On Nov 26, 5:53*pm, Vic Smith wrote:
On Mon, 26 Nov 2012 05:29:20 -0800 (PST), "
wrote:
*Chimneys cool off fast in winter.
That's why there are few unlined chimneys left.
Talking about NG only. *Haven't had coal or oil in decades.
Condensation talk is to sell liners to those who don't have them,
or to now sell a hi-efficiency water heater with a dedicated vent.
You're obviously an idiot. *Condensation is a real issue.
So is the hole in the ozone layer. *And global warming.
As expected from you, you can't keep up. *Water heater flues flow into
cold chimneys all winter. *Sunny days can keep the furnace off for
hours. *Chimney is cold. *Water heater lights up.
If it's that sunny and mild in winter so that the furnace stays
off for hours, then the chimney is also not that
cold, hence any condensation will be minimal.
Now look at the real problem. The days and nights
when it's 20 or 10F. You have a chimney that was sized
for a big old honking furnace and water heater.
Now all that goes up it is the water heater, once in
a while. Result: Condensation. In fact, all the water
is condensing inside the chimney. If it's a masonry
chimney, the acid in that water will destroy it over
time
Happens all the time, and has for ages.
Deny that all you want.
Most chimney flues are lined. *Mine is lined with SS.
Most flues are not lined. The orphaned water heater
problem is specific to masonry chimneys. The solution
is to line it.
Also has a condensate drain.
That should be addressed when replacing/upgrading a furnace.
Had mine installed 17 years ago.
What, your condensate drain?
I call that "home maintenance." *Wasn't required by code.
You wouldn't know what is or isn't required by code.
You think chimney sizing isn't covered by code. It
sure as hell is here, in NJ and other states that follow
the national fuel gas code.
Chimneys are not collapsing all across the country from acid corrosion
or freeze/thaw spalling. *A furnace and WH are independent actors.
Always have been.
According to you and your flapping gums. Here are just a
few of the many credible sources that say you're wrong:
This one is from govt, so being a lib that love govt, you
should like it:
http://mn.gov/commerce/energy/images...terHeaters.pdf
Beware the “Orphaned”
Water Heater
In the past, older furnaces, boilers, and water heaters would
frequently
share the same chimney to exhaust flue gasses. Today’s high-efficiency
boilers and furnaces bypass the old chimney and are vented through
separate PVC piping.
If the old “atmospherically-vented” gas water heater is not replaced
with a
high-efficiency “direct-vented” unit when the furnace/boiler is
upgraded,
the water heater venting can become “orphaned” and lead to a
potentially
dangerous carbon monoxide hazard. Under some circumstances, the
old chimney may not adequately exhaust the water heater’s combustion
products, resulting in spillage back into the home.
Here's one from a home inspection website:
http://www.totalhomeinspection.com/hints_chimneys.shtml
Chimneys - When a Flue is Too Big
Most older homes, especially in the Northeast, use masonry chimneys to
vent their combustion appliances. During the past ten years, many old
furnaces and boilers have been gradually replaced with higher-
efficiency models that use PVC sidewall vents. When an older furnace
is disconnected from a masonry chimney, it may leave behind a so-
called "orphaned" water heater, attached to a flue that is now
oversized.
However, when it comes to sizing a flue, bigger isn't always better.
Oversized flues can contribute to at least three problems: poor draft,
chimney corrosion, and freeze/thaw damage to the chimney.
Here's one from Cornell. You libs like govt and academia,
right?
http://www.human.cornell.edu/dea/out...ge-8-2012..pdf
What is an orphaned water heater and what can be done to avoid
problems
associated with an orphaned water heater?
A: “Orphaned” water heater is a term used to describe a storage tank
style residential
domestic hot water heater that gets left alone as the only combustion
appliance vented to
a chimney after a furnace or boiler is removed. This usually happens
when an older
furnace or boiler is replaced by a new and much more efficient model.
These newer
heating systems capture more heat from the combustion process than
older systems. The
result is that the temperature of the flue gasses in newer systems is
much lower compared
to older, less efficient systems. Since the temperatures of the flue
gasses are cooler, it
makes it possible to vent them directly to the outdoors via a plastic
pipe. A fan, built into
the furnace or boiler is used to blow combustion gasses through the
vent pipe directly to
the outdoors.
5 Revised 2012-07
To understand how orphaned water heaters can create problems, it is
useful to first think
about how a chimney works. A chimney is basically a hollow vertical
column with an
opening at the top that is exposed to the outdoors. The chimney also
has an opening near
the bottom that is typically accessed through the basement wall of the
house. Exhaust
gasses from combustion appliances are directed to this hole near the
bottom of the
chimney via a metal duct called a flue. Combustion appliances that are
relatively
inefficient loose lots of heat to the exhaust gasses. It is the heat
contained within the
combustion gasses that create the natural forces-hot air rises- that
draws exhaust gasses
up and out of the chimney. If the combustion gasses being directed to
the chimney by a
combustion appliance are not hot enough, or do not create a sufficient
volume of hot air
to initiate the draft of the gasses up the chimney, then the
combustion gasses spill back
into the home. Combustion gasses contain many harmful chemicals,
including lethal
carbon monoxide, so spillage of those gasses into a home can be very
dangerous. And
exhaust gasses from natural gas or liquefied petroleum gas (propane)
appliances are
virtually odorless and invisible. This means if spillage is occurring
regularly in homes
with orphaned gas water heaters, occupants are usually not aware of
the problem until
they begin experiencing negative health effects.
Spillage is not the only problem that can occur. Since combustion
gasses contain
significant amounts of water vapor, there is now a risk of
condensation forming within
the chimney. For example, on a cold winter day, the walls of the
chimney may be cold
enough so that the water vapor contained within the combustion gasses
will condense.
When this occurs over time, the acidic condensate can destroy the
chimney.
As to chimneys not collapsing, here's some photos of
some that have substantial condensation damage:
http://activerain.com/blogsview/3392...ce-on-chimneys
http://www.brothers-masonry-restorat...otogalary.html
http://localism.com/blog/ny/posts/30...E-OF-THE-MONTH
There are codes that specify the size of a chimney for the
particular appliance. *You can't just vent any size appliance
into any size chimney. * There is a max size allowed.
It's like saying the issue of putting a 20 amp breaker
on 14 gauge wire is just to sell breakers.
No sense at all there. *Chimneys don't work by electricity.
Codes were/are written for furnace/WH running, furnace only, WH only.
Remove furnace or WH from the stack, and the other works just fine.
Yeah, there is no sense there, because you're flat out
wrong. The national fuel gas codes specify permitted
chimney sizing relative to the size of the appliances
connected.
An old house with chimney venting installed before codes, or adequate
codes, should face the local inspector.
Oh, really? Adequate codes according to whom, you?
Around here, NJ, you need a permit and inspection to
replace a furnace period. I would think that would be the
case in many other jurisdictions as well.
Probable worst case is you have to install a liner, *Because of draft,
not condensation.
Well, you're starting to learn. But why would that be?
You just told us two paragraphs ago that chimney size
doesn't matter. Now, suddenly it does.
CO is the big issue with an over-sized chimney.
You're a cracker-barrel type guy, and a good target for salesmen.
That's okay. *Takes ll kinds.
And you're an imbecile. Now go and google "orphaned
water heater" You might learn something instead of
continuing to make an ass of yourself.