Richard J Kinch wrote:
Jeff writes:


But the spec sheet says "Average current consumption for 12 VDC
systems over 24-hour period." This is the number of interest to most
boaters, and the proper measure is Amp-Hours.


No it isn't. Current is measured in amps. Amp-hours are not a measure
of current. Nothing could be simpler, and nothing more can really be
debated about it. This is not an oversight, it shows the author is a
fraud or a fool.

Yes current is measured in amps. But to be useful you need another
measurement, time. That gives amp hours. Battery capacity is rated in
amp hours, usually at a 20 amp rate. If I want to know what size
batteries I need to supply my house load I measure the current used by
each device, i.e. lights, fans, reffer, etc and determine the
approximate time used by each device and compute total amp hours load
over a 12 or 24 hour period. Multiply the amp hour load by two and use
that size battery. So while you are correct that the measurement of
current is amps, if a manufacturer list a spec of 54 amp hours usage in
24 hours it tells me a lot more than just 4 amps compressor draw.
krj


While R-134a is safer than other refrigerants it is still illegal to
vent and difficult to handle properly. Its toxic and corrosive, and
anyone who has had a larger refrigeration system serviced understands
from the amount of gear the technician hauled down to the boat that
these are not trivial procedures. A CO2 system, on the other hand,
can be vented freely, and recharged with a simple cartridge. No
license or special training is required. If this does not look like a
significant advantage to you, then you should not be posting in a
"cruising" forum.


You are in your typical error about the "simple cartridge" as a
comparative advantage. A cartridge for CO2 at 1000 psi is not "simple"
in comparison to ordinary refrigerants at 100 psi. Whatever
"simplicity" advantage you are imagining, it inheres more in the usual
refrigerants. The fact that it is *harder* to store CO2 in a cartridge,
yet this is claimed as an "advantage", just further shows the stupidity
and/or deceit of the claims.

"Vented freely" is a political, not a technical advantage.

CO2 is lousy refrigerant for all but a few unusual applications, because
of its material properties, such as high saturation pressure, and low
critical temperature. It does not fit ordinary refrigeration
applications, and it cannot be engineered to do so. It only "works" as
a political force-fit, like when Coca-Cola wants PR for the Athens
Olympics.


But you didn't base your argument on weighing pros and cons, you
claimed that CO2 refrigeration was impossible, a hoax, and likened it
to "perpetual motion machines." Thank you for admitting you were
wrong, however obliquely.


No, I said that this "tropikool" gadget amounts to perpetual motion
claims, and that CO2 efficiency was a hoax, that efficiency (relative
to, say, R-134a) was impossible. That politicians let you vent CO2 but
not R-134a says nothing about their respective material properties as a
refrigerant. I never said CO2 refrigeration was impossible in
principle, just impossible that it would be practical in ordinary
applications.

You might as well claim that a steam engine is better than gasoline
internal combustion, because we can fuel it with grass clippings instead
of that expensive petroleum. Yes, it is possible to get steam power
from grass clippings, but it is impossible that it could work better
than a gasoline engine.

Now I will admit I was wrong, in that if a politician holds a gun to my
head and insists that CO2 is all you seem to be claiming, then yes, CO2
is just great. Since we still haven't reached quite that point, I
regret I must maintain that the OP points to a product that is a phony
based on either fraud or foolishness.

Richard J Kinch wrote:

Jeff writes:


But the spec sheet says "Average current consumption for 12 VDC
systems over 24-hour period." This is the number of interest to most
boaters, and the proper measure is Amp-Hours.



No it isn't. Current is measured in amps. Amp-hours are not a
measure of current. Nothing could be simpler, and nothing more can
really be debated about it. This is not an oversight, it shows the
author is a fraud or a fool.

