Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?

On 25 Jan 2006 18:09:26 -0800, wrote:

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning.
snip
My question is: what causes some people to have steam and others not?

If the stack is above or below approximately 250°F.


-zero

wrote in message
....
Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise it
is not steam. To be picky, steam is invisible. It is a vapor and cannot be
seen at all. What you are seeing is condensation that is now visible in the
cold air.

When fuel is burned, there are products of combustion that are given of into
the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some will
exit and not be seen. High efficiency units are sending the water vapor out
a shorter length of PVC and you see more of it.

On 25 Jan 2006 18:09:26 -0800, wrote:

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?

What you see is not actually steam, but is a release, due to a bad
connection, of leakage from the nuclear heater that is used in some
new installations. Do not allow your children to go outside when it
is visible, or for four hours afterwards.


Remove NOPSAM to email me. Please let
me know if you have posted also.

wrote:
Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


Humidifiers?

--
Thank you,


CL Gilbert
"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

Edwin Pawlowski wrote:

wrote in message
...

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?



I'm glad you put "steam" in parenthesis, because, as you already surmise it
is not steam. To be picky, steam is invisible. It is a vapor and cannot be
seen at all. What you are seeing is condensation that is now visible in the
cold air.

When fuel is burned, there are products of combustion that are given of into
the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some will
exit and not be seen. High efficiency units are sending the water vapor out
a shorter length of PVC and you see more of it.

Let me correct your argument a bit. Firstly these are parentheses ().
These are quotation marks '' "

The answer to the OP's question is that the RH of the output from the
condensing furnace is 100%. It is at saturation, otherwise it wouldn't
be a condensing furnace. The dew point temp OTOH is only slightly lower
than the temperature of the gas. A drop of only a few degrees will cause
further condensation of moisture out of the gas.

With the noncondensing furnace, however, the dew point is several
degrees lower than the temp of the output gas, and by the time the flue
gas temp drops sufficiently to reach dew point the water vapor within it
has dispersed, mixing with the ambient air. IOW the RH has dropped
simultaneously with the drop in temperature, and thus when the furnace
is full up to speed no condensation can occur. Your last point BTW is
completely incorrect; the high efficiency unit is sending *less* water
vapor out. Even so, some of what it does send out condenses before it
gets far from the outlet, again, because its dew point is much closer to
its saturated temp than in the low efficiency unit output.

Richard Perry

"RP" wrote in message
Let me correct your argument a bit. Firstly these are parentheses ().
These are quotation marks '' "

Duh!

Your last point BTW is completely incorrect; the high efficiency unit is
sending *less* water vapor out. Even so, some of what it does send out
condenses before it gets far from the outlet, again, because its dew
point is much closer to its saturated temp than in the low efficiency unit
output.

Would they not both send out the same amount of vapor per ccf of gas burned?
Your explanation is more detailed than mine though. Thanks.

Steam is a vapor, but it isn't invisible. Clouds and fog are a vapor, but
they can be seen. What about the steam that come off of ice when the sun
hits it?

"Edwin Pawlowski" wrote in message
m...

wrote in message
...
Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise
it
is not steam. To be picky, steam is invisible. It is a vapor and cannot
be
seen at all. What you are seeing is condensation that is now visible in
the
cold air.

When fuel is burned, there are products of combustion that are given of
into
the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some
will
exit and not be seen. High efficiency units are sending the water vapor
out
a shorter length of PVC and you see more of it.

Bob wrote:
Steam is a vapor, but it isn't invisible. Clouds and fog are a vapor, but
they can be seen. What about the steam that come off of ice when the sun
hits it?

That's not steam. Steam IS invisible, otherwise it's not steam. It's
mist, fog or water vapor, but it's not steam.

http://en.wikipedia.org/wiki/Steam

There are only three states, solid, liquid, and gas. Mist, fog, water vapor,
and steam are all H2O in a gas state. Depending on their temperature and
percent of concentration, they can all be seen.

"Larry Bud" wrote in message
oups.com...

Bob wrote:
Steam is a vapor, but it isn't invisible. Clouds and fog are a vapor,
but
they can be seen. What about the steam that come off of ice when the sun
hits it?

That's not steam. Steam IS invisible, otherwise it's not steam. It's
mist, fog or water vapor, but it's not steam.

http://en.wikipedia.org/wiki/Steam

Edwin Pawlowski wrote:
"RP" wrote in message

Let me correct your argument a bit. Firstly these are parentheses ().
These are quotation marks '' "


Duh!


