I might have the name of the component wrong, but they were designed to self-destruct after so many hours of the TV being on. I thought they were called Thermistors, but as usual, I could be wrong.
Although they no longer make this type of AC unit. At my Holmes Avenue apartments, all the AC units were shaped like an upside down L. The components were all in the same metal box, but where the compressor and fan were located was below the window, and only the vents were up where a normal window AC would go. This was eons ago and they were super quiet. Rather than cut out the wall to fit a window type AC unit in their place, I bought a Split System AC unit for each as they went kaput, and the model I bought, the blower head fit the hole already in the concrete block wall. I could mount the Compressor/Evaporator unit on the wall just below it outside. You could not hear these things running inside the apartment, and could only hear the fan if you turned it on high.
Now outside was a different story. You could hear all of them running and they echoed between the two buildings, hi hi.
When we had the computer room at the florist, the AC there too was a split-system, with the fan unit mounted up by the ceiling blowing toward the computer. Don't know how noisy it was, but it wasn't as noisy as the computer system itself. That 3'x3'x30" tall hard drive made quite a lot of noise. It was a Wang VS system.
Another Win For Linux
Re: Another Win For Linux
I recall walking the campus of Washington University way back when my daughter was attending school there. One of the things that impressed me was a smallish building across the road from an auditorium. That building had all the a/c motors and evaporators in it. There were ducts underground to pipe the cold air into the auditorium. I have no idea how they did that, but we were perfectly comfortable during the entire performance. A lot of commercial buildings have the compressor units up on the roof, which makes a lot of sense given that cold air is more dense than warm air and will fall to the ground. But piping it across a roadway does not make sense to me. LOL
I recall seeing those inverted "L" air conditioners when I was young. I don't think we ever owned one.
I recall seeing those inverted "L" air conditioners when I was young. I don't think we ever owned one.
Re: Another Win For Linux
Not to be funny here, but the further away from the evaporator, the condenser and compressor are placed, the more efficient the operation of the AC unit is.
Back when we had a pond at our florist, we had three flower coolers, and the lines from the compressors to the evaporators ran through coils in the pond. The lines from the evaporators to the condensers were direct lines.
The high pressure line from the compressor to the evaporator is very hot, so the cooler you can make it, the more efficient the evaporator functions. The cool line running back to the condenser doesn't matter too much, the idea of the condenser is to remove what heat is brought back via the evaporator line.
In a window AC unit or an outdoor whole house AC unit, a fan blows air through the condenser to help cool it down, the cooler they can make it, the more efficient the whole system becomes.
But you also have to weigh in the fact of how much it costs to run the fan motor that cools the condenser. So going to a bigger or faster fan motor could be self-defeating. But running the line leading to the evaporator in ways it can get cooled down with no cost, such as passing through a coil in the pond, or buried in earth is beneficial. Except in earth, eventually the earth itself warms up and is not as efficient as in water.
When you see huge building with water fountains, besides being there for decoration, they are often part of the AC system, and to keep the water from getting to hot, they may be spraying fountain heads into the air to cool the water.
The biggest problem with the inverted L AC units is, they normally had to be installed from outside.
Way too many people dropped them trying to install them from inside the house, hi hi.
Back when we had a pond at our florist, we had three flower coolers, and the lines from the compressors to the evaporators ran through coils in the pond. The lines from the evaporators to the condensers were direct lines.
The high pressure line from the compressor to the evaporator is very hot, so the cooler you can make it, the more efficient the evaporator functions. The cool line running back to the condenser doesn't matter too much, the idea of the condenser is to remove what heat is brought back via the evaporator line.
In a window AC unit or an outdoor whole house AC unit, a fan blows air through the condenser to help cool it down, the cooler they can make it, the more efficient the whole system becomes.
But you also have to weigh in the fact of how much it costs to run the fan motor that cools the condenser. So going to a bigger or faster fan motor could be self-defeating. But running the line leading to the evaporator in ways it can get cooled down with no cost, such as passing through a coil in the pond, or buried in earth is beneficial. Except in earth, eventually the earth itself warms up and is not as efficient as in water.
When you see huge building with water fountains, besides being there for decoration, they are often part of the AC system, and to keep the water from getting to hot, they may be spraying fountain heads into the air to cool the water.
The biggest problem with the inverted L AC units is, they normally had to be installed from outside.
Way too many people dropped them trying to install them from inside the house, hi hi.
Re: Another Win For Linux
I have to give the engineers at the University the benefit of a doubt because I know very little about how a/c works. You pump a liquid into an evaporator where the liquid turns into a gas. The surrounding air cools due to the evaporation process. That cool air is blown by a fan into the area that needs it. The gas created by the evaporating liquid is sent to a compressor that turns it back into a liquid, thus generating heat. At least that's how I think it works. Keeping the heat at a reasonable temperature can be facilitated by liquid cooling much like certain computer processors we know about. Thus the compressor probably has to work less if the gas temperatures are low. I'm pretty sure the differential between the hot side and the cold side is in the area of 22 degrees. At least that's what the service guy told me last time he was out. So, if' it's 95 degrees outside, the best you can expect form the cold air inside is 73 degrees. Sounds about right and explains why augmenting the compressor cooling is beneficial.
Re: Another Win For Linux
Well sorta Yogi. I'm going to confuse the issue by saying, an AC unit does not technically supply cold air to a room. What it actually does is Remove Heat from the air that passes through the evaporator. I know, not logical, but that is what the unit actually does. However, in the process of removing the heat from the air, the air returned to the room is cooler, hi hi.
Although I took AC repair at a trade skewl, I disagreed about the removal of heat and gave an example.
