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Home > Archive > Alternative Power sources > September 2007 > Hydrogen as heat storage?
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| Author |
Hydrogen as heat storage?
|
|
| dances_with_barkadas@yahoo.com 2007-09-03, 11:12 am |
| reference:
http://www.engineeringtoolbox.com/hydrogen-d_976.html
Hydrogen has more than triple the heat-storage-capacity of water.
Safe storage of H2 in cylinders is a standard technology. But I don't
see it being used for heat storage.
Why not?
| |
|
|
<dances_with_barkadas@yahoo.com> wrote in message
news:1188679541.397915.273940@22g2000hsm.googlegroups.com...
> reference:
>
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
>
> Hydrogen has more than triple the heat-storage-capacity of water.
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
>
Something to do with the price of hydrogen being more than triple the price
of water would be my guess. But it is used for cooling in large generators.
| |
| Anthony Matonak 2007-09-03, 11:12 am |
| dances_with_barkadas@yahoo.com wrote:
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
> Hydrogen has more than triple the heat-storage-capacity of water.
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
Perhaps it has to do the rather inconvenient temperature that liquid
hydrogen requires, it's propensity to leak through near everything,
the way it changes materials, it's cost, flammability or explosive
nature.
That said, hydrogen and helium seem to be popular for heat engines.
Anthony
| |
| dances_with_barkadas@yahoo.com 2007-09-03, 11:12 am |
|
> the rather inconvenient temperature that liquid
> hydrogen requires, it's propensity to leak through near everything,
> the way it changes materials, it's cost, flammability or explosive
> nature.
As the reference indicated, I'm talking about gasous Hydrogen. They
sell the cylinders in the Yellow Pages, it can't be rocket science.
Liquid H2 is rocket science.
I can't find any recent H2-inside-cylinder caused fires or explosions
in googling. Can you name one?
We live in houses which have natural gas piped into them; we live in
houses which keep large tanks of propane beside them; we drive
vehicles carrying double-digit gallons of liquid gasoline. Is
hydrogen a higher risk?
| |
| Morris Dovey 2007-09-03, 11:12 am |
| dances_with_barkadas@yahoo.com wrote:
| Is hydrogen a higher risk?
Yes.
--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/
| |
|
| dances_with_barkadas@yahoo.com wrote:
> reference:
>
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
>
> Hydrogen has more than triple the heat-storage-capacity of water.
That would be in in weight, not volume.
Now calculate out out how many cubic feet of hydrogen it takes to
weigh the same as 1/3 cubic foot of water. Last time I checked water was
a lot heavier than hydrogen.
Jeff
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
>
| |
| Anthony Matonak 2007-09-03, 11:12 am |
| dances_with_barkadas@yahoo.com wrote:
>
> As the reference indicated, I'm talking about gasous Hydrogen. They
> sell the cylinders in the Yellow Pages, it can't be rocket science.
> Liquid H2 is rocket science.
You're suggesting storing heat in hydrogen gas as better than
storing it in liquid water? Hydrogen gas is pretty light. It
seems to me that it'll take a heck of a lot of very light gas
to equal the heat capacity of a few gallons of water.
Why not put some numbers to it? Say you're looking to store
heat for keeping the house warm, around 77F, 25C, 298K.
http://www.engineeringtoolbox.com/w...ties-d_162.html
at 25C specific heat is 4.181 kJ/kgK and density 997.1 kg/m^3.
This gives us heat storage of 4169 kJ/m^3K.
http://www.engineeringtoolbox.com/hydrogen-d_976.html
http://www.engineeringtoolbox.com/g...sity-d_158.html
at 298K specific heat is 14.3 kJ/kgK and density is 0.0899 kg/m^3.
Roughly speaking (since I don't want to bother with ideal gas laws
and whatever pressure those S-Mart hydrogen tanks use) this gives
us heat storage of 1.29 kJ/m^3K.
Which would you rather use? Very cheap water at 4169 kJ/m^3K or very
expensive hydrogen at 1.29 kJ/m^3K? Let me tell you a secret, one of
them stores 3200 times more than the other.
