A little condensation during a cold snap can have a different cause from water running down the frame every morning. The useful question is not simply whether a window is old: it is where moisture appears, when it appears, and whether ventilation and indoor humidity are being managed.
Condensation forms when moist indoor air touches a surface cold enough for water vapour to condense. A thin film on the room-side glass during a sharp temperature drop may be temporary. Repeated droplets, wet sills, frost between panes, peeling paint or mould around the frame deserve closer attention. Record which rooms and windows are affected, the outdoor conditions, when cooking or showering occurred, and whether the issue changes when exhaust fans run. Moisture between sealed panes can indi...
Use bathroom and kitchen exhaust fans when generating moisture, and confirm that they exhaust outdoors rather than into an attic or wall cavity. Run them for the period recommended by the fan or building guidance after bathing or cooking. Use lids when boiling water and avoid drying large amounts of laundry indoors without adequate ventilation. If your furnace has a humidifier, check its control and lower it when window condensation appears, following the equipment instructions. If the home has...
There is no single relative-humidity setting that fits every Ottawa home and every outdoor temperature. Cold exterior surfaces can collect moisture even when the indoor humidity reading seems comfortable. Use a hygrometer as a trend indicator, not a diagnosis. If condensation grows during colder weather, lower humidification gradually and observe whether the glass dries while occupants remain comfortable. Do not respond by sealing or covering a window in a way that traps moisture against the fr...
Arrange an inspection if water repeatedly pools, mould returns after cleaning, finishes soften, drafts are strong, the window is difficult to operate, or condensation appears between panes. A contractor should explain whether the likely issue is a window seal, air leakage, thermal bridging, drainage, or indoor moisture—not jump straight to replacing every window. If the problem began after new windows, insulation or air-sealing work, contact the installer and review the project scope. A more ai...
Not necessarily. Room-side condensation can relate to indoor moisture, ventilation, air circulation or cold surfaces. Moisture between sealed panes can point to a failed glass unit. Diagnose the pattern before choosing a repair.
The suitable level varies with outdoor temperature, window performance and the home’s ventilation. If condensation appears, reduce humidification gradually and monitor the result; ask an HVAC or building-envelope professional if moisture persists.
Follow the HRV manufacturer’s operating instructions rather than disabling ventilation without a plan. Keep its filters and exterior openings clear, and ask a qualified technician to assess persistent humidity or comfort issues.