Back then we had air guns and air brushes that used cans of freon to power them. As you used the can of freon, the can would get very cold and the output would decrease until you let the can warm up again. So in my minds eye the evaporation of freon creates cold, and with a fan behind it blows the cold air into the room.
Unfortunately, that got me a lot of extra homework to do, so they could prove my analogy was wrong.
Turns out, I was wrong, and for a very simple reason. Spraying freon into the air does not cool the air, but exhausts the freon in the can, evaporation in the can causes it to get cold.
However, that is not a Closed Recirculatory System, as an AC unit is.
What the fan behind the evaporator is actually doing is blasting warm air through the evaporator so it will heat up, then the heat is transferred outside to the condenser where it is cooled back down again, thus removing the heat sent to it from the evaporator. The condenser is also removing the excess heat created by the compressor turning the gas back into a liquid.
Regardless of the technicalities, an AC unit still blows cooled air into the room, hi hi.
As an aside: The differential from hot side to cold side is not a fixed amount of degrees as your AC guy said.
It depends on several factors, the first of which is the coolant used.
Think about your car AC for a minute, and how cold the air is that comes out of those vents, compared to the cold air that comes out of a window AC unit.
There are walk-in refrigerators, and walk-in freezers. Most walk-in freezers have condensers outside that are more than twice the size of a walk-in refrigerator.
An ammonia system produces a differential more than twice that of the various freon blends. But as you know, an ammonia system is highly dangerous, so you don't see to many of them around anymore, except in huge buildings.
I used to have a Black Trans-Am, the 50th Anniversary Special Edition in fact. The condenser in that car was at least double the size of one you would find in a White Trans-Am for the same year. The car being Black needed it.
One of my frau's cousins bought two Red Mustangs, one a hard top, the other a convertible, both same year, with the same size motor. The condenser in the convertible is also twice the size of the one in the hard top.
The only thing I can surmise from this is, the condenser plays a bigger role in how much heat the evaporator removes from the car or a freezer. Which honestly seems bass ackwards to me, hi hi.
Although I took AC repair at a trade skewl, I disagreed about the removal of heat and gave an example.
Back then we had air guns and air brushes that used cans of freon to power them. As you used the can of freon, the can would get very cold and the output would decrease until you let the can warm up again. So in my minds eye the evaporation of freon creates cold, and with a fan behind it blows the cold air into the room.
Unfortunately, that got me a lot of extra homework to do, so they could prove my analogy was wrong.
Turns out, I was wrong, and for a very simple reason. Spraying freon into the air does not cool the air, but exhausts the freon in the can, evaporation in the can causes it to get cold.
However, that is not a Closed Recirculatory System, as an AC unit is.
What the fan behind the evaporator is actually doing is blasting warm air through the evaporator so it will heat up, then the heat is transferred outside to the condenser where it is cooled back down again, thus removing the heat sent to it from the evaporator. The condenser is also removing the excess heat created by the compressor turning the gas back into a liquid.
Regardless of the technicalities, an AC unit still blows cooled air into the room, hi hi.
As an aside: The differential from hot side to cold side is not a fixed amount of degrees as your AC guy said.
It depends on several factors, the first of which is the coolant used.
Think about your car AC for a minute, and how cold the air is that comes out of those vents, compared to the cold air that comes out of a window AC unit.
There are walk-in refrigerators, and walk-in freezers. Most walk-in freezers have condensers outside that are more than twice the size of a walk-in refrigerator.
An ammonia system produces a differential more than twice that of the various freon blends. But as you know, an ammonia system is highly dangerous, so you don't see to many of them around anymore, except in huge buildings.
I used to have a Black Trans-Am, the 50th Anniversary Special Edition in fact. The condenser in that car was at least double the size of one you would find in a White Trans-Am for the same year. The car being Black needed it.
One of my frau's cousins bought two Red Mustangs, one a hard top, the other a convertible, both same year, with the same size motor. The condenser in the convertible is also twice the size of the one in the hard top.
The only thing I can surmise from this is, the condenser plays a bigger role in how much heat the evaporator removes from the car or a freezer. Which honestly seems bass ackwards to me, hi hi.
Re: Another Win For Linux
The most common analogy used for a/c output is melting ice. The cold coming from the a/c unit used to be stated in how many tons of ice melting (or fractions thereof) to do the same job. That analogy depicts hot air being blown across a mass of ice, which is surrounded by cold air. The hot air is cooled down and there is a net loss of heat as a result. So, what is really happening there? Is the hot air cooling or is the cool air heating? 
The differential I cited earlier relating to the cold vs hot side of an a/c unit applies to the system in my house and others like it throughout the state of Missouri. The cooling fluid isn't freon nor amonia. It most likely is "... R-410A by a brand name rather than its generic description. It may be called Suva® 9100, Genetron® AZ-20®, Puron®, or another brand name. Since it is a hydro-fluorocarbon (HFC), it does not cause ozone depletion." So says Google anyway. I trust the service guy knew what he was talking about, but who knows? It seemed reasonable when he told me.
We had what I call a drive-by member of this forum many years ago. He signed up and posted one question, then was never heard from again. I recall the question and figured he came back once in a while to laugh at the responses, but nobody posted an reply. The question was something like this, "Two rooms are next to each other. One has hot air and the other has cold air. When the door between them is opened, does the hot air flow into the cold room, or does the cold air flow into the hot room?" I did a lot of searching for answers among the physics crowd, particularly those interested in thermo-dynamics, but I could not find a direct answer to the question. It's probably a chicken and egg type thing but I don;t know enough about entropy to recognize it as such. I'm happy to think both things happen simultaneously.
