Domakihub How to Prevent Condensation on Windows at Home
Stop dripping panes and mouldy frames with these proven ventilation and humidity fixes.
Reviewed by Domakihub home & decor pros Β· 2026-06-23 Β· 4 min read
Condensation on windows is one of the most common complaints in Greek homes, holiday rentals, and hotel rooms β especially during the cooler, damper months when the gap between indoor warmth and outdoor cold is at its widest. Left unchecked, those wet panes quickly lead to mould on frames, peeling paint, and musty air that guests notice immediately. The video above walks through ten practical tactics; the steps below give you a clear, ordered action plan you can work through this week.
Why Windows Collect Moisture
Condensation forms when warm, humid indoor air touches a cold surface β your window glass. The air can no longer hold its moisture and deposits it as water droplets. In Greece the problem peaks between November and March, when heating is on but ventilation is minimal and humidity from cooking, showers, and occupancy builds up inside tightly shut rooms.
Single-glazed aluminium frames found in older Greek apartments and many rental villas are especially prone because the glass and frame conduct cold directly from outside. Double-glazed units raise the inner pane temperature significantly, but even modern windows will sweat if the indoor humidity stays above roughly 55 % for extended periods.
When It Becomes a Real Problem
The occasional bead of water on a cold morning is not an emergency. Persistent condensation β water pooling on the sill, frost on the corners, or moisture visible between the panes of a double-glazed unit β signals something that needs fixing. For holiday-rental owners and hotel managers the stakes are higher: one negative review mentioning mould can cost you several bookings, and Greek property regulations increasingly expect landlords to maintain habitable indoor air quality.
5 Steps to Stop Window Condensation
- 1
Ventilate Every Room Daily
Open windows for 10β15 minutes each morning, even in winter. This flushes out the moisture-laden overnight air before it has a chance to settle on cold glass. In rental properties and hotels, build this into the housekeeping routine β a quick cross-draught between opposite windows is far more effective than cracking a single pane.
- 2
Run Extraction Fans in Wet Rooms
Kitchens and bathrooms generate the majority of household moisture. Make sure extraction fans are switched on while cooking or showering and kept running for at least 10 minutes afterwards. If your fan is weak or noisy, replacing it is one of the highest-return improvements you can make for condensation control β and for guest comfort.
- 3
Control Indoor Humidity with a Hygrometer
Buy a digital hygrometer (under β¬15 at most hardware stores in Greece) and aim to keep indoor relative humidity between 40 % and 55 %. If readings consistently exceed 60 %, run a dehumidifier in the worst-affected rooms. A single mid-sized dehumidifier can remove several litres of water from the air per day, which is often enough to eliminate window sweating entirely.
- 4
Raise the Window Surface Temperature
Cold glass is the trigger, so warming the pane helps. Keep curtains and blinds open during the day so radiator heat can reach the window. If you have heavy curtains that trap cold air against the glass overnight, consider switching to thermal-lined curtains that sit closer to the wall, or fit secondary glazing or window insulation film on problem panes. Upgrading to double or triple glazing is the long-term solution for older properties.
- 5
Seal Draughts and Insulate Frames
Counterintuitively, some draughty properties suffer less condensation because uncontrolled air movement dilutes indoor humidity. When you seal draughts β which you should, for energy efficiency β you must compensate with deliberate ventilation or a whole-house mechanical ventilation with heat recovery (MVHR) system. Check window seals and frames annually; cracked or perished rubber seals allow moisture to track into the frame cavity and appear as condensation between double-glazed panes, which means the sealed unit itself has failed and needs replacing.
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FAQ
- Is condensation on windows a sign of damp or a structural problem?
- Not necessarily. Surface condensation on the room-side of a pane is almost always caused by high indoor humidity and low glass temperature β a ventilation issue, not a structural one. However, if water appears between the two panes of a double-glazed unit, the sealed unit has failed and needs replacing, as no amount of ventilation will fix a broken seal.
- Can I use anti-condensation window products?
- Yes β temporary sprays and wipes that leave a hydrophilic coating can help reduce visible beading on glass during cold spells. They are useful for a holiday rental between seasons or while you address the root cause, but they do not solve underlying humidity problems and need reapplying regularly.
- How much does it cost to fix condensation in a Greek apartment or rental property?
- The cheapest fixes β improving ventilation habits, buying a hygrometer, and adding a dehumidifier β cost under β¬150 and often solve the problem entirely. Replacing failed double-glazed units runs β¬80ββ¬200 per pane depending on size and installer. Full window replacement (single to double glazing) is a larger investment of β¬300ββ¬700 per window but delivers energy savings, guest comfort, and long-term protection against mould damage.