heat reservoir

American  

noun

Thermodynamics.

1. a hypothetical body of infinitely large mass capable of absorbing or rejecting unlimited quantities of heat without undergoing appreciable changes in temperature, pressure, or density.

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Example Sentences

At about 2,700 feet, it found a heat reservoir with temperatures of some 250 degrees Fahrenheit.

From The Wall Street Journal • Jan. 21, 2026

Because of this difference, water is a better heat reservoir than land – especially big bodies of water, like oceans.

From Salon • Jan. 4, 2023

Even an old air raid bunker in the Wilhelmsburg district has been transformed into a so-called “energy bunker”, with a large heat reservoir.

From The Guardian • Feb. 22, 2020

The oceans are a massive heat reservoir, absorbing some 90% of the warming from human-caused climate change.

From Science Magazine • Dec. 18, 2017

It'll have two bulky Hab batteries, the atmospheric regulator, the oxygenator, and my homemade heat reservoir.

From "The Martian" by Andy Weir