Anthony
| |
| hhc314@yahoo.com 2007-09-03, 11:12 am |
| On Sep 1, 7:54 pm, dances_with_barka...@yahoo.com wrote:
> I can't find any recent H2-inside-cylinder caused fires or explosions
> in googling. Can you name one?
It is not when the H2 is stored in a sealed cylinder that the risk
exist, it is when the H2 leaks out and mixes with atmospheric O2.
Google deeper and you'll find that hydrogen explosions are a major
hazard in facilities that employ it, like manufacturing facilities and
research labs. I recall two structures here in Boston that were
destroyed by H2 explosions during the past 10 years.
> We live in houses which have natural gas piped into them; we live in
> houses which keep large tanks of propane beside them; we drive
> vehicles carrying double-digit gallons of liquid gasoline. Is
> hydrogen a higher risk?
Yes, very definitely. There is no comparison. That's precisely why
facilities that employ H2 are generally equipped with sensitive
hydrogen detection alarms and automatic ventilation facilities. I
fact, H2 emission is generally a safety consideration requiring
positive forced ventillation where storage batteries are being
recharged, usually required by law here in the US.
Even in cars, I've seen 3 instance of car batteries exploding as a
result of the emitted hydrogen. My son owned one of these, and I
believe I still have photos available on-line somewhere, and if you
would like to see the resulting damage, if I can locate them I'll be
happy to mail your a photo.
Harry C.
| |
| Eeyore 2007-09-03, 11:12 am |
|
dances_with_barkadas@yahoo.com wrote:
> reference:
>
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
> Hydrogen has more than triple the heat-storage-capacity of water.
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
Hydrogen has a very small molecule so diffuses through just about everything.
In other words, it leaks out. It's also explosive.
Waxes with melting points similar to your desired storage temperature are
excellent at storing heat as much of it is stored as 'latent heat' whch is a
very efficient way of storing heat.
Graham
| |
| BioFreak 2007-09-03, 11:12 am |
| On Sat, 01 Sep 2007 13:45:41 -0700,
dances_with_barkadas@yahoo.com wrote:
> reference:
>
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
>
> Hydrogen has more than triple the heat-storage-capacity of water.
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
The heck is "heat storage". Go do yourself. If you need
to give, go give it to him:
http://www.shabnameh.org/images/ehsasBJm.jpg
--
"rafti sare manbar!"
- Jalal Ale-Ahmad
| |
| David Williams 2007-09-03, 11:12 am |
| -> Hydrogen has a very small molecule so diffuses through just about everythin
-> In other words, it leaks out. It's also explosive.
Actually, a molecule of hydrogen is about the same size as a molecule
of any other diatomic gas, such as oxygen. However, at any given
temperature, hydrogen molecules move faster than more massive
molecules. Their average kinetic energy is the same, so the less
massive the molecule, the faster it moves. This means that hydrogen
molecules move more quickly through any tiny holes in the container, so
it leaks out faster, but it will not leak out of any container from
which oxygen, etc., cannot leak. If any holes are too small for oxygen
molecules to pass, they are also too small for hydrogen.
dow
| |
| CWatters 2007-09-03, 11:12 am |
|
<dances_with_barkadas@yahoo.com> wrote in message
news:1188690857.950580.45800@k79g2000hse.googlegroups.com...
>
>
>
> As the reference indicated, I'm talking about gasous Hydrogen. They
> sell the cylinders in the Yellow Pages, it can't be rocket science.
> Liquid H2 is rocket science.
House builders don't really like installing mains pressure unvented hot
water storage cylinders for safety reasons - or rather the extra paperwork
required.
| |
| daestrom 2007-09-03, 11:12 am |
|
"CWatters" <colin.watters@turnersNOSPAMoak.plus.com> wrote in message
news:13dme8senu2o74c@corp.supernews.com...
>
> <dances_with_barkadas@yahoo.com> wrote in message
> news:1188690857.950580.45800@k79g2000hse.googlegroups.com...
>
>
> House builders don't really like installing mains pressure unvented hot
> water storage cylinders for safety reasons - or rather the extra paperwork
> required.
