---
url: https://www.eurocovers.eu/glossary/water-air-interface
term: Water-air interface
definition: The boundary between liquid water and atmospheric air, where evaporation, gas exchange, heat loss, and odor release occur. Floating covers remove this interface.
updated: 2026-05-25
---

# Water-air interface

The boundary between liquid water and atmospheric air, where evaporation, gas exchange, heat loss, and odor release occur. Floating covers remove this interface.

The **water-air interface** is the boundary between liquid water and atmospheric air at the
surface of a water body. Most of the operational pressures on industrial water — evaporation, gas
exchange (H₂S, VOC, methane), heat loss, and surface algae growth — occur at this interface.
Floating covers work by physically removing the water-air interface, eliminating the mass and heat
transfer that drives the operational pressures.

The AWTT-patented Hexprotect® AQUA hexagonal cover removes the water-air interface across 99%
effective surface coverage (per AWTT) without anchors — see [/heritage](/heritage) for the patent
and engineering history.