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Why is the Sky Dark at Night?
A discussion of Olbers' Paradox, the Big Bang and related issues — 20th anniversary edition.

Copright © 1996 - 2016, P. Lutus

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The Heat Pump

As you read what follows, remember that heat energy naturally flows from a hot environment to a cold one until the temperatures are equal.

But we can use heat pumps to make heat go where we want — refrigerators and air conditioners are examples of heat pumps. There are now devices simply named "heat pumps," avoiding all pretense, whose task is to heat or cool a house or environment. All such devices take advantage of the relationship between pressure and temperature in a gas or liquid.

A typical heat pump uses electrical energy to drive a compressor. The compressor increases the pressure in one vessel and reduces it in another, in order to move (or "pump") heat from one place to another.

Here is a virtual heat pump. If you pass your pointing device across the elements in the image at the right, explanatory notes will appear below.

Heat pumps in the real world around us use special refrigerants that change from a gas to a liquid as they move through the system. This makes the heat pump more efficient, but the basic principles are the same as in this example.



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