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  1. #40
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    Quote Originally Posted by WAYNE3298 View Post
    The statement I liked was "if you reach the end of space what is on the other side". Another one said what is electricity and one guy raised his hand to give him an answer. The prof yelled "the smartest person in the world doesn't know what electricity is and your going to tell me". He was really a fun person and it made sense when he explained what he meant.

    Not wanting to exactly go there but I seem to remember an explanation of that question was (and maybe just my mindset in some mid 60's chemical abyss) but space being visualized as living on the film of a bubble where inside the bubble is empty time and empty space. So in my little rocket ship I simply glide on film of the bubble and never reach the end.
    I also remember reading in a book by the healer Edgar Cayce was similar to, Man demands a beginning so here's one. No end in sight,
    Give me a relay with big enough contacts, and I'll run the world!

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  2. #41
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    hvacker,
    Something you said earlier got me to thinking that it may be that space doesn't have a zero point (an origin). What little we know about space overwhelms me and apparently we know very little.

  3. #42
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    Quote Originally Posted by shellkamp View Post
    I'm certainly not speaking of theoretical physics here. So long as that fan is running and airflow is not fighting gravity (going up) - the flow will never actually get to zero.

    Sent from my SCH-I545 using Tapatalk

    Why not?
    When air leaves a fan or whatever the source, the fan horse power energy immediately begins transforming to low grade heat. The fan air is confronted with stationary air in the atmosphere. All mechanical energy becomes heat.
    In a piping system, every brake HP is transforms into low grade heat in the system and has to be accounted for as heat added. An advantage in a heat system but not in a cooling sys.
    The only initial energy in our fan system comes from is what's being added by the fan/motor and that will degrade into heat quickly and air motion will stop.
    If we remove any ducting we should expect any air motion to stop even sooner because the air is dispersed over a larger area.
    It's all about what we all know about motion. Things keep going unless acted upon by another force. With our fan the opposing force is the existing air and friction. If it didn't, this would be a very windy planet.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

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  4. #43
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    Quote Originally Posted by hvacker View Post
    Why not?
    When air leaves a fan or whatever the source, the fan horse power energy immediately begins transforming to low grade heat. The fan air is confronted with stationary air in the atmosphere. All mechanical energy becomes heat.
    In a piping system, every brake HP is transforms into low grade heat in the system and has to be accounted for as heat added. An advantage in a heat system but not in a cooling sys.
    The only initial energy in our fan system comes from is what's being added by the fan/motor and that will degrade into heat quickly and air motion will stop.
    If we remove any ducting we should expect any air motion to stop even sooner because the air is dispersed over a larger area.
    It's all about what we all know about motion. Things keep going unless acted upon by another force. With our fan the opposing force is the existing air and friction. If it didn't, this would be a very windy planet.
    How about we think of it this way:

    Since we're talking about airflow through an airtight pipe, then at the fan outlet into the pipe, there will be an increase in pressure from the fan inlet, yes?

    Now, for the sake of simplicity, we'll say that the air at the pipe's termination is of the same density as the fan inlet.

    If there is a pressure difference between two points, air will flow. Period.

    If, for some reason, there was no pressure difference, then there would be no flow and thus no friction loss.

    Friction loss requires flow to develop, wouldn't you agree?

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  6. #44
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    We all agree the fan puts air into the duct. If the duct is air tight and the air doesn't come out the other end of the duct where does it go?

  7. #45
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    Quote Originally Posted by WAYNE3298 View Post
    We all agree the fan puts air into the duct. If the duct is air tight and the air doesn't come out the other end of the duct where does it go?
    The air doesn't go anywhere mystical. The mechanical energy is transformed into low grade heat. Shape shifted.
    If I am driving a car (mechanical energy) and on a flat road, dead flat, and I put the tranny in N and turn off the motor I will stop because the mechanical energy is transformed to heat. Air resistance and wheel friction all become heat.
    There will be a point in the duct where there isn't enough fan HP to push the column of air anymore.
    How do I know this? SWAG method.
    If the thoughts are the air will continue to push with no accounting for fan hp you are close to perpetual motion. We know perpetual motion is against the law.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  8. #46
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    You removed the driving force on the car which is mechanical energy not simply heat. That is the same as turning the fan off. The air pressure is not pure heat energy. By your theory if the pipe is heated an ENDLESS supply of air would come out the end even with the fan off. If you can turn 100% of the air supplied into heat energy you can turn the same heat energy back into airflow.

  9. #47
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    When physicists come up with a newfangled formula, they put in extreme variables to see how the equation will respond. Those extreme variables are: One, zero, and infinity.

    In the case of your airflow question, and using the above parameters, let's increase the density of your air to equal that of water.

    Now let's fill the entire hose or duct with water. Of course we are making assumptions like there is no expansion or contraction in this hose, pipe, or duct.

    If pressure is applied at one end, do you think you will or will not [eventually] see an increase of pressure at the other end?

    Seems I've heard that water does not compress. It may at some level not discernible with simple instruments, but that is a topic for another discussion.


    Quote Originally Posted by hvacker View Post
    The air doesn't go anywhere mystical. The mechanical energy is transformed into low grade heat. Shape shifted.
    If I am driving a car (mechanical energy) and on a flat road, dead flat, and I put the tranny in N and turn off the motor I will stop because the mechanical energy is transformed to heat. Air resistance and wheel friction all become heat.
    There will be a point in the duct where there isn't enough fan HP to push the column of air anymore.
    How do I know this? SWAG method.
    If the thoughts are the air will continue to push with no accounting for fan hp you are close to perpetual motion. We know perpetual motion is against the law.

