File:BuildingPlenum-Unintended-BiggerYellow.png

Summary
Example of a typical commercial building with the space above the drop-ceiling acting as an air-return plenum.

If a fire were to start above the drop ceiling, toxic fumes would be drawn into the open-air system and potentially poison building occupants before they are aware of the fire.

Image created by Dale Mahalko using Microsoft Word 2007, screenshotted and saved as a PNG with Windows XP Paint.

If you want to make an SVG of this, knock yourself out. I don't have an SVG editor.

DMahalko 05:52, 23 October 2007 (UTC)