What is the difference between using an external drain vs. a boil-off coil inside the unit?
All cooling units, especially during hot humid weather, will periodically cool the air below the dew point of the cellar thereby removing excess moisture and preventing too high a humidity. The moisture forms on the cold cooling coil surface and drips into a drain pan. It is then either piped to a drain outside the unit or into the condenser section of the unit where it comes in contact with hot gas tubing from the compressor and is boiled off. There are three problems with this. The first is the corrosion that occurs on the hot gas tubing, which will cause refrigerant leaks. The second is that this moisture is then just added back into the air-stream of the condenser exhaust where it can find its way easily back into the cellar. The third and potentially the most serious problem, is that this warm moist air being discharged into a room may cause mold and mildew to form on cool surfaces. The most reliable and least costly way to get rid of the excess moisture is to pipe it to a drain w
