Brzix / Knowledge Center / PVC window draughts or condensation
🪟 PVC/Aluminium windows

PVC window draughts or condensation — adjustment or replacement?

Brzix · Updated 15 September 2026
Short answer: A draught usually points to a worn seal, hardware or a sash that does not close properly. Condensation on the room side is more often caused by humidity and cold glass, while moisture between panes usually means the sealed glazing unit has failed.

One window, several different problems

SymptomWhat should be checked
Draught around the sashSeal, hinges and hardware
Condensation on the room sideHumidity and ventilation
Moisture between panesSeal of the glazing unit
Rain enters around the frameJoints, drainage and installation

A quick check without dismantling

Look for a seal that is hard, cracked or out of its groove. Clean accessible drainage openings. If the sash rubs, do not force the handle.

When servicing makes sense

When the profile and glass are sound, adjusting the hardware or replacing the seal often stops a draught. Replace the whole window only when the profile, glazing unit or installation is seriously damaged.

What to tell the technician

Give the number and approximate size of the windows, explain where air or water appears, and send one close-up photo of the frame and one of the full sash.

Frequently asked questions

Is there a summer and winter adjustment?

Some hardware allows pressure adjustment, but maximum tightening can overload and damage the seal.

Why does the window mist up in the morning?

Warm, humid indoor air condenses on cold glass.

Can only the glass be replaced?

In many systems, the sealed glazing unit can be replaced without changing the frame.

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