Your last point BTW is completely incorrect; the high efficiency unit is
sending *less* water vapor out. Even so, some of what it does send out
condenses before it gets far from the outlet, again, because its dew
point is much closer to its saturated temp than in the low efficiency unit
output.


Would they not both send out the same amount of vapor per ccf of gas burned?
Your explanation is more detailed than mine though. Thanks.

Well no, they wouldn't. The condensing furnace diverts some of the
moisture content of the gas out the condensate line.
Your welcome.

Richard Perry

You are wrong, natural gas and propane do NOT contain water or the pipes
would have ice blocking the pipes where the water accumulates in cold
weather. However both are hydrocarbons, they contain hydrogen and carbon.
When burned with oxygen they form carbon dioxide and water (hydrogen oxide).
It is this water vapour that you see condensing outside the furnace chimney
or vent. This is the same process that forms condensation at your car's
exhaust pipe or water dripping from the exhaust pipe and the con-trails that
leave white streaks behind jet airplanes.

"Edwin Pawlowski" wrote in message
m...

wrote in message
...
Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise
it
is not steam. To be picky, steam is invisible. It is a vapor and cannot
be
seen at all. What you are seeing is condensation that is now visible in
the
cold air.

When fuel is burned, there are products of combustion that are given of
into
the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some
will
exit and not be seen. High efficiency units are sending the water vapor
out
a shorter length of PVC and you see more of it.

Bob wrote:

There are only three states, solid, liquid, and gas. Mist, fog, water vapor,
and steam are all H2O in a gas state. Depending on their temperature and
percent of concentration, they can all be seen.

Vapor in engineering terms designates a gaseous state of matter. In that
state water exists as steam, and is invisible.
Vapor in common terms designates a mixture of gas(es) and condensed
droplets and/or other particulates.
When you see water vapor rising from a pot of boiling water it is small
condensed water droplets (water in a liquid state) that you see. The
steam from which these condense is however invisible.

Richard Perry



"Larry Bud" wrote in message
oups.com...

Bob wrote:

Steam is a vapor, but it isn't invisible. Clouds and fog are a vapor,

but

they can be seen. What about the steam that come off of ice when the sun
hits it?

That's not steam. Steam IS invisible, otherwise it's not steam. It's
mist, fog or water vapor, but it's not steam.

http://en.wikipedia.org/wiki/Steam

EXT wrote:

You are wrong, natural gas and propane do NOT contain water or the pipes
would have ice blocking the pipes where the water accumulates in cold
weather. However both are hydrocarbons, they contain hydrogen and carbon.
When burned with oxygen they form carbon dioxide and water (hydrogen oxide).

While you are technically correct, I just wanted to note that as I read
it he implied exactly that, i.e. when he referred first to combustion
byproducts. The statement "gas contains moisture" is subject to
interpretation Take everything in context. One might call this
*latent moisture*. OTOH, there is some actual trace moisture present in
the gas mixture even before combustion, so let's go ahead and dot some
more i's while where at it. BTW, I have encountered frozen gas lines,
FWIW. Not many, but a few.

Richard Perry

It is this water vapour that you see condensing outside the furnace chimney
or vent. This is the same process that forms condensation at your car's
exhaust pipe or water dripping from the exhaust pipe and the con-trails that
leave white streaks behind jet airplanes.

"Edwin Pawlowski" wrote in message
m...

wrote in message
...

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise

it

is not steam. To be picky, steam is invisible. It is a vapor and cannot

be

seen at all. What you are seeing is condensation that is now visible in

the

cold air.

When fuel is burned, there are products of combustion that are given of

into

the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some

will

exit and not be seen. High efficiency units are sending the water vapor

out

a shorter length of PVC and you see more of it.

Your welcome.

Richard Perry


Well, no. To be perfectly correct, it would be "you're welcome",
contraction for "you are". "Your" is a possessive pronoun.

Bob

EXT wrote:

When burned with oxygen they form carbon dioxide and water (hydrogen oxide).

Wouldn't that be dihydrogen oxide? Hydrogen Oxide would be HO. Water is
H2O.

Bob

"Bob" wrote in message
...
There are only three states, solid, liquid, and gas. Mist, fog, water
vapor,
and steam are all H2O in a gas state. Depending on their temperature and
percent of concentration, they can all be seen.


Mist and fog are not gases. They are liquid.

Could be!!!!!!!!!!!!!

"RobertM" wrote in message
...
EXT wrote:

When burned with oxygen they form carbon dioxide and water (hydrogen
oxide).

Wouldn't that be dihydrogen oxide? Hydrogen Oxide would be HO. Water is
H2O.

