A dehumidifier removes excess moisture from the air by pulling humid air over chilled coils, causing condensation. This process collects a significant amount of water that might appear clean and pure. However, the collected water is not safe for human consumption under any circumstances. The dehumidifier mechanism is engineered for air drying, not for producing potable water, introducing contamination risks that make the liquid unsuitable for drinking due to biological and chemical hazards.
The Dehumidification Process and Water Collection
A dehumidifier uses a refrigeration cycle, similar to an air conditioner, to cool a set of coils. As warm, moist air passes over these cold surfaces, water vapor condenses into liquid droplets that drip into a collection bucket. This condensate is initially pure because the evaporation process left behind minerals and salts.
Purity is instantly compromised as the water contacts the machine’s internal components. The water flows over metal coils, plastic tubing, and reservoir walls, none of which are manufactured to food-grade or sterile standards. This contact immediately introduces airborne particulates and trace materials from the appliance itself.
The collected water is often mistakenly compared to commercially distilled water. True distilled water is produced by boiling water into steam and then recondensing it in a completely closed and sterile system, a process that actively removes impurities. A dehumidifier only relies on passive condensation and lacks the high heat sterilization and hermetic collection required for a safe, purified product. Therefore, the dehumidifier water is merely condensate that begins to accumulate contaminants the moment it forms.
Hazards from Biological and Chemical Contaminants
The dehumidifier’s collection tank is an ideal breeding ground for microscopic life, presenting the most immediate biological hazard. The dark, stagnant water and moderate temperature promote the rapid growth of microorganisms like bacteria and mold. These organisms are pulled directly from the ambient air, including Legionella bacteria and various mold spores.
Ingesting water contaminated with these pathogens can lead to gastrointestinal distress, respiratory illness, or other serious infections. Even if the water is clear, it can harbor high concentrations of these invisible biological hazards. The risk is present even in frequently emptied reservoirs, though it increases the longer the water remains standing.
Chemical contamination adds another layer of risk, primarily originating from the appliance’s construction. As the water flows over and sits near the metal components, it can leach trace amounts of heavy metals into the liquid. These metals can include copper from the coils and, potentially, lead from internal solder points, especially in older or damaged units.
The condensed water also captures fine particulate matter from the air, such as dust, pet dander, and Volatile Organic Compounds (VOCs) from household products. Boiling this water, a common purification method, will kill bacteria but will not remove heavy metals or chemical residues. In fact, boiling only concentrates the non-evaporating contaminants, making the remaining water even more dangerous for ingestion.
Safe, Non-Potable Uses for Dehumidifier Water
Since the water is unsafe to drink, it can be repurposed for various non-ingestion household tasks, conserving potable tap water. Due to its low mineral content, a major benefit of the water is its suitability for use in steam irons. Using this water prevents the buildup of limescale within the iron’s heating element, prolonging the appliance’s life.
The collected liquid is effective for general cleaning, such as mopping hard floors or washing windows and cars. Since it lacks dissolved minerals, it tends to leave fewer streaks on glass and polished surfaces. Another practical use is flushing toilets, which saves potable water over time.
There are limitations, however, on where this water should be applied due to the risk of contaminants. The water should never be used to water edible plants, as the biological and chemical contaminants could be absorbed into the food source. Similarly, it must not be used in humidifiers or misters, as this would aerosolize the bacteria and mold spores, distributing them directly into the air for inhalation.