evaporation, improving overall efficiency. Disposal Products using condensation technology have traditionally used a cold surface where humidity in warm air is condensed. Today, warm condensation technology, based on the concept of over-saturated steam inside a closed environment, makes it possible to dehumidify air at sub-zero temperatures. This is a very energy-efficient technology and equally efficient in all temperatures. Most portable dehumidifiers are equipped with a condensate collection receptacle, typically with a float sensor that detects when the collection vessel is full, to shut off the dehumidifier and prevent an overflow of collected water. In a warm humid environment, these buckets will generally fill with water in 8–12 hours, and may need to be manually emptied and replaced several times per day to ensure continued operation. Many portable dehumidifiers can also be adapted to connect the condensate drip output directly to a drain via a hose. Some dehumidifier models can tie into plumbing drains or use a built-in water pump to empty themselves as they collect moisture. Alternatively, a separate condensate pump may be used to move collected water to a disposal location, when gravity drainage is not possible. Central air conditioning units typically need to be connected to a drain, because frequent manual emptying of multiple containers of condensate water extracted by such systems is impractical. If the condensate water is directed into the sewer system, it should be suitably trapped to prevent septic odors and sewer gases from entering the building. The condensate should not be directed into a septic system of a house, because it does not need special treatment as effluent. When the height of the air handler (containing the evaporator) is above the level of the surface drains used for rainwater, the condensate drain lines can often be routed into them. Air handlers located below grade level, e.g. the basement of a house, may need to use a condensate pump to lift the water to a surface drain. Potability Generally, dehumidifier water is considered a rather clean kind of greywater: not suitable for drinking, but acceptable for watering plants, though not garden vegetables. The health concerns are: The water contains trace metals from the heat exchanger, such as copper and aluminum, or zinc from galvanized steel supporting the frame and drain pan. Condensate would only be exposed to tin-lead solder in copper drain pipe, but the lead content is particularly dangerous. Trace metals may pose a