Window ventilation and insert arrangement

A window ventilation arrangement for ventilating a room, the window ventilation arrangement comprising:

• a slidable window assembly comprising a window frame, a first window and a slidable window, the window frame comprising an exterior window channel, an interior window channel, a peripherally extending channel-defining exterior portion, a peripherally extending channel-defining interior portion and a channel bottom;
• the exterior and interior window channels each comprising a window channel portion, the window channel portions each comprising an insert-receiving channel at the channel bottom and a raised channel portion extending upwardly from the channel bottom;
• a first window channel of the exterior and interior window channels being configured to provide an air-letting opening defined by the peripherally extending channel-defining exterior and interior portions, the first window received in the first window channel extending in a first dimension and a second dimension, the slidable window being slidably received a second window channel of the exterior and interior window channels and displaceable in a first direction and a second direction along at least one of the first and second dimensions within the second window channel for providing the air-letting opening or closing the air-letting opening, the insert-receiving channel of the first window channel having an insert channel width;
• and
• a removable window insert arrangement comprising a panel and a plurality of panel spacers, the panel comprising four corners, a first panel edge, a second panel edge opposite the first panel edge, and a panel thickness, the panel spacers each comprising a uniform spacer thickness and being attached to the panel at least at the four corners for providing an overall insert thickness at the first panel edge and the second panel edge, the overall insert thickness equaling the insert channel width, the window insert arrangement being removably insertable into the insert-receiving channel of the first window channel extending in parallel relation to the slidable window, the panel thereby providing a reduced air-letting opening for reductively ventilating the room.