Why does water flow out of the PVC pipe from the indoor unit?
The air around us is made up of several components, Nitrogen, Oxygen, other elements but importantly “Water Vapor”. At times we “see” water vapor in the form of clouds or fog, it is always present in varying amounts and is “weather” driven. In Florida we are “dryer” in winter and very humid in summer. The PVC pipe is a place for the excess water to go.
The job of the air conditioner (Heat Pump) system is to not only lower temperature but to dehumidify the air, the combination of these two is the “Comfort Conditions” we experience.
The water flowing out the pipe is the water vapor that the system condensed from the indoor atmosphere into liquid water and is discharged out via the PVC pipe (or other piping material) to be disposed of outside the “indoor comfort environment”. The quantity of this water is weather driven, more humidity – more water condensing, and as this pipe is “always wet” mold, algae and fungus like to grow in it therefore a biocide such as chlorine bleach or vinegar added to this water will keep the drain from “backing up”. ¼ to ½ cup of bleach, once per month will aid in keeping the drain line flowing smoothly.