The differential I cited earlier relating to the cold vs hot side of an a/c unit applies to the system in my house and others like it throughout the state of Missouri. The cooling fluid isn't freon nor amonia. It most likely is "... R-410A by a brand name rather than its generic description. It may be called Suva® 9100, Genetron® AZ-20®, Puron®, or another brand name. Since it is a hydro-fluorocarbon (HFC), it does not cause ozone depletion." So says Google anyway. I trust the service guy knew what he was talking about, but who knows? It seemed reasonable when he told me.
We had what I call a drive-by member of this forum many years ago. He signed up and posted one question, then was never heard from again. I recall the question and figured he came back once in a while to laugh at the responses, but nobody posted an reply. The question was something like this, "Two rooms are next to each other. One has hot air and the other has cold air. When the door between them is opened, does the hot air flow into the cold room, or does the cold air flow into the hot room?" I did a lot of searching for answers among the physics crowd, particularly those interested in thermo-dynamics, but I could not find a direct answer to the question. It's probably a chicken and egg type thing but I don;t know enough about entropy to recognize it as such. I'm happy to think both things happen simultaneously.
Re: Another Win For Linux
I'll have to remember to get back to this. Gotta Run!
Re: Another Win For Linux
I may be wrong, but I can answer that question.
First, let's assume it is a Sliding Door, because a normal door would cause Eddy Currents which would sway the answer.
First, I'm sure we will agree that cold air falls, and hot air rises!
So, when the sliding door is opened, the heavy cold air would push itself into the hot room at floor level, and the hot air would push itself into the cold room at the top of the door level. An equal amount of air would transfer between the two rooms. If the door is left open long enough, the cool room will warm up, and the warm room will cool down, however, the temperature of the two rooms when they do equalize will be warmer than the difference between them, unless the two rooms are totally air tight and 100% insulated. Why because of the distance between the molecules. Cold air is dense, compared to hot air, but the compression factor of the cold air is lost, possibly due to friction between the molecules.
First, let's assume it is a Sliding Door, because a normal door would cause Eddy Currents which would sway the answer.
First, I'm sure we will agree that cold air falls, and hot air rises!
So, when the sliding door is opened, the heavy cold air would push itself into the hot room at floor level, and the hot air would push itself into the cold room at the top of the door level. An equal amount of air would transfer between the two rooms. If the door is left open long enough, the cool room will warm up, and the warm room will cool down, however, the temperature of the two rooms when they do equalize will be warmer than the difference between them, unless the two rooms are totally air tight and 100% insulated. Why because of the distance between the molecules. Cold air is dense, compared to hot air, but the compression factor of the cold air is lost, possibly due to friction between the molecules.
Re: Another Win For Linux
The law of entropy says, among other things, that the universe is in a constant struggle to seek equilibrium. The two room problem makes it easier to visualize in that eventually the temperature in the two rooms would equalize, assuming no further stimulus to create or lose heat. I don't know where it would settle. If the hot room was 100 and the cold room was 50 degrees, my instincts tell me that the equilibrium point would be 75 degrees. Why it would be more or less than that escapes me. But as I said earlier, I don't know enough about entropy to ask intelligent questions. 
Re: Another Win For Linux
I don't know the real reason why either, except in atmosphere heat always wins out over cold.
In no atmosphere, cold will always win out over heat.
Logically, as you pointed out, the end temperature should be 75 degrees, but in reality it will end up closer to 80 degrees.
If it were not for the fact I used to fly hot air balloons, I wouldn't understand it at all.
The reason a hot air balloon can fly is because of the distance between the warm molecules inside the balloon is greater than the distance between the molecules of the cooler air outside.
That being said, just heating up a hot air balloon will not give it lift, because even though the air inside the balloon is now hot, there is no distance increase between the molecules.
Say that again!
Inside the closed balloon, simply heating the air does not cause the warm molecules to be able to move apart from each other. Hot or Cold, the balloon will technically weigh the same.
The rising HOT air, COMPRESSES the air in the top of the balloon.
So although it keeps getting hotter, the molecules are under compression, so they do not expand the distance between them.
OK, so then how do you make the balloon fly?
You open a small vent at the top of the balloon to let the compressed air out, allowing the molecules to spread out, thus the molecules inside the balloon are now farther apart than the molecules outside the balloon and it is now lighter than air.
In real life, there are permanent vents in the top of a balloon to prevent compression, but it was not always so in the early days of ballooning. They used the compression to an advantage. Let out just enough air to give the balloon lift, and in an emergency situation, you could pull open a top vent causing the balloon to jump higher faster.
Some acrobatic balloons still have closed vents on the top so they can do some of the tricks they like to do.
But in this day and age, with the fancy burners used to produce the heat, a set of permanently open vents prevents accidents. A new balloonist could pull the cord to produce more heat, but still go crashing to the ground if those vents were closed. So, there are now permanently open vents on all balloons unless they are designed for acrobatic use.
Now back to our two rooms. Cold air absorbs heat, but hot air does not absorb cold. Which might be a reason why the two rooms final balanced temperature would be warmer than the logical assumption.
In no atmosphere, cold will always win out over heat.
Logically, as you pointed out, the end temperature should be 75 degrees, but in reality it will end up closer to 80 degrees.
If it were not for the fact I used to fly hot air balloons, I wouldn't understand it at all.
The reason a hot air balloon can fly is because of the distance between the warm molecules inside the balloon is greater than the distance between the molecules of the cooler air outside.
That being said, just heating up a hot air balloon will not give it lift, because even though the air inside the balloon is now hot, there is no distance increase between the molecules.
