What type of ventilation uses a smoke ejector to remove products of combustion?

Negative-pressure ventilation is defined by its method of creating a lower pressure area inside a structure, which facilitates the removal of smoke and gases. In this type of ventilation, smoke ejectors or fans are utilized to forcibly expel the hazardous products of combustion from the building. This process involves placing the smoke ejector at an exit point, such as a window or door, and operating it to draw the smoke out, while simultaneously allowing fresh air to enter the structure through other openings.

This approach is particularly effective in enhancing visibility and improving conditions inside a smoke-filled environment, aiding in the safe and efficient performance of firefighting operations. The other types of ventilation have distinct characteristics that make them unsuitable for this specific function. For instance, natural ventilation relies on the natural buoyancy of smoke and the effects of wind to facilitate airflow without mechanical assistance, while positive-pressure ventilation uses fans to blow fresh air into the structure, which may not effectively remove smoke in the same way as negative-pressure ventilation. Hydraulic ventilation involves using a water stream to create a mist or fog that helps cool and disperse smoke but does not utilize a smoke ejector for removal.