Is AC Water Distilled?
Yes, air conditioning water is distilled water, but it becomes re-contaminated almost immediately after it forms.
Air conditioners work by cooling warm air that passes over a cold coil (the evaporator coil). As the warm, humid air hits this cold surface, it cools rapidly, and the water vapor in the air condenses into liquid water, much like dew forms on grass.
This liquid water then drips down and is collected in a drain pan before being routed away, typically through a drain line.
Why AC Water is Initially Distilled
The process of evaporation and condensation is essentially a natural form of distillation. When water evaporates into the air as vapor, it leaves behind dissolved minerals, salts, and many impurities. When this pure water vapor then condenses back into liquid form, the resulting water is, in its original state, quite pure – similar to distilled water.
As stated in the provided reference: "It is distilled water". This highlights that the formation process yields water that fits the description of distilled water due to the removal of impurities during the phase change from gas to liquid.
The Reality: Immediate Re-contamination
However, the reference immediately adds a critical caveat: "but it gets re-contaminated immediately by the bacteria, mold spores, and whatever else is in the air rushing past it as it drips down into the drain pan."
This means that while the water initially forms as pure, distilled water, it doesn't remain that way for long. As it drips through the air within the AC unit and collects in the drain pan, it picks up various contaminants from the surrounding environment, such as:
- Bacteria
- Mold spores
- Dust particles
- Other airborne microbes
Is AC Condensate Usable as Distilled Water?
Because of this rapid re-contamination, the water collected from an air conditioner should not be considered equivalent to commercially produced distilled water for sensitive uses like irons, humidifiers, or medical purposes. It may contain biological contaminants and particulate matter that are not present in properly sealed, pure distilled water.
Think of it this way: the AC unit performs the 'distillation' step, but the collection method exposes the pure water to airborne impurities, undoing the purity achieved during condensation.
| Characteristic | Initially Formed AC Water | Bottled Distilled Water | Collected AC Condensate |
|---|---|---|---|
| Purity (Dissolved Solids) | High (Pure) | High (Pure) | High (Pure) |
| Biological Contaminants | Low (Pure) | Very Low (Sterile) | High (Contaminated) |
| Particulate Contaminants | Low (Pure) | Very Low | High |
| Usability (Sensitive) | Theoretically, but immediately contaminated | Yes | No |
Therefore, while the process creates distilled water, the final collected product is not suitable for applications requiring the purity of distilled water due to airborne contamination.