Yes current is measured in amps. But to be useful you need another
measurement, time. That gives amp hours. Battery capacity is rated in
amp hours, usually at a 20 amp rate. If I want to know what size
batteries I need to supply my house load I measure the current used by
each device, i.e. lights, fans, reffer, etc and determine the
approximate time used by each device and compute total amp hours load
over a 12 or 24 hour period. Multiply the amp hour load by two and use
that size battery. So while you are correct that the measurement of
current is amps, if a manufacturer list a spec of 54 amp hours usage
in 24 hours it tells me a lot more than just 4 amps compressor draw.
krj

Ya know, this thread keeps gettin sillier and sillier. Amp-hours, if
anyone cares to look it up instead of just flappin, is a measurement of
current. And I defy anyone, including Mr. Kinch, to find a way for
current to flow without time. If current was without time, it could not
possibly *be* current. It would then be reduced to "...potential for
current to flow, which when flowing would be measured in amp-hours..."
Current is a verb, it defines an action. Without the action, there's no
flow. Without the flow there's no "amps", which is always measured
against a unit of time - the convention being hours (notice I said
'convention'- you could use any time measurement, days, U-seconds,
etc.). It cannot be measured without time - ever. Therefore, "amps" by
itself, does not describe anything. You could say there is a measurement
of an *instantaneous current* but that would still be just a snapshot of
the presently measured current-against-time. Amp-hours is and has been
the correct term because a "1 amp" device is defined by convention as a
device that passes a current of 1 amp during the course of an hour. The
term "1 amp" is simply a contraction for "device that passes 1 amp of
current during the period of one hour" Now, isn't that a mouthful?
Jeesh! The engineers and tech's of old used to actually *say*
"amp-hours" when describing current, and all my old electronics
textbooks use that term exclusively.

So if Mr. Kinch wants to call all my electronics professors frauds or
fools, so be it. But then I'll challenge him to come over and put his
instruments where his mouth is and show us all how he manages to measure
"amps" without time for the electrons to flow.

Or was that holes flowing... hmmm...

Sailaway wrote:
....

Ya know, this thread keeps gettin sillier and sillier. Amp-hours, if
anyone cares to look it up instead of just flappin, is a measurement of
current. And I defy anyone, including Mr. Kinch, to find a way for
current to flow without time. If current was without time, it could not
possibly *be* current. It would then be reduced to "...potential for
current to flow, which when flowing would be measured in amp-hours..."
Current is a verb, it defines an action. Without the action, there's no
flow. Without the flow there's no "amps", which is always measured
against a unit of time - the convention being hours (notice I said
'convention'- you could use any time measurement, days, U-seconds,
etc.). It cannot be measured without time - ever. Therefore, "amps" by
itself, does not describe anything. You could say there is a measurement
of an *instantaneous current* but that would still be just a snapshot of
the presently measured current-against-time. Amp-hours is and has been
the correct term because a "1 amp" device is defined by convention as a
device that passes a current of 1 amp during the course of an hour. The
term "1 amp" is simply a contraction for "device that passes 1 amp of
current during the period of one hour" Now, isn't that a mouthful?
Jeesh! The engineers and tech's of old used to actually *say*
"amp-hours" when describing current, and all my old electronics
textbooks use that term exclusively.

Sorry, I don'[t think you have it quite right. "Current" is an
instantaneous rate of charge flow. Although formally defined in terms
of forces in wires, it is better understood as a change in charge, as
in coulombs/second. Since Coulombs can be thought of as a number of
electrons (6.24E+18), Amps are "electrons per second" ignoring the
constant factor. Amps-hours thus represent a number of electrons.
However, the spec sheet said "Average current consumption for 12 VDC
systems over 24-hour period" which is "Amp-hours/day" - for some
reason Kinch keeps ignoring this even though is is clearly stated.
This is measure of charge flow, simply scaled up by 24 from amperes.


So if Mr. Kinch wants to call all my electronics professors frauds or
fools, so be it. But then I'll challenge him to come over and put his
instruments where his mouth is and show us all how he manages to measure
"amps" without time for the electrons to flow.

Measuring something is different from stating its instantaneous
property. Velocity is stated for a moment in time, but is real hard
to measure without considering a change in position over time, or by
using some other technique that considers time.



Or was that holes flowing... hmmm...

Jeff said:
Sorry, I don'[t think you have it quite right. "Current" is an
instantaneous rate of charge flow. Although formally defined in terms
of forces in wires, it is better understood as a change in charge, as
in coulombs/second. Since Coulombs can be thought of as a number of
electrons (6.24E+18), Amps are "electrons per second" ignoring the
constant factor. Amps-hours thus represent a number of electrons.
However, the spec sheet said "Average current consumption for 12 VDC
systems over 24-hour period" which is "Amp-hours/day" - for some
reason Kinch keeps ignoring this even though is is clearly stated. This
is measure of charge flow, simply scaled up by 24 from amperes.

snip


Measuring something is different from stating its instantaneous
property. Velocity is stated for a moment in time, but is real hard
to measure without considering a change in position over time, or by
using some other technique that considers time.


