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AC_Hacker · 09-17-13, 03:11 PM

To explain how heat pumps work, we need to understand a process that is basic in all of nature, but isn't fully understood by most people. That process is called "Change of State".

Change of state refers to the event of a substance changing from gas to liquid, or from liquid to solid. Water is an example that everyone is familiar with. Water can exist in different 'states' as a vapor, or as a liquid, or as a solid. When water is in each of these states, it is still water, it is still H2O.

When water is in the vapor state, it behaves in every way as a gas would behave. It is highly compressible, it can expand to fill the container it may find itself in. But it is still water, still H2O. "Steam" is another term for water vapor, but the word 'steam' also carries the connotation of heat... which gives us a clue as to what is going on here.

When water is in the liquid state, it behaves in every way as a liquid would behave. It is almost completely incompressible, but it can take the shape of the container it may find itself in. It is still water, still H2O. This is the most familiar form of water we know. When we hear the word "water", we think of liquid water. This is because in the temperature and pressure levels that humans are comfortable in, water is most frequently seen as a liquid.

When water is in the solid state, it behaves in every way as a solid would behave. It is almost completely incompressible, but it will not take the shape of the container it may find itself in. It is still water, still H2O.

What causes the differences between these different states of water? Why is water a vapor in some instances, and a liquid in other instances, and a solid in still other instances?

Our ordinary experience give us a clue that heat has something to do with it. So you could take a pan, put some ice in it, put the pan on a stove and turn on the heat.

After a while, you would see the ice start to melt, turn into liquid water, and then a while after that the heat from a stove would cause the water to boil and then turn to steam, or water vapor, until the pot was dry.

OK, great... Is it reversible?

(* To Be Continued... *)

-AC

09-17-13, 03:11 PM	#6
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	How Do Heat Pumps Work? To explain how heat pumps work, we need to understand a process that is basic in all of nature, but isn't fully understood by most people. That process is called "Change of State". Change of state refers to the event of a substance changing from gas to liquid, or from liquid to solid. Water is an example that everyone is familiar with. Water can exist in different 'states' as a vapor, or as a liquid, or as a solid. When water is in each of these states, it is still water, it is still H2O. When water is in the vapor state, it behaves in every way as a gas would behave. It is highly compressible, it can expand to fill the container it may find itself in. But it is still water, still H2O. "Steam" is another term for water vapor, but the word 'steam' also carries the connotation of heat... which gives us a clue as to what is going on here. When water is in the liquid state, it behaves in every way as a liquid would behave. It is almost completely incompressible, but it can take the shape of the container it may find itself in. It is still water, still H2O. This is the most familiar form of water we know. When we hear the word "water", we think of liquid water. This is because in the temperature and pressure levels that humans are comfortable in, water is most frequently seen as a liquid. When water is in the solid state, it behaves in every way as a solid would behave. It is almost completely incompressible, but it will not take the shape of the container it may find itself in. It is still water, still H2O. What causes the differences between these different states of water? Why is water a vapor in some instances, and a liquid in other instances, and a solid in still other instances? Our ordinary experience give us a clue that heat has something to do with it. So you could take a pan, put some ice in it, put the pan on a stove and turn on the heat. After a while, you would see the ice start to melt, turn into liquid water, and then a while after that the heat from a stove would cause the water to boil and then turn to steam, or water vapor, until the pot was dry. OK, great... Is it reversible? (* To Be Continued... *) -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...