Say that again!
Inside the closed balloon, simply heating the air does not cause the warm molecules to be able to move apart from each other. Hot or Cold, the balloon will technically weigh the same.
The rising HOT air, COMPRESSES the air in the top of the balloon.
So although it keeps getting hotter, the molecules are under compression, so they do not expand the distance between them.
OK, so then how do you make the balloon fly?
You open a small vent at the top of the balloon to let the compressed air out, allowing the molecules to spread out, thus the molecules inside the balloon are now farther apart than the molecules outside the balloon and it is now lighter than air.
In real life, there are permanent vents in the top of a balloon to prevent compression, but it was not always so in the early days of ballooning. They used the compression to an advantage. Let out just enough air to give the balloon lift, and in an emergency situation, you could pull open a top vent causing the balloon to jump higher faster.
Some acrobatic balloons still have closed vents on the top so they can do some of the tricks they like to do.
But in this day and age, with the fancy burners used to produce the heat, a set of permanently open vents prevents accidents. A new balloonist could pull the cord to produce more heat, but still go crashing to the ground if those vents were closed. So, there are now permanently open vents on all balloons unless they are designed for acrobatic use.
Now back to our two rooms. Cold air absorbs heat, but hot air does not absorb cold. Which might be a reason why the two rooms final balanced temperature would be warmer than the logical assumption.
Re: Another Win For Linux
Why did I think of apples and oranges when I read your last comments?
The first thing to make clear is that the laws of physics will not be violated by us mere mortals. I may not fully understand those laws, but they are in place nonetheless. The spacing between atoms in any matter is due to the thermal energy contained within the atom. The temperature increases the spacing because heat energy is added and thus causes the atomic particles to vibrate faster. So, it's the addition of heat energy that increases the spacing. Loss of said energy will conversely decrease the spacing. No issues there, right?
When you heat the gas inside a closed container, thermal expansion takes place more intensely at the source of the heat than it does at some distance. Thus the phenomena of compression you cited takes place inside a hot air balloon. But the strong force of atoms will not be denied. That space must increase one way or another. In most cases the balloon material is stretched and forms, well, a balloon. If you keep heating the closed balloon, it will explode. But that never happens in reality. The balloon is porous and air escapes via the cracks in the seams and all that.
The second concept at work is that of buoyancy. If the air inside the balloon is less dense than the air outside, i.e. weighs less per given unit, the balloon will rise upward. A more vivid analogy would be one of those rubber balloons kids play with. Inflate it at the bottom of a lake and what happens? It rises because the air inside is less dense than the water outside. Same logic applies to hot air balloons.
If you do not vent the hot air balloon, it won't rise because the air inside (volume) weighs the same as the air outside regardless of the temperature. The space between the molecules is greater and causes the balloon to expand, but the heat alone does not make the balloon lighter than the outside air. Thus, venting the balloon to allow the colder air to escape causes the constant volume hot air to weigh less than it's cooler counterpart. This differential of weight per given volume is what makes the balloon rise and is known as buoyancy.
Cold air is compressed in comparison to the hot air, true. The compression increases as the air becomes hotter if there is no vent to let the colder air escape. Also true. The compression may change the shape of the balloon, but it's the buoyancy that makes the event uplifting. The pilots of said hot air balloons all have advanced degrees in wizardry. It takes a lot of skill and instinct to control air flow in one of those balloons, but it's all done within the confines of physical laws of nature.
So, back to the two room proposition. When the cold air meets the hot air an exchange of thermal energy takes place. The high energy of the heated room gets distributed evenly, eventually, throughout the cold room. Assuming everything is equal and there are no losses, equilibrium will be established via the law of entropy. The temperature must settle at 75 degrees. Since energy is neither created nor destroyed it can't be anything else at the equilibrium point. Even if all that reasoning is flawless, I can't say if the transfer of heat energy is due to radiation of the hot or absorption by the cold. LOL
The first thing to make clear is that the laws of physics will not be violated by us mere mortals. I may not fully understand those laws, but they are in place nonetheless. The spacing between atoms in any matter is due to the thermal energy contained within the atom. The temperature increases the spacing because heat energy is added and thus causes the atomic particles to vibrate faster. So, it's the addition of heat energy that increases the spacing. Loss of said energy will conversely decrease the spacing. No issues there, right?
When you heat the gas inside a closed container, thermal expansion takes place more intensely at the source of the heat than it does at some distance. Thus the phenomena of compression you cited takes place inside a hot air balloon. But the strong force of atoms will not be denied. That space must increase one way or another. In most cases the balloon material is stretched and forms, well, a balloon. If you keep heating the closed balloon, it will explode. But that never happens in reality. The balloon is porous and air escapes via the cracks in the seams and all that.
The second concept at work is that of buoyancy. If the air inside the balloon is less dense than the air outside, i.e. weighs less per given unit, the balloon will rise upward. A more vivid analogy would be one of those rubber balloons kids play with. Inflate it at the bottom of a lake and what happens? It rises because the air inside is less dense than the water outside. Same logic applies to hot air balloons.
If you do not vent the hot air balloon, it won't rise because the air inside (volume) weighs the same as the air outside regardless of the temperature. The space between the molecules is greater and causes the balloon to expand, but the heat alone does not make the balloon lighter than the outside air. Thus, venting the balloon to allow the colder air to escape causes the constant volume hot air to weigh less than it's cooler counterpart. This differential of weight per given volume is what makes the balloon rise and is known as buoyancy.