>
Might you be talking about the UK?? In the States, most all hot water
heates are piped directly to 'mains pressure'. A combination
temperature/pressure relief valve provides more than enough safety in just
about all cases. The only hot-water cylinder 'explosions' I've ever heard
of in modern times have been propane gas leaks and pilot lights.
daestrom
>
| |
| hhc314@yahoo.com 2007-09-03, 5:25 pm |
| On Sep 3, 10:23 am, "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com>
wrote:
> "CWatters" <colin.watt...@turnersNOSPAMoak.plus.com> wrote in message
>
> news:13dme8senu2o74c@corp.supernews.com...
>
>
>
>
>
>
>
>
>
>
>
> Might you be talking about the UK?? In the States, most all hot water
> heates are piped directly to 'mains pressure'. A combination
> temperature/pressure relief valve provides more than enough safety in just
> about all cases. The only hot-water cylinder 'explosions' I've ever heard
> of in modern times have been propane gas leaks and pilot lights.
>
> daestrom
>
>
>
> - Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
Agreed, but just one nit. Building codes in the US require the hot
water tank to have a pressure capacity at least equal to the mains
pressure, and be equipped with both an approved temperature/pressurue
release valve with a pressure setting less than the burst presure
rating of the tank (which is required by law to be stamped on the
tank's label).
Also, they are required to be equipped with a pilot light sensor
(generally using a thermocouple) which turns off BOTH and main burner
valve and the pilot light gas feed if the pilot light were to be
extinguished for any reason. The same is true for gas operated home
furnaces.
Some states is the US also require a gas water heater to be equipped
with a "vacuum breaker" valve on the water feed line, which allow air
to enter the tank if a negative pressure were to develop in the water
supply line. This can happen if a fire developes in the neighborhood,
and the fire department is heavily pumping from nearby fire hydrants.
In Europe, things are quite different. There the tankless "instant hot
water" type systems are much more common. I have no idea what
regulations apply to them, but in fact believe that in a failure mode,
they could be quite dangerous.
Here in the US, most hot water tanks fail gradually, by leaking their
contents all over the floor. This generally happend withing a year or
two of the tanks warranty expiration. :-)
I've never heard of a catastrophic burst of a hot water heater in this
country, but it does become an emergency when the tank takes of a
serious leak and begins flooding your home or basement, plus you have
no hot water. The water leakage can be resolved by turning off the
mains flow to the heater, but you still have to take a cold shower
until you obtain a replacement. Bummer! :-)
Harry C.
p.s., Plus, it always happens on a weekend or a holiday!
| |
| daestrom 2007-09-04, 5:25 pm |
|
<hhc314@yahoo.com> wrote in message
news:1188851982.068344.196130@d55g2000hsg.googlegroups.com...
> On Sep 3, 10:23 am, "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com>
> wrote:
>
> Agreed, but just one nit. Building codes in the US require the hot
> water tank to have a pressure capacity at least equal to the mains
> pressure, and be equipped with both an approved temperature/pressurue
> release valve with a pressure setting less than the burst presure
> rating of the tank (which is required by law to be stamped on the
> tank's label).
>
> Also, they are required to be equipped with a pilot light sensor
> (generally using a thermocouple) which turns off BOTH and main burner
> valve and the pilot light gas feed if the pilot light were to be
> extinguished for any reason. The same is true for gas operated home
> furnaces.
>
Nevertheless, gas hotwater heaters have 'exploded' causing fires. I think
it's not so much the tank bursting from overpressure but a question of
combustible fumes finding the lit pilot light. Probably a misnomer to blame
the hotwater heater, it was only the ignition source. (the 'common
knowledge' not to store flammables in a basement near the heater is
sometimes not so common).
> Some states is the US also require a gas water heater to be equipped
> with a "vacuum breaker" valve on the water feed line, which allow air
> to enter the tank if a negative pressure were to develop in the water
> supply line. This can happen if a fire developes in the neighborhood,
> and the fire department is heavily pumping from nearby fire hydrants.
>
> In Europe, things are quite different. There the tankless "instant hot
> water" type systems are much more common. I have no idea what
> regulations apply to them, but in fact believe that in a failure mode,
> they could be quite dangerous.