Bob

Well........... being technically correct. With natural gas there are three
types of gas used in old cities, primarily because of the presence of cast
iron pipes that are sealed with oakum and lead the same way that cast iron
drain pipes are sealed. Most areas with steel or plastic pipes are supplied
with dry gas, any water in it will be accidental such as in new piping or
where the line is punctured letting water in. Old areas are supplied with
"humidified" gas where they add some steam to keep the oakum moist, or they
add oil vapour to do the same job. In older cities you will see small iron
fittings in the street or sidewalk that say "drip". These are not a comment
on the local people but a low point in the underground piping where water or
oil accumulates from condensing of the injected steam or oil. At regular
intervals, the gas utility will access these drips to pump out excess water
or oil.


"RP" wrote in message
...


EXT wrote:

You are wrong, natural gas and propane do NOT contain water or the pipes
would have ice blocking the pipes where the water accumulates in cold
weather. However both are hydrocarbons, they contain hydrogen and
carbon.
When burned with oxygen they form carbon dioxide and water (hydrogen
oxide).

While you are technically correct, I just wanted to note that as I read
it he implied exactly that, i.e. when he referred first to combustion
byproducts. The statement "gas contains moisture" is subject to
interpretation Take everything in context. One might call this
*latent moisture*. OTOH, there is some actual trace moisture present in
the gas mixture even before combustion, so let's go ahead and dot some
more i's while where at it. BTW, I have encountered frozen gas lines,
FWIW. Not many, but a few.

Richard Perry

It is this water vapour that you see condensing outside the furnace
chimney
or vent. This is the same process that forms condensation at your car's
exhaust pipe or water dripping from the exhaust pipe and the con-trails
that
leave white streaks behind jet airplanes.

"Edwin Pawlowski" wrote in message
m...

wrote in message
...

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise

it

is not steam. To be picky, steam is invisible. It is a vapor and cannot

be

seen at all. What you are seeing is condensation that is now visible in

the

cold air.

When fuel is burned, there are products of combustion that are given of

into

the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will
be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some

will

exit and not be seen. High efficiency units are sending the water vapor

out

a shorter length of PVC and you see more of it.

RobertM wrote:

Your welcome.

Richard Perry


Well, no. To be perfectly correct, it would be "you're welcome",
contraction for "you are". "Your" is a possessive pronoun.

Have a banana.

Richard Perry

? wrote:

On 2006-01-25 21:09:26 -0500, said:

My question is: what causes some people to have steam and others not?


Stack temperature.

If your clay-lined stack is cool enough to condense the water vapor
before it exits the chimney ??no "steam." If their metal stacks are hot
enough to keep the exhaust temperature above the dew point until it gets
outside ? then you have "steam."

You made that up.

Richard Perry



(BTW, "steam" is an invisible gas. What you're seeing is water
vapor...tiny droplets of liquid.)

RP

The Colonel is correct. The products of combustion of gas (or any
hudyocarbon) are Carbon Dioxide and WATER VAPOR. (With incomplete
combustion you would also have some soot, which is unburned carbon, and
some Carbon Monoxide, which is combustable.) If the stack
temperature (flue temperature) is low enough, the Relative Humidity
will hit 100%. That means some of the water vapor will condense into
liquid water vapor droplets. This is what you see coming out of the
chimney. If the flue gas is too hot, the water vapor will mix with the
dry air outside before condensation can occ. Or if it occurs, the
vapor clout will be so dilute you won't be able to see it.

Stretch

To All,

Please excuse my mispelling of Hydrocarbon in my previous post.

Stretch

Ok. I see I have created quite a war here. So why is it that My huge
boiler puts out no vapour, steam, "cloud", but my neighbors wimpy water
heater puts out a huge "cloud". Furthermore, lets say I like the
cloud, what can I do to cause the cloud when I install a new water
heater with b vent? What can be done to avoid the visible cloud with b
vent on a cold day? Thanks

wrote in message
oups.com...
Ok. I see I have created quite a war here. So why is it that My huge
boiler puts out no vapour, steam, "cloud", but my neighbors wimpy water
heater puts out a huge "cloud". Furthermore, lets say I like the
cloud, what can I do to cause the cloud when I install a new water
heater with b vent? What can be done to avoid the visible cloud with b
vent on a cold day? Thanks


Your huge heater is putting out the vapor, but it may be condensing inside
the chimney and just dropping down to the ground inside. Most chimneys have
a longer run than the high efficiency heaters that go out the side of the
house.

Actually, adjective.

"You", "it", "they" are pronouns.

You're welcome.