Cold air is compressed in comparison to the hot air, true. The compression increases as the air becomes hotter if there is no vent to let the colder air escape. Also true. The compression may change the shape of the balloon, but it's the buoyancy that makes the event uplifting. The pilots of said hot air balloons all have advanced degrees in wizardry. It takes a lot of skill and instinct to control air flow in one of those balloons, but it's all done within the confines of physical laws of nature.
So, back to the two room proposition. When the cold air meets the hot air an exchange of thermal energy takes place. The high energy of the heated room gets distributed evenly, eventually, throughout the cold room. Assuming everything is equal and there are no losses, equilibrium will be established via the law of entropy. The temperature must settle at 75 degrees. Since energy is neither created nor destroyed it can't be anything else at the equilibrium point. Even if all that reasoning is flawless, I can't say if the transfer of heat energy is due to radiation of the hot or absorption by the cold. LOL
Re: Another Win For Linux
ON the two room deal, you would be correct if both rooms were at 100% efficient insulation, which is something I don't think exists. Assuming the cold room was cooled until all surfaces in the room were equalized with the ambient temperature, and the warm room was heated until off of its surface had equalized. When you open a sliding door, the cold will flow to the heated side at the bottom of the door, and the heat will flow to the cold side at the top of the door.
But I still think there will be a differential loss of cold as some of it is absorbed by warmer molecules.
And believe it or not, there is friction in air movement.
Ground School for hot air ballooning is much more intense than it is to fly a private plane.
So much more we had to learn that did not apply to winged aircraft.
Did you know that if there is a huge Oak Tree in the middle of large field, and you try to pass over it by only about 20 feet above the tree, that tree will suck the balloon right into it. Exactly the opposite of what one would expect to happen.
The air above a tree is colder, therefore it should cause a balloon to rise, right!
But there are thermodynamics at play here, the cold air is flowing downward through the tree causing a downdraft, and more often than not, this downdraft is more than enough to overcome the slight buoyancy of a hot air balloon traveling at a fixed height across the field.
Again, what happens is exactly the opposite of what you think would happen.
If the air above the tree is colder, this means it is more dense, and therefore the less dense hot air balloon should rise sharply as it passes over the tree. Not So, you get sucked down into the tree.
But I still think there will be a differential loss of cold as some of it is absorbed by warmer molecules.
And believe it or not, there is friction in air movement.
Ground School for hot air ballooning is much more intense than it is to fly a private plane.
So much more we had to learn that did not apply to winged aircraft.
Did you know that if there is a huge Oak Tree in the middle of large field, and you try to pass over it by only about 20 feet above the tree, that tree will suck the balloon right into it. Exactly the opposite of what one would expect to happen.
The air above a tree is colder, therefore it should cause a balloon to rise, right!
But there are thermodynamics at play here, the cold air is flowing downward through the tree causing a downdraft, and more often than not, this downdraft is more than enough to overcome the slight buoyancy of a hot air balloon traveling at a fixed height across the field.
Again, what happens is exactly the opposite of what you think would happen.
If the air above the tree is colder, this means it is more dense, and therefore the less dense hot air balloon should rise sharply as it passes over the tree. Not So, you get sucked down into the tree.
Re: Another Win For Linux
You got to keep in mind how that hot and cold room problem came to my attention. It was randomly dropped into one of our forums by a drive by member. I'm certain he did it as a joke because we never heard from him again. There were no "givens" in his question and no mention of physics nor thermal dynamics. The answer to the question is thus hypothetical as is most science. Nothing on earth exists in a pure state. But, the math behind it shows how perfect it is. The principle involved with the two rooms is one of equilibrium. That translates into entropy theory. The natural forces of the universe we know would stabilize the room temperature to an ideal state. As you point out, it's all theory. Nothing really works that way.
It is at first thought surprising to think about how a hot air balloon would be sucked into a tree. The laws of buoyancy are still valid, of course, but that too is in a perfect world which the earth is not. One of the more amazing aspects of flight is how gliders stay aloft for such a long period of time. They find thermal winds that are exactly the opposite of the oak tree effect. If you find enough of these upward moving winds, you can keep your glider in the air indefinitely. Doesn't seem possible at first thought.
It is at first thought surprising to think about how a hot air balloon would be sucked into a tree. The laws of buoyancy are still valid, of course, but that too is in a perfect world which the earth is not. One of the more amazing aspects of flight is how gliders stay aloft for such a long period of time. They find thermal winds that are exactly the opposite of the oak tree effect. If you find enough of these upward moving winds, you can keep your glider in the air indefinitely. Doesn't seem possible at first thought.
Re: Another Win For Linux
I rode in a Glider one time. It belonged to a club who used the same airport I as using for my initial flying lessons.
The only thing I learned from the experience was, a Glider pilot cannot just go anywhere to fly a glider.
They must know the terrain and all the air currents of a given area, else they will be on the ground in short order.
Jumping back to hot air balloons, if you can stand the cold, you can go any direction you choose in a hot air balloon.
Now most hot air ballooners only fly between 100 and 500 feet, so they are carried the direction of the ground winds. This is fairly safe because you can have a departure point, and most often an established landing zone, unless something really strange happens.
If you look up at the clouds, and there are clouds at two different altitudes, you will see they are moving in slightly different directions. But you have to get way above the clouds to find winds going in the opposite direction. Often so high you need cold winter gear and oxygen, which is why balloon travel isn't the best mode of transportation, hi hi.
Most folks don't realize a hot air balloon is moderately steerable. Not like a car of course, hi hi.
Look at parachutes, they now have those which are fully steerable. But balloons are not quite like that.
