Portable USB powered liquid heater/cooler COMET Cryothermic Coaster review

COMET Cryothermic CoasterThe COMET Cryothermic Coaster is a little disk that plugs into your USB port via a standard USB cable and is aimed at people wanting to keep their beverages warm or cool. While the warming is as long as the unit has power, the cooling effects are listed at only 15 minutes of cool, so I decided to test that with some Kirkland Signature Infant Formula.

I mainly did this because ITmama Kim was mentioning the virtues of having a fridge nearby to store formula that picky Baby M decides she doesn’t want to drink right after you make it, and I happened to have one of these that the Dhama Innovations company gave me a while back that was just sitting on my desk.

COMET Cryothermic Coaster cooling

I made the assumption that the device is capable of cooling a 12 oz can for about 15 minutes before the ambient temperature overwhelms the cooling assist of the 12 ounces of soda and wondered what smaller amounts such as what a baby might drink would handle.

So, to those ends I took 2 ounces of formula fresh from the fridge after being ignored by baby and did a very unscientific test using a USB port on theITbaby’s server to see if the power of awesome could keep a small amount of baby formula chilled in an AVENT bottle.

The way the COMET Cryothermic Coaster works is like any basic air conditioner does, it moves heat from one place to another. Unlike air home conditioners, it doesn’t have a compressor or use fluids such as Freon to do this, it just pushed the heat from the top down out the bottom, which is slightly elevated and hopefully has some ventilation, because it will get warm.

After 15 minutes in a rather cool room, the formula bottle had started to bead sweat on the outside of the bottle, and the disk was still cold on the top and hot on the bottom. The sheer heat that had pushed down into the server’s chassis was enough to feel from a few inches.

After 30 minutes, the formula had increased in temperature from what it was in the refrigerator, but seemed to be maintaining a cool disposition. The heat expelled had pooled up underneath the disc, and the cooling disc on top was still as cold as a refrigerated bottle should be.

But the formula wasn’t that cold.

COMET Cryothermic Coaster heating

There’s no question the thing works great to heat up a bottle or keep a drink warm. It does a remarkably good job of keeping coffee warm, or warming cooled milk or formula up. It’s not particularly fast, but it’ll do in a pinch.

Why would you do this?

If you’re at an area where you know you’ll have power but not a fridge, this is useful. A small pocketable USB-powered cooler/heater is a wicked useful device to have when you’re limited on space and need to maximize your baby options.

It’s also an idea if you’ve got limited shelf space and plenty of USB ports available, as can happen.

The problems

On heating, there are none other than it’s better at maintaining than heating, but it gets the job done. On cooling you’re pushing the heat downward and out. This means whatever you have the bottle on is heating up pretty quickly as the heat calories are being pushed downward.

The efficiency of cooling starts to fail as the heat underneath it builds. This can be worked around by moving the thing, but that sort of defeats the purpose I wanted it for.

Heat also rises, and conversely cold falls, so having an ice cube directly underneath the bottle doesn’t help for too long.

My guess is 15 minutes for cooling is about what you can expect and that due to my cool room and ventilated server case I got some more cooling than you would expect to get.


While it’s not the ultimate baby tool, it is something neat to consider at and perhaps there will be another version soon enough that will aim more at cooling, perhaps by having a fake floating ice cube or heat-remover at the top of the drink.

The COMET Cryothermic Coaster is available for $30 from Dhama Innovations

3.5 / 5 stars