You've said (pretty obliquely) some of the same thing ("electrons per
second"), and I agree with your statement about measurement being
different than describing an instantaneous property.
Current is flow. Flow is not stagnant. Flow cannot be anything else
but flow. For flow to happen in this case, electrons have to move. When
they move, it is called "current". Think of a river - can "current" flow
without movement? You can describe the amount of electrons existing in a
conductor at any one instant in time as a snapshot of an amount of
electrons existing in a conductor, but that amount is the result of the
electrons having flowed through that part of the conductor during some
amount of time however small or large. Just measuring or calculating the
number of electrons present in a conductor is not a measure of current
in and of itself, because current is a measure or calculation of the
number of electrons having flowed through a conductor during a given
specific amount of time.

What you are describing is the *rate* of flow as a snapshot of some
instant in time. But to get that snapshot of the rate of flow, you must
first have current, measured in amp-hours. What you alluding to is not a
measurement, it is a description of a rate of measurement at one
instant. Mr. Kinch talked about a piece of equipment should be rated at
(x) amps, but the term *amps* is in this case a *new terminology*
contraction for amp-hours, or it wouldn't make any sense. We all assume,
consciously or unconsciously, when reading a current rating listed on
any equipment when listed as *amps* to actually be amps-per-hour (the
*rate*) which is the current standard convention.
The time used for your measurement, however, is irrelevant, it is just a
way to determine how many electrons have flowed through the conductor
during that time. So if you used average current over one hour, or one
day, or one year, etc., you still have the same exact same type of
measurement; amps-per-whatever. But average measurement does not
describe what the flow is at any one instant in time, which is what you
were alluding to.
Electrical "pressure" is the old terminology for voltage, described as
"potential". This is not current, but influences current as described by
ohm's law.
Charge is a different entity entirely and is not current.
Velocity is not current, but can influence current. The term can also
seem confusing. If you have a large diameter pipe and have 1 gallon per
hour of water flowing through it, and you have a very small diameter
pipe and have 1 gallon per hour flowing through it you will have two
very different velocities. But if current is the measurement of
units-of-something-per-time, then the *current* is the same in both
pipes, although the *pressure* will necessarily be different (just like
ohm's law). But if the velocity of current, that is, if electrons are
limited in the actual speed each can flow through a given conductor
regardless of pressure (IE: speed of light in a perfect conductor), then
the number of electrons that can flow through a conductor in a given
time is limited at least by the size of the conductor, regardless of the
pressure (voltage). So *velocity* can be an imprecise term to describe
current if you label the amount of current flow as speed of flow (speed
of each electron moving), rather than the total number of
electrons-per-unit-of-time. Of course, exceeding a conductor's ability
to pass a certain number of electrons in a given amount of time will
result in excessive heat which may result in damage, hence the need to
describe a conductor's ability to handle a specific *rate* of current
flow. Most conductors will destruct due to heat before actually
exceeding its max rate of flow of electrons. That is why cooling a
conductor allows more current to be applied through it before self
destructing.
When measuring current with a meter, all U.S. meters that I have seen
and used measure in amps per hour averaged. Meters cannot take a
snapshot in time, because no matter how short the cutoff, it is still time.
If you'd like, you are invited over to look at any number of textbooks
I have (several lockers full) that will describe it for you more
eloquently and completely than I will here. Although my textbooks are
written in the "old" language of electronics - you know; amp-hours,
cycles per second, etc.

Sailaway writes:

Amp-hours, if
anyone cares to look it up instead of just flappin, is a measurement of
current.

No. Amp-hours is a unit of charge. Not current.

Your post is a schizoid rant of physical gibberish.

So if Mr. Kinch wants to call all my electronics professors frauds or
fools, so be it.

If you are claiming to be consulting authorities, I suspect the problem is
your muddled misunderstanding of them.

That's Dr, not Mr, by the way, when it comes to engineering and physics.

Mr. Kinch foamed thusly:
Your post is a schizoid rant of physical gibberish.

Ya caught me!

I've always believed if you can't dazzle 'em with brilliance, then
baffle 'em with bull****.

Have a nice day.