The answer to whether you can safely drink water collected from a dehumidifier, even if boiled, is generally no. The water, known as condensate, is not designed for human consumption. Household boiling is not a sufficient purification method to remove all the harmful substances it may contain, so this water should never be used for drinking or cooking purposes.
The Origin and Impurities of Dehumidifier Condensate
A dehumidifier extracts moisture from the air by drawing humid air over cold coils. This process initially produces water that is pure, resembling distilled water because it is formed from water vapor leaving behind mineral deposits. However, this purity is only momentary, as the water immediately begins to collect contaminants once it leaves the air.
The collected moisture is quickly compromised by the internal components of the machine and the environment. The water passes over the cooling coils and drips into a plastic collection bucket, both of which can harbor contaminants. Metal coils, especially those containing copper or aluminum, can leach trace amounts of heavy metals into the water, a process that is not visible to the naked eye.
The stagnant water in the collection reservoir creates an ideal environment for biological growth. Mold spores, bacteria, and other microorganisms present in the air are condensed along with the moisture and then multiply within the collection tank. The water also picks up dust, lint, and airborne particles drawn through the unit, contributing to the overall impurity of the condensate.
Why Boiling Alone Is Insufficient for Safety
While boiling is a highly effective method for emergency water purification, its benefits are limited to biological hazards. Bringing water to a rolling boil for at least one minute will kill virtually all pathogens, including bacteria, viruses, and parasitic protozoa. This process effectively removes the risk of waterborne illness from microorganisms found in the stagnant collection tank.
However, boiling does not address the chemical and metallic contaminants present in dehumidifier water. Substances like heavy metals, such as lead or copper leached from internal parts, are heat-stable and remain in the water even after prolonged boiling. Volatile organic compounds (VOCs) that the dehumidifier may have pulled from the air will also not be completely removed; some may even become concentrated as the water evaporates.
Boiling can unintentionally increase the concentration of non-volatile impurities. As some of the water turns to steam, the remaining chemical and metallic contaminants are left behind in a smaller volume of liquid. To safely remove these compounds, the water requires advanced methods like distillation (boiling water and collecting only the purified steam) or treatment with a dedicated reverse osmosis filtration system.
Practical, Non-Potable Applications for the Water
Although the condensate is not safe for human consumption, its low-mineral content makes it suitable for several practical uses around the home. Since the water has been stripped of the calcium and magnesium found in tap water, it is excellent for use in appliances that can suffer from mineral buildup. Using dehumidifier water for these purposes is a sustainable practice that conserves potable water resources.
The water can be repurposed for various tasks due to its soft nature:
- Filling steam irons and humidifiers, which prevents limescale buildup in internal mechanisms.
- Cleaning non-porous surfaces like floors, windows, and cars, as it leaves fewer streaks and spots than hard tap water.
- Watering non-edible ornamental plants, as the low mineral content is beneficial to many houseplants.
- Pouring the collected water directly into the toilet bowl to aid in flushing, which helps reduce overall household water usage.
The water should never be used on plants intended for consumption, such as herbs or vegetables, due to the risk of trace metal or chemical absorption.