If the freezer door of your new Energy Star rated refrigerator feels warm, it is likely due to a normal operation known as an "anti-sweat" or "mullion" heater. This feature is designed to prevent condensation and frost buildup on the outer surface of the freezer door, especially in high humidity environments.
Here's how it works:
Humidity Control: When the surrounding air is humid, moisture can condense on the cold surface of the freezer door. This condensation can lead to water droplets forming on the door or even frost buildup, which may affect the refrigerator's performance and appearance.
Mullion Heater: To counteract this issue, some refrigerators are equipped with a mullion heater. The mullion is the vertical strip that separates the freezer and refrigerator compartments. The heater warms the mullion's surface slightly, reducing the temperature difference between the inside and outside of the door.
Preventing Condensation: By raising the temperature of the mullion, the heater prevents the outer surface of the freezer door from becoming cold enough to cause significant condensation. As a result, the door feels warm to the touch.
Energy Efficiency: Even though the mullion heater consumes a small amount of energy, most Energy Star rated refrigerators are designed to be highly efficient, so the energy usage is minimal compared to the overall savings from reduced energy consumption.
If you notice that the entire freezer or refrigerator compartment is excessively warm or if you observe other performance issues, it could be a sign of a malfunction. In such cases, it is advisable to check the refrigerator's settings, ensure proper ventilation around the appliance, and consider contacting the manufacturer's customer support for assistance or warranty service.