dead-air space

American  

[ded-air] / ˈdɛdˈɛər /

noun

1. an unventilated air space in which the air does not circulate.

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Etymology

Origin of dead-air space

First recorded in 1900–05

Example Sentences

This keeps it from being frozen in winter and from being overheated in summer, just as a dead-air space in the walls of a building protects from extremes of heat and cold.

From Project Gutenberg

The storm window reduces this to a minor percentage because the dead-air space between the two thicknesses of glass acts as an efficient means of insulation.

From Project Gutenberg

Or, better still, for the few earliest frames, have double-glass sash, the dead-air space making further protection unnecessary.

From Project Gutenberg