A stem may be invisible, especially when it is encased in something like a
gate valve, but steam is not always invisible.

"Stormin Mormon" wrote in message
. ..
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.

Edwin Pawlowski wrote:
"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).



If this were a physics forum I wouldn't disagree.


--
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