What started out probably more than a century ago as spin stabilizers to prevent a balloon from becoming like a spinning top, they learned to use those stabilizers to affect the direction of the balloon slightly.
Then over the years new methods were employed. But it's not like what you think. Like driving on a road, you are still limited to driving on the roadway, but you can change lanes as you move along.
That's about the limit of steerability of a hot air balloon.
For E.g. you are approaching your landing zone in a public park, but you are a little bit too far left of it, and would come down in a subdivision. You can cause the balloon to drift back to the right and get on course again to land at the park landing zone.
They now make hot air balloons with propulsion units to make them more steerable, some are like air jets, some are equipped with electric propellers, etc. I've even seen one that had something under the basket similar to a rudder, hi hi.
The only thing I learned from the experience was, a Glider pilot cannot just go anywhere to fly a glider.
They must know the terrain and all the air currents of a given area, else they will be on the ground in short order.
Jumping back to hot air balloons, if you can stand the cold, you can go any direction you choose in a hot air balloon.
Now most hot air ballooners only fly between 100 and 500 feet, so they are carried the direction of the ground winds. This is fairly safe because you can have a departure point, and most often an established landing zone, unless something really strange happens.
If you look up at the clouds, and there are clouds at two different altitudes, you will see they are moving in slightly different directions. But you have to get way above the clouds to find winds going in the opposite direction. Often so high you need cold winter gear and oxygen, which is why balloon travel isn't the best mode of transportation, hi hi.
Most folks don't realize a hot air balloon is moderately steerable. Not like a car of course, hi hi.
Look at parachutes, they now have those which are fully steerable. But balloons are not quite like that.
What started out probably more than a century ago as spin stabilizers to prevent a balloon from becoming like a spinning top, they learned to use those stabilizers to affect the direction of the balloon slightly.
Then over the years new methods were employed. But it's not like what you think. Like driving on a road, you are still limited to driving on the roadway, but you can change lanes as you move along.
That's about the limit of steerability of a hot air balloon.
For E.g. you are approaching your landing zone in a public park, but you are a little bit too far left of it, and would come down in a subdivision. You can cause the balloon to drift back to the right and get on course again to land at the park landing zone.
They now make hot air balloons with propulsion units to make them more steerable, some are like air jets, some are equipped with electric propellers, etc. I've even seen one that had something under the basket similar to a rudder, hi hi.
Re: Another Win For Linux
I've seen some Steam Punk renditions of hot air balloons which had rudders. I never saw one of those aloft, and I don't know how well it all works. But, yes, I am aware that some maneuverability is possible with a hot air balloon. Something like twenty-five years ago we were visiting my daughter who lived in Colorado Springs at the time. Mom was with us. She saw an ad for balloon rides and it didn't take long for my daughter to arrange it. Apparently there was a waiting list and the launches all depended on the prevailing winds. Mom only had to wait a few days for a spot. She got a certificate attesting to the fact that she officially rode in a balloon and I think they took a picture of her aloft too. It was the thrill of her life, as she said and all for only $65. I looked into the air parks around here and the price is more than double that now. Plus they only operate a few months out of the year. My wife of many years has a fear of heights, which means we'll likely never experience silent flight. We probably won't go up the Arch in St Louis either for that very same reason.
Re: Another Win For Linux
Ha ha ha, what makes you think hot air ballooning is silent?
There are short moments of near silence, but believe me, ear plugs would be in order, hi hi.
Ever used a trigger pull propane torch like used for doing plumbing work?
Remember how noisy it was?
Now multiply that by about 14 to 16 of those all at once at double the noise level for each one.
You can hear those burners on the ground 200 feet below the height of the balloon, hi hi.
I am now terrified of height and freeze on a short ten foot ladder about the six foot point.
But have gone up in the arch several times, it's inside, like an elevator, only more cramped, and it turns angles on the way up.
Scared to death in a bucket truck lift now too.
Ironic, since I used to change lights in 1000 foot tall radio and TV towers, although most of them were only around 500 to 800 feet tall. Still did a couple that were over a 1000 feet. The view is beautiful from up there!
Oh, this was while I was much younger, and still thought I was invincible, hi hi.
As a young kid, I climbed our 100+ foot tall Weiderholt Chimney, and many of the rungs had come loose on the inside, probably rusted off. If I leaned back I could have pulled one out and got killdecated. I did check each one to see which ones were loose on the way up, and marked them with a yellow grease pencil on the top so I knew coming back down which ones were loose.
When we had the top rebuilt, the company who did the work had a round scaffold that fit around the chimney and it could walk up the side of the chimney. On their way up, they would pull what rungs out they could, and cut the rest off with a welding torch, then using a punch, pushed the part in the blocks into the inside of the chimney so they would fall to the bottom. There was a huge door at the bottom of the chimney us kids used to go into in the summer when the boilers were not running and look up. There was also the large duct from the boilers to the chimney, one of CJ's kids braved crawling into once. He came back out black as the ace of spades too.
Ahh, the good old days of mischief and mayhem, hi hi.
There are short moments of near silence, but believe me, ear plugs would be in order, hi hi.
Ever used a trigger pull propane torch like used for doing plumbing work?
Remember how noisy it was?
Now multiply that by about 14 to 16 of those all at once at double the noise level for each one.
You can hear those burners on the ground 200 feet below the height of the balloon, hi hi.
I am now terrified of height and freeze on a short ten foot ladder about the six foot point.
But have gone up in the arch several times, it's inside, like an elevator, only more cramped, and it turns angles on the way up.
Scared to death in a bucket truck lift now too.