  10. #48
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    When our pump or fan energy in our duct or a pipe confronts a column of fluid or air, and it does, the fan/pump energy will be consumed/transformed into heat. All of it.
    That heat energy can be accounted for. Example: In a chilled water system each brake HP must be offset by 1/5 ton of refrigeration. I had to look through my stuff to find the engineer's numbers. This is from a Kele engineer Mr. Gill Avery PE.
    2545 BTU/HP
    _________________= 1/5 Ton/HP
    12000 BTU/Ton
    Best I can write it w/o a math app.

    For air it's about 1 HP per 4000 CFM This is from memory but you get where I'm going


    All mechanical or Work, power/motion, if confronted by a resistance will become heat. We remember from science 101 that energy can't be created or destroyed, only changed.
    The resistance is the existing air in the duct or the water in a pipe.
    Even w/o a duct or pipe the air/water would stop moving. This is obvious so doesn't need to be said.
    The energy added to an air duct or pipe is accounted for in any advanced load calc program like Manual J.
    If this didn't happen we would experience perpetual motion.
    It's easy to understand "Pump head" in a vertical pipe. The pump runs out of energy.
    I don't see any difference in a horizontal pipe only what's called "Transport power." A pump/fan will only do so much.
    I rest my case. Perry Mason
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  11. #49
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    Quote Originally Posted by hvacker View Post
    When our pump or fan energy in our duct or a pipe confronts a column of fluid or air, and it does, the fan/pump energy will be consumed/transformed into heat. All of it.
    That heat energy can be accounted for. Example: In a chilled water system each brake HP must be offset by 1/5 ton of refrigeration. I had to look through my stuff to find the engineer's numbers. This is from a Kele engineer Mr. Gill Avery PE.
    2545 BTU/HP
    _________________= 1/5 Ton/HP
    12000 BTU/Ton
    Best I can write it w/o a math app.

    For air it's about 1 HP per 4000 CFM This is from memory but you get where I'm going


    All mechanical or Work, power/motion, if confronted by a resistance will become heat. We remember from science 101 that energy can't be created or destroyed, only changed.
    The resistance is the existing air in the duct or the water in a pipe.
    Even w/o a duct or pipe the air/water would stop moving. This is obvious so doesn't need to be said.
    The energy added to an air duct or pipe is accounted for in any advanced load calc program like Manual J.
    If this didn't happen we would experience perpetual motion.
    It's easy to understand "Pump head" in a vertical pipe. The pump runs out of energy.
    I don't see any difference in a horizontal pipe only what's called "Transport power." A pump/fan will only do so much.
    I rest my case. Perry Mason
    As in the geico commercials: "that's not how it works."

    You're talking about heat being added to the air/water from operation of the pump/fan, you're not offsetting CFM for heat.

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  12. #50
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    Quote Originally Posted by BBeerme View Post
    When physicists come up with a newfangled formula, they put in extreme variables to see how the equation will respond. Those extreme variables are: One, zero, and infinity.

    In the case of your airflow question, and using the above parameters, let's increase the density of your air to equal that of water.

    Now let's fill the entire hose or duct with water. Of course we are making assumptions like there is no expansion or contraction in this hose, pipe, or duct.

    If pressure is applied at one end, do you think you will or will not [eventually] see an increase of pressure at the other end?

    Seems I've heard that water does not compress. It may at some level not discernible with simple instruments, but that is a topic for another discussion.


    Your example isn't equal as your describing a closed system where pressure is added to to it. Your mention of water being non-compressible does apply to your closed system as far as pressure only. A static system. All pump power is consumed adding pressure. If you want to move that water around in a loop, all the resistances in the system apply and consume the power. Dynamic system. The terms static and velocity apply.

    Our talk was about an open system (dynamic or moving)and what happens to pump/fan power.
    You know my point is the power is consumed by the resistance in the duct/pipe friction and the added weight of the added water by pump displacement. In the case of air, the added air from displacement is compressed by the existing air. In both cases the motor energy becomes heat low grade heat.
    I use the term "Low grade heat" as heat that's not easily reclaimed.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

  13. #51
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    Have you considered how nitrogen is removed from an airstream and stored in liquid form? Compressed air is introduced into the nitrogen production system and eventually reaches the turbo expander which removes most of the energy from the air. This process reduces the air temperature from around 300F to around -360F. In spite of this the components of the air are driven thru the system by the pressure introduced by the compressor which is usually about 125 PSIG. The air doesn't disappear but is cooled to the point that it's components are liquefied and fall out in separate elevations of the precip tower. Even with that much energy removed from the air there is some energy remaining or the concept of absolute zero temperature is false because at absolute zero all motion ceases. A pipe with low pressure air can't even come close to the heat removed by this process.

  14. #52
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    Quote Originally Posted by shellkamp View Post
    As in the geico commercials: "that's not how it works."

    You're talking about heat being added to the air/water from operation of the pump/fan, you're not offsetting CFM for heat.

    Sent from my SCH-I545 using Tapatalk


    Ya, but that is how it works.
    Not sure I understand your post about "Not offsetting CFM for heat"
    All kinetic energy becomes heat. I doesn't matter if we are referring to block tight or wide open fan operation. Doesn't matter if were moving air or not.
    The energy of motion (CFM) confronts the resistance in the duct consisting of duct friction(all components) and the air already in the duct and consumes the fan power. The motion of the air (CFM) kinetic energy will give way to the resistances in the system.
    To keep air moving in the duct, fan power has to be constantly added or the air will stop.
    Give me a relay with big enough contacts, and I'll run the world!

    You can be anything you want......As long as you don't suck at it.

    If a person wants to create a machine that will be more likely to fail...Make it complicated.

    USAF 98 Bomb Wing 1960-66 SMW Lu49

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