Rene-NASA-Mooned-America

Explaining Heat & Cold / Chap. 10 p. 84
If you didn't realize that you were removing heat by extracting the vapor you might
conclude that a vacuum is inherently cold. Indeed, science fiction books, sci-fi movies, and
television space operas have led us to exactly that conclusion. But this is not true. If space
was as cold as we have been led to believe then any surface area of a space ship away from
the heated sections could become dangerously weak and susceptible to failure. Too much
cold, like too much heat, can seriously affect the structural integrity of most materials.
During both the Arctic and the Antarctic winter, temperatures can drop below minus 60° F.
Rubber loses much of its flexibility and metals become brittle. But this temperature, -51° C
or 222° K, is relatively hot compared to absolute zero at -273° C.
Refrigeration — A process which cools a substance by the physical removal of heat.
Mechanical refrigeration uses a lot of power, heavy motors, pumps and a refrigerant to
pump heat out of a well insulated container. The refrigerant must be able to store the heat it
absorbs from the container and must also be capable of releasing that heat in the heat
exchanger. Some type of pump is needed to move the hot refrigerant from the container to
the heat exchanger and then bring the cool refrigerant back again.
The heat exchanger is vital because it transfers the heat to a heat sink which on Earth is
either the air of our atmosphere or sometimes the water of a pond, river or ocean. Without a
place to dump the heat there would be no refrigeration or air conditioning as we know them.
If you ran an air conditioner in a sealed room the temperature in the room would climb even
though directly in front of the machine there would be a flow of colder air.
Explosive Freezing — The rapid decompression of a liquid or a gas.
In a CO 2 extinguisher, carbon dioxide, a colorless gas is stored under high pressure in a
liquid state. When we pull the trigger the liquid, released from the pressure, rushes out into
the air instantly exploding into a fine spray of extremely cold and frozen particles called dry
ice. The latent heat is lost because of the tremendous change (drop) in pressure.
Fuel Cells — A generator that combines a fuel and oxygen, and primarily produces DC
electricity and water instead of heat.
These units are similar to batteries. However, unlike a battery — which uses a chemical
change to store electrical energy — a fuel cell uses a chemical process to generate relatively
small amounts of electricity. Also, unlike batteries the fuel (chemicals) are not stored internally,
but are fed in as the electricity is needed.
Spontaneous Combustion —A process where oxidation creates more heat than is being
emitted.
The temperature will rise in a closed system (house, car, or LEM) when more heat is
absorbed than given off. As you will see, a space ship or space suit is no different. In
summation, if a vacuum was inherently cold we could air-condition and refrigerate simply
by putting a vacuum chamber around the unit's radiator and then pulling a vacuum on it.
NASA MOONED AMERICA! / Rene