Ironic, since I used to change lights in 1000 foot tall radio and TV towers, although most of them were only around 500 to 800 feet tall. Still did a couple that were over a 1000 feet. The view is beautiful from up there!
Oh, this was while I was much younger, and still thought I was invincible, hi hi.
As a young kid, I climbed our 100+ foot tall Weiderholt Chimney, and many of the rungs had come loose on the inside, probably rusted off. If I leaned back I could have pulled one out and got killdecated. I did check each one to see which ones were loose on the way up, and marked them with a yellow grease pencil on the top so I knew coming back down which ones were loose.
When we had the top rebuilt, the company who did the work had a round scaffold that fit around the chimney and it could walk up the side of the chimney. On their way up, they would pull what rungs out they could, and cut the rest off with a welding torch, then using a punch, pushed the part in the blocks into the inside of the chimney so they would fall to the bottom. There was a huge door at the bottom of the chimney us kids used to go into in the summer when the boilers were not running and look up. There was also the large duct from the boilers to the chimney, one of CJ's kids braved crawling into once. He came back out black as the ace of spades too.
Ahh, the good old days of mischief and mayhem, hi hi.
Re: Another Win For Linux
Actually I know the burners on a hot air balloon make a lot of noise. However, I figured after being aloft for a while the burners were mostly off. I guess I misjudged that one.
Truth be told my acrophobic wife and I have been to some extreme heights on rare occasion. I think I might be able to convince her to come along on a trip over the Arc, but there is no way in hell she would go up in a balloon. She insists on an aisle seat when she travels by air too. You have my admiration for climbing a thousand foot tower to change a light bulb. I didn't think there was such a thing. I lived less than ten miles from O'Hare International and no tower over 100' tall was allowed so that I've never seen such a tall tower. They have towers on top of the skyscrapers downtown Chicago. I'm fairly certain that even today I'd not be afraid to crawl up one of those, but I would have to be damned certain that if I slipped I wasn't going anywhere. LOL
The grandest view of the world I ever saw was on top of Mt Evans, Colorado. It was higher than Pike's Peak by a few feet but I'd have to look up the elevation. I'm thinking greater than 14,000 feet. They claimed you could see five states from up there. I probably did, but I could not recognize any of them from that distance.
Truth be told my acrophobic wife and I have been to some extreme heights on rare occasion. I think I might be able to convince her to come along on a trip over the Arc, but there is no way in hell she would go up in a balloon. She insists on an aisle seat when she travels by air too. You have my admiration for climbing a thousand foot tower to change a light bulb. I didn't think there was such a thing. I lived less than ten miles from O'Hare International and no tower over 100' tall was allowed so that I've never seen such a tall tower. They have towers on top of the skyscrapers downtown Chicago. I'm fairly certain that even today I'd not be afraid to crawl up one of those, but I would have to be damned certain that if I slipped I wasn't going anywhere. LOL
The grandest view of the world I ever saw was on top of Mt Evans, Colorado. It was higher than Pike's Peak by a few feet but I'd have to look up the elevation. I'm thinking greater than 14,000 feet. They claimed you could see five states from up there. I probably did, but I could not recognize any of them from that distance.
Re: Another Win For Linux
Small world! I've been to the top of both Pikes Peak and Mt. Evans. and yes Mt. Evans is taller.
Rode the cog train on Pikes Peak, but we drove to the top of Mt. Evans. The engine runs super rich when you get up that high, so almost all the cars back then blew black smoke from the tailpipe out in the parking lot, hi hi.
I guess not enough oxygen for complete combustion?
My uncle Andy is who convinced me to help him on a lower tower job. And he hit the nail on the head with his comments. Once you cross about 35 to 40 feet, it doesn't matter if you are up higher or not, if you fall, you're still dead, hi hi.
I'll be honest with you though, although my uncle only used one harness and clip, I played it safe and used two, and the two I used had separate twin lines inside the sheathing.
The bulbs used back then were huge, and the top one had numerous elements in it. They were replaced when about 1/3 of the elements had failed, which was usually only bit over two or three years, but most companies changed that top one every year.
Those who climb towers to work on the antenna's themselves are a whole different breed. They have to free climb the antenna's themselves with no safety harness per se. Now that is something I would never do, not even back then when I was invincible, hi hi.
It is windy and cold up there, and we do not bring all the lights up with us at once. We instead drop a tether line down to pick up another sack of lamps for the lower lamps, but we do have to carry the top lamp with us all the way, and it was heavy.
Now of course they use small gas filled strobe lamps which can last ten or more years, but they too have three or four separate lamps in them, and some even have six lamps.
What is sad though, is back when I did a few towers, not many though, we were only paid something like 75 bucks for the first tier, another 150 for second tier and third tier, not each, and 250 for doing the top lamp. Basically we made just shy of 500 bucks for doing all the lights on a tower.
Today, they pay 2,500 to 5,000 dollars to replace the lamps, 2,500 for towers under 700 feet, around 850 bucks for 700 to 900 feet, and 5 grand for going over 1000 feet.
The guys who work on the antennas themselves make more than double that amount per tower.
My uncle saw an antenna guy fall and he hit the guy wires on the way down and it cut the fellow in half.
That's when Andy quit. I had quit a few months before then due to taking another inside desk job, hi hi.
Rode the cog train on Pikes Peak, but we drove to the top of Mt. Evans. The engine runs super rich when you get up that high, so almost all the cars back then blew black smoke from the tailpipe out in the parking lot, hi hi.
I guess not enough oxygen for complete combustion?
My uncle Andy is who convinced me to help him on a lower tower job. And he hit the nail on the head with his comments. Once you cross about 35 to 40 feet, it doesn't matter if you are up higher or not, if you fall, you're still dead, hi hi.
