I was pleasantly surprised that the RC-WC52 is absolutely silent. Unlike other Peltier coolers, it does not have a fan, but rather large waste heat pipes on the back. I filled it, set it to 13 degrees (with the outside temperature at 26 degrees) and also placed an independent thermometer on the side of the door. After about 3 hours of cooling, it showed 12.4 degrees, then it fluctuated between 12.8 and 13.6 degrees for 24 hours and then settled at a measured 13.0 +-0.2 degrees. It sometimes shows 12 degrees on the device's internal display, then 13 again. Everything is fine - it cools well and makes no sound! I am very happy with the device, much better than my previous wine cooler.