What type of window only allows a limited percentage for ventilation?

The type of window that allows a limited percentage for ventilation is best described by the characteristics of horizontal sliding and single/double hung windows. These kinds of windows typically have a design that restricts how much of the window can open, resulting in less effective ventilation compared to other window types.

Horizontal sliding windows slide open horizontally, which means only part of the window can be opened at once, limiting airflow. Similarly, single and double hung windows have a vertical opening mechanism, where only the top or bottom sash can be opened, again restricting the total ventilation area.

In contrast, casement windows and awning windows can open fully and allow for more considerable airflow and ventilation. Bay windows, while they may allow some ventilation when opened, are primarily designed for aesthetics and may not provide significant airflow compared to the other types. Understanding these functional aspects of different window types helps in assessing their suitability for ventilation needs in various contexts.