Should My Ductless Mini Split Outdoor Unit Have Ice on It?

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A ductless heating and cooling system is actually a type of heat pump. The principle difference between it and a standard central heat pump is that a ductless system uses mini air handlers to distribute heating/cooling indoors, rather than a single indoor unit attached to ductwork. In all other ways, it operates as a heat pump and can suffer from similar malfunctions. One of these is the development of excess ice on the outdoor unit during the winter.

Why Ice May Appear on the Outdoor Cabinet

While in heating mode, a heat pump uses outdoor refrigerant coils to siphon the available thermal energy from the air. As it does this, it also draws water vapor, which condenses along with the coil. If the temperature outdoors is below the dew point and the freezing point, the water will freeze on the coil. This usually occurs in situations where the outdoor temperature is below 40°F and the relative humidity is high, which is a common occurrence in Georgia.

Should You Worry About This?

Most of the time, frost appearing on an outdoor heat pump cabinet is not an issue. In fact, the manufacturers expect it and build defrost controls into the system. Periodically, the heat pump will reverse the refrigerant flow to warm the coils and melt off the frost.

But malfunctions can still occur. The defrost controls can break, allowing frost to keep building up. The ice will start to block heat absorption, which will limit the heat pump’s ability to warm your home. Another possible cause for the frost is that the heat pump has lost refrigerant through a leak. Refrigerant loss can cause catastrophic damage to the heat pump’s system and needs to be repaired immediately.

So if the ice on your ductless mini-split heat pump stays for longer than two hours, call for technicians to see what is wrong and fix it. Premier Indoor Comfort Systems LLC offers heating repair service in Marietta, GA.