How Thermoelectric Wine Coolers Work
If you've been shopping for a wine cooler or wine chiller to house your growing collection of fine wines, you have probably discovered two distinct types: compressor and thermoelectric. While these coolers may look the same on the outside, there is a world of difference in how they operate. If you're going to invest a few hundred dollars or more in an appliance for your home, it's a good idea to know about the technology you're paying for.
A compressor wine cooler operates just like the refrigerator in your kitchen. A liquid refrigerant (Freon) circulates through a compressor system that produces cold air inside the refrigerator and expels hot air externally. The advantage of this kind of this cooling is that it can reach very cold temperatures - our AWC-330E units can cool down to 39°F, which is great not only for chilling white wines but also for keeping other beverages and food at safe storage temps. But because there are a lot of moving parts in this system, it can be noisy - just like the refrigerator in your kitchen. Not to mention that refrigerants present certain ecological concerns by introducing CFCs and HCFC-s into the environment.
The Principles of Thermoelectric Cooling
In contrast, thermoelectric coolers are environmentally safe, since they don't have any hazardous materials fueling the cooling process. Thermoelectric cooling relies on the Peltier effect, named for the 19th century scientist who discovered it. When an electric charge is sent through two joined pieces of metal it creates a heat flux, and heat is transferred from one side of the device to the other. One side gets hot and the other side gets cold. The core cooling device (called a heat pump) is small, not much more than an inch square, with semiconductor wires embedded between the two ceramic plates:
Because it is small and has no moving parts, a thermoelectric heat pump operates silently, which is a big advantage over the usual sort of refrigerator that uses vapor compression to provide cooling.
In a wine cooler, the heat pump is combined with a heat sink - a large, passive component made up of stacks of aluminum fins that allow heat to dissipate efficiently. The cold side of the combined heat pump-heat sink is inserted into the interior of the wine cooler, and the hot side extends out the back of the compartment (though protected by a back panel on the unit).
Fans attached to each side of the heat sink improve the unit's ventilation, circulating the cool air inside more evenly and expelling heat outside more effectively.
There are some important limitations to the effectiveness of a thermoelectric cooler that you should be aware of before you buy one.
- They don't get as cold as a compressor cooler. On average, most thermoelectric coolers won't cool below 50°F, though you will find some (like our dual zone AW-210ED) that can go as low as 44°F.
- They don't work when it's too hot. Unlike a refrigerator, a thermoelectric cooler doesn't produce cold air. What it does is remove the heat from inside the cooler compartment. This means that when the temperature is too hot (over 80°F) it will have trouble removing enough heat to keep the temperature at the ideal wine storage level of 55°F.
- They don't work when it's too cold. There is no mechanism to add heat into wine cooler, so when the ambient temperature drops below 50°F, the temperature inside will drop as well, affecting the storage conditions of your wine.
What this means is that before you select a thermoelectric wine cooler, be sure to check the manufacturer's specifications. Make sure it has a thermostat range that matches your wine storage preferences, and be sure to follow the recommendations for ambient temperatures. These coolers are meant to be used indoors in controlled environments, not in garages, sheds or outside.
Thermoelectric Cooler Advantages
As has already been noted, one of the big advantages of thermoelectric wine coolers versus compressor wine coolers is that they are environmentally safe, because they don't use refrigerants that have been linked to ozone depletion. When operating under proper conditions, they also use less electricity to operate than a compressor system, which benefits both the environment and your wallet.
They are also much quieter than regular refrigerators, since the only moving parts are the small internal fans. This means they won't intrude on your indoor environment - or keep you from enjoying your favorite show on TV!
Another positive side-effect of no moving parts is that a thermoelectric wine cooler is almost virtually vibration free. This means your prized wines won't be continually upset, and the natural sedimentation process that occurs as wine ages won't be disturbed. In other words, your wine will taste better when you're ready to drink it.
Also improving the quality of your wine is the more consistent interior temperature. While a compressor cooler might fluctuate as much 10 degrees from top to bottom, a thermoelectric cooler maintains a more even temperature throughout the cooler.
Getting the Most out of Your Thermoelectric Wine Cooler
To get the best performance from your thermoelectric wine cooler, keep the following guidelines in mind:
- Make sure you keep it where the ambient temperature is in the recommended range of 50° to 80°F.
- Leave at least 5" of clearance around the cooler (for freestanding units) to allow proper ventilation. If there is not enough ventilation to disperse heat effectively, the heat pump will overheat and burn out. This is the number one reason why thermoelectric wine coolers fail!
- For the above reason, do not ever install a freestanding thermoelectric wine cooler into your cabinetry. Units that are meant to be built-in have special ventilation mechanisms visible on the front of the unit, just like your refrigerator.
- If the wine cooler seems to be making too much noise, make sure it is positioned on a level surface and evenly balanced. NewAir thermoelectric wine coolers have adjustable leveling feet that let you compensate for uneven flooring.
- If leveling the cooler does not alleviate the noise problem, one of the fans in the unit might be obstructed. See if you can spot anything on or around the fans that might be making it spin noisily.
If you have other problems with your wine cooler, check the manual for troubleshooting advice, or contact your dealer for assistance.