Damper

damper
An adjustable metal plate controlling convection currents in a fireplace.
danchi ...

damper, muffler - a device that decreases the amplitude of electronic, mechanical, acoustical, or aerodynamic oscillations ...

A chimney damper is a metal spring door placed at the top of the chimney with a long metal chain that allows you to open and close the chimney from the fireplace.

Break Draught Damper - A flue damper
Break glass unit - A manual fire alarm call point with a breakable glass cover.
Break joints - Staggered joints ...

Smoke Chambers - The are immediately above the damper and smoke shelf of a fireplace in the chimney.
Smoke Shelf - A shelf at the base of the smoke chamber that provides proper smoke circulation within this chamber above the fireplace in the chimney.

See also: Floor, Door, System, House, Finish