TTFN,
J

NO, they're not. Fog, mist, and such are tiny particles of LIQUID water
suspended in air.

Steam, which is water vapor, is invisible, transparent.

Get over it.

J

wrote:
NO, they're not. Fog, mist, and such are tiny particles of LIQUID water
suspended in air.

Steam, which is water vapor, is invisible, transparent.

Get over it.

J


Most people, and dictionaries, also call steam the visible water rising
from a pot of boiling water or other source.

--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

"dnoyeB" wrote in message

Most people, and dictionaries, also call steam the visible water rising
from a pot of boiling water or other source.

--
Thank you,

Most people and dictionaries will flunk the physics, chemistry, and
engineering tests about it also. You can join most people and dictionaries,
or you can be correct.

Edwin Pawlowski wrote:
wrote in message
oups.com...

Ok. I see I have created quite a war here. So why is it that My huge
boiler puts out no vapour, steam, "cloud", but my neighbors wimpy water
heater puts out a huge "cloud". Furthermore, lets say I like the
cloud, what can I do to cause the cloud when I install a new water
heater with b vent? What can be done to avoid the visible cloud with b
vent on a cold day? Thanks



Your huge heater is putting out the vapor, but it may be condensing inside
the chimney and just dropping down to the ground inside. Most chimneys have
a longer run than the high efficiency heaters that go out the side of the
house.

His boiler isn't condensing any moisture. The mass of water vapor
expelled isn't the issue. Temperature and absolute humidity are of
primary importance.

Richard Perry

"RP" wrote in message

His boiler isn't condensing any moisture. The mass of water vapor
expelled isn't the issue. Temperature and absolute humidity are of primary
importance.

Richard Perry

True in absolute terms but not comparative. He wants to know why one type of
heater makes more visible condensing vapor than the other. Assuming they
are burning about equal amounts of fuel, under equal weather conditions, why
does one seem to be more visible than the other type? You did not answer
that but I'm sure you will. .

Edwin Pawlowski wrote:
"RP" wrote in message

His boiler isn't condensing any moisture. The mass of water vapor
expelled isn't the issue. Temperature and absolute humidity are of primary
importance.

Richard Perry


True in absolute terms but not comparative. He wants to know why one type of
heater makes more visible condensing vapor than the other. Assuming they
are burning about equal amounts of fuel, under equal weather conditions, why
does one seem to be more visible than the other type? You did not answer
that but I'm sure you will. .

Suppose that one system cools the exhaust gases just to the point of
condensing moisture in the vent pipe but without actually condensing any.
This mixture will be at 100% RH. For the sake of argument alone let's
set the temperature of the outlet at 120ºF.
Now suppose the other system only cools the exhaust gas down to 150ºF at
the outlet. The RH of the exhausted gas in this system will thus be
less than 100%. We are assuming that both systems have burned gas at
exactly equal rates. Both will have produced the same quantity of water
vapor as byproduct, and the absolute humidity of the gasses in both vent
pipes will thus be the same (neglecting differences in density due to
temperature differences). The dewpoint will thus also be the same for
the outlet gasses of both.
The difference between these systems is that the first system's gasses
are already *at* dewpoint, while the second system's gasses must drop
30ºF before getting to dewpoint. IOW, if the gasses of these system
were to both drop 5º in temp in the first few inches of travel after
leaving their respective pipes, then the first will be condensing
moisture and the second will still have 25 more degrees to drop before
it could condense its moisture. If the gasses from the second system
travel sufficiently far to drop to 120ºF, where it could begin producing
fog, then it will instead have mixed with the ambient air causing its
absolute humidity to drop, which in turn reduces the dewpoint required
to produce fog. And if it mixes sufficiently with the ambient air as
its temp drops, then the required dewpoint may be pushed to well below
the ambient temp, thus preventing any possibility of producing fog.

The biggest fog producer of all systems will be the first system
described above. If you drop the outlet temp of the vent below the
saturated temp described for it, then condensation will be occurring in
the unit and/or vent pipe. The loss of moisture from the gasses will
cause the absolute humidity of the output to be lowered. It will still
be at dewpoint as it leaves, as in system1, but it will also be closer
in temp to the ambient temp and won't therefore cool as quickly. Thus
for maximum fog adjust the outlet temp such that the RH is at 100% but
with no condensation actually occurring within the system. Outdoor
ambient conditions also play a big part in fog formation from flue gasses.

