Dew point temperature: definition and challenges

What is dew point temperature?

La Dew point temperature corresponds to the temperature at which the air becomes saturated with water vapor and begins to produce condensation.
At this very moment, the relative humidity reaches 100%, and the water vapor in the air is transformed into droplets. It is this phenomenon that causes dew at sunrise or the appearance of humidity on a cold surface.

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How does dew form?

Dew usually occurs when the air cools during the night.
At sunrise, surfaces (plants, roofs, outdoor objects) are often colder than the ambient air.
When the air temperature drops to dew point, the water in it condenses — this is the appearance of dew.

The same principle explains condensation inside homes: if a wall (wall, window, tile) is colder than the dew point temperature, water settles on it.

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How do you calculate dew point temperature? (Simplified version)

In reality, the calculation is based on scientific equations that link:

• the quantity of water vapor present in the air,
  
  
• the ambient temperature,
  
  
• the saturated vapour pressure of water.
  
  

Instead of detailing the formulas, let's remember this:

👉 If the air contains a certain amount of water vapor, we can determine at what temperature this water will condense by comparing this value to water saturation data.

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Simple example

In a room at 20°C and 50% relative humidity :

• the air contains a moderate amount of water vapor,
  
  
• by comparing this quantity to the saturation values of the water, we get that
  the dew point temperature is around 9.3°C.
  
  

This means that:

➡️ If a surface of the room falls to 9.3°C, there will be condensation on it.

This is exactly what happens on cold walls, windows in winter or thermal bridges.

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Why is the dew point important?

Understanding this temperature allows you to:

• anticipate the risks of condensation in a room,
  
  
• prevent the appearance of mold,
  
  
• avoid wall damage,
  
  
• better manage heating,
  
  
• optimize ventilation.
  
  

As soon as a surface is colder than the dew point → condensation occurs.

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Stabilize humidity to limit condensation

La condensing interior depends on two factors:

• the temperature of the surfaces,
  
  
• the amount of water vapor in the air.
  
  

By reducing this ambient humidity, we decrease the probability that the air will reach its dew point.

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Air Sponge: a passive solution to limit excess humidity

Air Sponge is based on a patented mesoporous material capable of adsorbing moisture when the level exceeds approximately 60%, then Release it naturally when the air dries up.

Its advantages in a context related to the dew point:

• It stabilizes the ambient humidity, reducing the risks of reaching 100% Relative Humidity (RH),
  
  
• It works without electricity,
  
  
• It does not saturate permanently,
  
  
• no waste unlike silica gel bags or salt tablets,
  
  

flexible installation (adhesive, magnetic, tape), ideal for areas sensitive to condensation.