The key facts

  • Winter mode means maximum sash pressure, summer mode means reduced pressure; there is also a standard intermediate mode.
  • The pressure is checked with a sheet of paper: if it pulls out easily, adjustment is needed.
  • Trunnions are turned 180 degrees when switching from summer to winter mode and 90 degrees from standard mode; excessive force can damage the hardware.

What winter and summer modes are

As cold weather sets in, windows may need adjustment. As Nikolai Petin, an expert at the Lemana PRO hypermarket, told Gazeta.Ru, winter and summer modes are the adjustment of the pressure of the sash against the frame using the hardware. In the winter position, the pressure is maximum and the gaps between the seal and the frame are minimal, which reduces drafts and retains heat. In summer mode, the pressure is reduced to avoid overloading the seal and to provide natural ventilation. In addition to these two, plastic windows have a standard, or universal, mode — intermediate in pressure strength.

When adjustment is not needed and how to check the pressure

According to Petin, in the first few years, a quality new window usually only needs the standard mode in winter, so there is no need to change the adjustment without reason. The pressure can be checked with a sheet of paper: open the sash, place the sheet between the frame and the sash, and close the window. 'If the paper pulls out easily, the pressure is weak and adjustment may be needed. If the sheet is held tightly, the window is set correctly. The check should be repeated at several points around the perimeter,' the expert explains.

How to perform the adjustment

The adjustment is done using trunnions (eccentrics) — movable metal elements on the edge of the sash. In most systems, the trunnions have a mark in the form of a dot or a line. 'In the summer position, the mark faces the street; in the winter position, it faces the room. The rotation when switching from summer to winter mode is 180 degrees, and from standard mode it is 90 degrees,' says Petin. He warns that excessive force when turning the trunnion is unacceptable — it can damage the hardware.

Risks of constant maximum pressure

'Constant operation at maximum pressure accelerates seal wear and increases the load on the hardware. If after adjustment the handle closes with great effort, the pressure should be slightly reduced,' the expert advises. Additionally, heat loss can be reduced, according to him, with heat-saving film on the glass and windows with heating glass. 'Adjusting windows takes a few minutes and requires no special skills,' Petin concludes.