I'll be honest with you though, although my uncle only used one harness and clip, I played it safe and used two, and the two I used had separate twin lines inside the sheathing.
The bulbs used back then were huge, and the top one had numerous elements in it. They were replaced when about 1/3 of the elements had failed, which was usually only bit over two or three years, but most companies changed that top one every year.
Those who climb towers to work on the antenna's themselves are a whole different breed. They have to free climb the antenna's themselves with no safety harness per se. Now that is something I would never do, not even back then when I was invincible, hi hi.
It is windy and cold up there, and we do not bring all the lights up with us at once. We instead drop a tether line down to pick up another sack of lamps for the lower lamps, but we do have to carry the top lamp with us all the way, and it was heavy.
Now of course they use small gas filled strobe lamps which can last ten or more years, but they too have three or four separate lamps in them, and some even have six lamps.
What is sad though, is back when I did a few towers, not many though, we were only paid something like 75 bucks for the first tier, another 150 for second tier and third tier, not each, and 250 for doing the top lamp. Basically we made just shy of 500 bucks for doing all the lights on a tower.
Today, they pay 2,500 to 5,000 dollars to replace the lamps, 2,500 for towers under 700 feet, around 850 bucks for 700 to 900 feet, and 5 grand for going over 1000 feet.
The guys who work on the antennas themselves make more than double that amount per tower.
My uncle saw an antenna guy fall and he hit the guy wires on the way down and it cut the fellow in half.
That's when Andy quit. I had quit a few months before then due to taking another inside desk job, hi hi.
Re: Another Win For Linux
My trip to the top of Mt Evans was in a chauffeured limo. I was still in my teens at the time but didn't quite feel invincible yet. LOL Actually I was able to enjoy the trip a lot more because I didn't have to keep my eye on the road. They also told us our carburetor settings and timing had to be changed in order to make the trip. It wasn't worth all the trouble.
I had no idea what those tower monkeys were being paid, but I think they don't get enough for the risk they are taking. I'd not be afraid of the height per se, but my understanding is that there is a lot of swinging and swaying going on at that height. They build sky scrapers to be able to sustain a certain amount of lateral shifting and I'm certain the towers on top of them are even more flexible. I have a feeling that the tower maintenance is or shortly will be done by drones and robots. It's a lot safer not to mention cheaper in the long run.
I had no idea what those tower monkeys were being paid, but I think they don't get enough for the risk they are taking. I'd not be afraid of the height per se, but my understanding is that there is a lot of swinging and swaying going on at that height. They build sky scrapers to be able to sustain a certain amount of lateral shifting and I'm certain the towers on top of them are even more flexible. I have a feeling that the tower maintenance is or shortly will be done by drones and robots. It's a lot safer not to mention cheaper in the long run.
Re: Another Win For Linux
Even though they have guy wires, those towers move back and forth a goodly distance.
On a windy day, they also vibrate like a tuning fork. Heck, they vibrate most of the time.
I know you said you don't have a riding mower, but if you did, while you are out mowing the grass, if you stop the mower and look at the sky, the vibration of the mower makes it look like the sky is moving away from you.
You experience this same affect when the towers are vibrating, even just a little.
Most of the vibration is actually coming to the tower via the guy wires. Some of them can even sing if the wind is just right.
Almost all new towers, and a few that have been modified, are using a new type of lamp socket so a drone could install a new lamp, and/or a person dangling from a helicopter drop line.
You may notice on some of the towers, the lights on the sides are now standing out from the tower a good three to four feet, not connected to the side of the tower like they used to be. This new design was just for possibly using drones, when they become advanced enough to do so.
The OLD original lamps used to be inside of glass housings that had to be unbolted, flipped open, the lamp removed, the new lamp put in its place, the gasket replaced, the lid closed and bolted back down again. It was a project!
The new lamps merely plug in and get a twist. The lamp itself is protected and has a seal already on the bottom of the lamp. Now they have lamps that do not even have an actual electrical connection. They use magnetic coils (transformers) to send the power from the base transformer to the transformer in the lamp. The lamps themselves just slide into a tube is all, that covers about 2/3 the length of the lamp unit. No bolts, screws, or twisting. These are the kind a drone could easily change.
On a windy day, they also vibrate like a tuning fork. Heck, they vibrate most of the time.
I know you said you don't have a riding mower, but if you did, while you are out mowing the grass, if you stop the mower and look at the sky, the vibration of the mower makes it look like the sky is moving away from you.
You experience this same affect when the towers are vibrating, even just a little.
Most of the vibration is actually coming to the tower via the guy wires. Some of them can even sing if the wind is just right.
Almost all new towers, and a few that have been modified, are using a new type of lamp socket so a drone could install a new lamp, and/or a person dangling from a helicopter drop line.
You may notice on some of the towers, the lights on the sides are now standing out from the tower a good three to four feet, not connected to the side of the tower like they used to be. This new design was just for possibly using drones, when they become advanced enough to do so.
The OLD original lamps used to be inside of glass housings that had to be unbolted, flipped open, the lamp removed, the new lamp put in its place, the gasket replaced, the lid closed and bolted back down again. It was a project!
The new lamps merely plug in and get a twist. The lamp itself is protected and has a seal already on the bottom of the lamp. Now they have lamps that do not even have an actual electrical connection. They use magnetic coils (transformers) to send the power from the base transformer to the transformer in the lamp. The lamps themselves just slide into a tube is all, that covers about 2/3 the length of the lamp unit. No bolts, screws, or twisting. These are the kind a drone could easily change.