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Hello there! I'm Dr. Vinifera, or "Vinny" for short. Ask me your toughest wine questions, from the technical aspects of winemaking to the fine points of etiquette. I hope you find my answers educational and even amusing. Looking for a particular answer? Check my archive and my FAQs.

Dear Dr. Vinny,

Is there a difference between compressor and thermoelectric wine coolers as far as humidity levels?

—Scott T., Australia

Dear Scott,

Most wine coolers have compressors, which work just like food refrigerators. With a compressor, the refrigerant’s molecules are compressed together, creating a heated vapor, which travels through a condenser, then undergoes a flash evaporation, turning it cold. Then a fan blows air across the coils, which is where the cooler’s cool air comes from.

Thermoelectric cooling systems have fewer moving parts. If you stayed awake during science class, you may remember that thermoelectric coolers use the Peltier effect, which I can only describe without my brain hurting by saying that the temperature difference is created by an electrical current. Thermoelectric systems don’t add cold in as much as they take heat out. Since they don’t have a compressor, thermoelectric coolers are known for being vibration-free, quieter and more energy efficient. But they don’t typically work as well in warm areas or in places where the temperature fluctuates widely (when there is more heat to take out), and they tend to be made in smaller units, where they’re most effective.

Humidity sometimes comes up in the discussion about compressors, because compressors can create condensation and, whoa, does that mean it’s taking water out of the air? But condensation on a compressor isn’t so much a factor of the compressor sucking all the moisture out of the air as it is about the temperature difference between the water vapor and the surface it’s interacting with. After all, when I pull a cold bottle of wine out into a warm room, if some condensation forms on the bottle, it doesn’t mean the room is suddenly less humid.

That’s a long way of me saying no, I don’t believe there is a particular difference in humidity levels between the two cooling techniques. There are benefits to both systems, and you just need to figure out what works best for you.

—Dr. Vinny

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