Where you really save: 6 habits after installing new windows
In short: New windows keep the heat in, but part of the saving depends on how you use them. Short, intense airing, lowered roller shutters at night and an uncovered radiator make a difference at no cost.
1. Air rooms briefly and fully
The biggest mistake is leaving a sash permanently tilted open. The wall around the window cools for hours while the air changes slowly. It is better to open the window fully 2–3 times a day for 5–10 minutes, and even shorter in winter. The air is replaced, while the walls and furniture stay warm.
If you can, open two windows on opposite sides of the flat – the air will change in a few minutes.
2. Turn the radiator down while airing
While the window is wide open, turn the radiator valve to the lowest setting. Otherwise you are heating air that goes straight outside.
3. Lower the roller shutters on winter nights
A lowered roller shutter creates a layer of air between the slats and the glass. That is extra protection from the cold at night, when it is coldest outside. In summer it works the other way round: a shutter lowered during the day on the sunny side keeps the room from overheating.
4. Do not cover the radiator
Long curtains and a wide window sill above the radiator can trap heat between the curtain and the glass. Let curtains end above the radiator, or hang them far enough away, so that warm air can flow freely into the room.
5. Watch the humidity
New windows seal well, so moisture from cooking, showering, drying laundry and breathing no longer escapes through gaps on its own. If you see droplets on the glass or damp corners, it is not a fault of the window but a sign that the air in the room is too humid.
Air the room right after cooking and showering.
Do not dry laundry in a closed room without airing.
Keep the room evenly warm; cold rooms get condensation on the glass sooner.
The recommended humidity at home is around 40–60%. An inexpensive hygrometer quickly shows whether there is a problem.
6. Seals and hardware once a year
Dry, cracked seals let air through. Once a year, clean and treat them, and lubricate the hardware. How to do it is explained in “PVC window maintenance”.
How much does this save?
The exact amount depends on the house, the heating and your habits, so we do not promise percentages. What is certain is that these habits cost nothing and help your new windows deliver what you paid for.