Richard Perry

"RP" wrote in message


The biggest fog producer of all systems will be the first system described
above. If you drop the outlet temp of the vent below the saturated temp
described for it, then condensation will be occurring in the unit and/or
vent pipe. The loss of moisture from the gasses will cause the absolute
humidity of the output to be lowered. It will still be at dewpoint as it
leaves, as in system1, but it will also be closer in temp to the ambient
temp and won't therefore cool as quickly.

That is what I was trying to say, except in simpler terms. Your
descriptions is much more accurate and finally should settle the OP's
question.
thank you.
--
Ed
http://pages.cthome.net/edhome/

wrote:
Actually, adjective.

"You", "it", "they" are pronouns.

You're welcome.

TTFN,
J

By golly, you're correct, "your" is a possessive adjective, not a
possessive pronoun.

Bob

Edwin Pawlowski wrote:
"dnoyeB" wrote in message

Most people, and dictionaries, also call steam the visible water rising
from a pot of boiling water or other source.

--
Thank you,


Most people and dictionaries will flunk the physics, chemistry, and
engineering tests about it also. You can join most people and dictionaries,
or you can be correct.



Unless physicists talk in another language, the dictionary by definition
is correct.

--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16

"dnoyeB" wrote in message


Unless physicists talk in another language, the dictionary by definition
is correct.

--
Thank you,

They do, thank you.

http://www.answers.com/topic/steam
In physical chemistry and in engineering, steam refers to vaporized water.
It is a pure, invisible gas (for mist see below), which at standard
atmospheric pressure has a temperature of around 100 degrees Celsius, and
occupies about 1,600 times the volume of liquid water (steam can of course
be much hotter than the boiling point of water; such steam is usually called
superheated steam).

Ah, Ed. I'm disapointed. Of all the people who would know the diff between
quotes and parenthases. But at least you didn't say "quote unquote" which
many folks use incorrectly. A typical usage would be that the person said,
quote unquote, you're fat. Now, in this usage, there is no quoted text.

Anyhow, (paranthetically), I think you're right about stem being invisible.
And you can quote me as agreeing with you.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"Edwin Pawlowski" wrote in message
m...

wrote in message
....
Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?


I'm glad you put "steam" in parenthesis, because, as you already surmise it
is not steam. To be picky, steam is invisible. It is a vapor and cannot be
seen at all. What you are seeing is condensation that is now visible in the
cold air.

When fuel is burned, there are products of combustion that are given of into
the air. The type of products depends on the fuel. Could be ash, soot,
smoke (that contains many compounds) and water. Propane and natural gas
both contains some water. the water, of course will not burn but will be
vaporized and later condensed (made visible) and that is what you are
seeing. For the products of combustion to pass up that big cold clay
chimney, some of the condensation will drop back down and dry up. some will
exit and not be seen. High efficiency units are sending the water vapor out
a shorter length of PVC and you see more of it.

Uh, no. The ninety percenter has a drain, and much of the water vapor is
condensed and run down the drain. So, and 80 percenter dumps much more water
vapor up the stack.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"Edwin Pawlowski" wrote in message
...

"RP" wrote in message

Your last point BTW is completely incorrect; the high efficiency unit is
sending *less* water vapor out. Even so, some of what it does send out
condenses before it gets far from the outlet, again, because its dew
point is much closer to its saturated temp than in the low efficiency unit
output.

Would they not both send out the same amount of vapor per ccf of gas burned?
Your explanation is more detailed than mine though. Thanks.

ah, but potassium iodate tablets will prevent absorption. Either that, or
massive doeses of dihydrogen monoxide, orally, will prevent absorption. I'm
never sure which.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

wrote in message
...
On 25 Jan 2006 18:09:26 -0800, wrote:

Greetings. I live outside of detroit, mi. I notice that my neighbors
natural gas water heaters that are vented with b-vent seem to give a
fair sized cloud of "steam" if you will, on a cold morning. My 220,000
btu boiler that is venting into a clay flue 8x8 chimney does not cause
any steam to be visible at all. It should be noted that my natural gas
water heater vents into the same chimney. People with the 90+%
furnaces have a huge cloud of steam coming from their furnace vents.
My question is: what causes some people to have steam and others not?

What you see is not actually steam, but is a release, due to a bad
connection, of leakage from the nuclear heater that is used in some
new installations. Do not allow your children to go outside when it
is visible, or for four hours afterwards.


Remove NOPSAM to email me. Please let
me know if you have posted also.

Dear Bob, you're right, in your assertion.

What about his welcome?

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
..

"RobertM" wrote in message
...

Your welcome.

Richard Perry


Well, no. To be perfectly correct, it would be "you're welcome",
contraction for "you are". "Your" is a possessive pronoun.

Bob