What is one of the basic methods of ventilation?

Natural draft is one of the basic methods of ventilation that relies on the natural movement of air due to differences in temperature and pressure. This method utilizes the properties of warm air, which is less dense than cool air, allowing it to rise and create a vacuum that draws cooler air in from the surrounding environment. This passive form of ventilation is commonly used in various settings, such as residential buildings and industrial spaces, where the design and layout can effectively harness natural airflow without the need for mechanical systems.

Natural draft is advantageous because it requires no energy input, making it cost-effective and environmentally friendly. It is also relatively low maintenance since there are no mechanical components that need regular servicing. This method is especially effective in climates where temperature variations are sufficient to promote adequate airflow.

In contrast, the other options refer to different methods of ventilation that either rely on mechanical systems or focus on specific aspects of air quality management. While they have their own benefits, they do not represent the fundamental principle of natural air movement as effectively as natural draft does.