the iceprobe, there is a dedicated temperature probe available, but as the unit went bust immediately, I did not go that route. So it depends on the particular chiller you're talking about. Also important to make the distinction on water coolers on a cooler temperature control (keeps the coolant at a particular temperature) and terrarium temperature control. Depending on room temperature, you need more or less cooling (or heating) even if the coolant/heater has a set temperature. There are some aquarium chillers that have optional temperature probe for the enclosure; not sure they work in air or just in water, though.

I think the more general habitat controllers (like Ecozone or Herpkeeper) are more flexible, as one can run several accessories from different manufacturers through it.

[PaphMadMan]

Originally Posted by Tindomul

Are you able to control the temp precisely with this product?

The product I linked to has a built in temperature control which should be precise within the unit's ability to compensate for heat sources like lights, etc. That would give a constant temperature. To get a night-time temperature drop another controller would be necessary, but should be quite precise.

[Connie Star]

Originally Posted by PaphMadMan

When you run a DC electrical current through a point where 2 different metals meet, one side gets hot and the other side gets cold. This is called the Peltier effect. A Peltier chip looks like a small ceramic tile with wires sticking out, contains a large area of contact between different metals, and acts as a heat pump by using the Peltier effect. Essentially it can be used as a tiny air conditioner with no moving parts except a couple fans.

That's interesting. It sounds like they aren't very practical from the ongoing discussion.

[johnblagg]

well That depends on space considerations and such realy....they actualy are used in a lot of lab equipment as they can be stacked and go down to cyrogenic temps ...they use them for cooling in computers some also...I was looking them up yesterday and they do have airconditioning units built with them now also