How To Get Rid Of Condensate On Plastic Windows: Expert Recommendations

How To Get Rid Of Condensate On Plastic Windows

“After the installation of the plastic windows, they started to sweat every morning.” It is a very common scenario. Why is this happening? Old wooden windows sweat less often than plastic ones, but the reason is their poor tightness. If earlier moisture freely escaped outside through the pores in the wood and the cracks in the window, then after installing the plastic ones, all moisture remains “locked” inside the room. So, the high tightness and energy efficiency of PVC structures causes condensation on the glass. In order for moisture from the air to begin to settle on surfaces in the form of droplets, two conditions must be met:

  • High humidity inside;
  • Low surface temperature (the dew point).

Plastic windows are usually the coldest surface in the room. Therefore, moisture from the air will condense on them. The higher the humidity in the room and the lower the temperature on the glass, the more condensation will occur. Does it mean that you should replace your plastic windows? Let’s consider the solutions, from the easiest one to the new window installation from the best supplier. 

How To Deal With Condensation?

So, condensation has two reasons — high humidity and low temperature on the surface of the window. If you eliminate them, the problem will be solved by itself. What can be done?

1. Better room ventilation 

If there is poor ventilation in the room, problems with fogging of windows cannot be avoided. The issue is solved by installing micro-ventilation or another device on the window. 

2. Glass unit replacement 

The inner glass of a single-chamber window will be cold in winter — therefore, condensation will actively form on it. Replacing a single-chamber window with a double-chamber one can solve the problem, or significantly reduce the level of fogging.

3. Window adjustment or a seal replacement 

Sometimes the reason for hypothermia of the window is blowing around the perimeter of the sash due to insufficient tightness, distortion, or loss of elasticity by the sealant. Solving these problems can eliminate fogging.

​​4. Jambs insulation 

If the temperature of the jambs is low, condensate will also fall on them. Therefore, the jambs are either initially made of materials with low thermal conductivity (sandwich panel), or subsequently insulated.

5. Installation of new window

A radical solution is the modification of the mounting seam or the complete reinstallation of the window. At the same time, the window itself should be correctly located in the opening, and the seam should be formed using a three-layer technology. In this case, special tapes are used, they will serve as a vapour barrier from the inside and vapour-permeable from the outside. Due to this, the humidity in the room is normalized and the prerequisites for the appearance of condensate are eliminated.

In addition, replacing the window sill with a narrower one or installing a special ventilation grate in it can help. This will increase the temperature of the window due to more efficient heating from the radiator.