>
> Here in the US, most hot water tanks fail gradually, by leaking their
> contents all over the floor. This generally happend withing a year or
> two of the tanks warranty expiration. :-)
Yep, been there. Can be extended if you take the time to check the zinc
anode, but most folks don't even know where to look :-)
<snip>
>
> p.s., Plus, it always happens on a weekend or a holiday!
>
Aint that the truth!!
daestrom
| |
|
|
<hhc314@yahoo.com> wrote in message
news:1188851982.068344.196130@d55g2000hsg.googlegroups.com...
In the UK they have to be fitted by certified people G3 under building regs.
They also need an annual service if there is burner incorporated or not.
The UK has the highest standard of unvented cylinder protection of any
country and still wants only certified trained people to touch them.
[color=darkred]
I know of one that exploded because the pressure vessel failed and the
pressure relief valve leaked. A smart DIYer stopped the leak by capping the
pipe with a compression cap. Kaboom!!!!
http://waterheaterblast.com
[color=darkred]
> Some states is the US also require a gas water heater to be equipped
> with a "vacuum breaker" valve on the water feed line, which allow air
> to enter the tank if a negative pressure were to develop in the water
> supply line. This can happen if a fire developes in the neighborhood,
> and the fire department is heavily pumping from nearby fire hydrants.
What is wrong with a check valve?
> In Europe, things are quite different.
> There the tankless "instant hot
> water" type systems are much more
> common.
Combis with most being small wall mounted boxes - brilliant for apartments
saving much space. Some are floor mounted Combines the central heating and
instant hot water. Some of them can belt out the flowrates, especially the
floor mounted units. The cheaper wall mounted units are so cheap they are
virtually throw way items. All parts are replaceable, but the cost sometimes
is more than a new unit complete with a guarantee.
> I have no idea what
> regulations apply to them,
> but in fact believe that in a failure mode,
> they could be quite dangerous.
They are full of high limit devices to cut out the burner and a pressure
relief valve.
| |
|
| "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:46ddbdcc$0$4071$4c368faf@roadrunner.com...
>
>
> Yep, been there. Can be extended if you take the time to check the zinc
> anode, but most folks don't even know where to look :-)
In the UK unvented cylinders "tend" to be stainless steel. Look at this all
in one stainless steel boiler and tank-in-tank design - a tank inside a
thermal store:
http://www.acv-uk.com/heatmaster35.htm
Manual:
http://www.acv-uk.com/pdf/HeatMaster%2035-85TC.pdf
The manual explains the operation very well with nice diagrams too. It
always condenses promoting high efficiency.
Here is a Dutch copper design - still very good.
http://www.atmos.uk.com/product_gro...on=000200130001
These units do CH and DHW and are "very" efficient.
| |
|
|
<hhc314@yahoo.com> wrote in message
news:1188851982.068344.196130@d55g2000hsg.googlegroups.com...
> Also, they are required to be equipped with a pilot light sensor
> (generally using a thermocouple) which turns off BOTH and main burner
> valve and the pilot light gas feed if the pilot light were to be
> extinguished for any reason. The same is true for gas operated home
> furnaces.
In Europe pilotless ignition is pretty well the norm. Pilot only comes in
when the burner is called.
> Some states is the US also require a gas water heater to be equipped
> with a "vacuum breaker" valve on the water feed line, which allow air
> to enter the tank if a negative pressure were to develop in the water
> supply line. This can happen if a fire developes in the neighborhood,
> and the fire department is heavily pumping from nearby fire hydrants.
An anti-vacuum valve can be anywhere on the tank. Why on the incoming cold
mains pipe?
| |
| Don Young 2007-09-05, 9:25 pm |
|
"News" <Nospam@here.com> wrote in message
news:46de6f23$0$47101$892e7fe2@authen.yellow.readfreenews.net...
>
> <hhc314@yahoo.com> wrote in message
> news:1188851982.068344.196130@d55g2000hsg.googlegroups.com...
>
>
> In Europe pilotless ignition is pretty well the norm. Pilot only comes in
> when the burner is called.
>
>
> An anti-vacuum valve can be anywhere on the tank. Why on the incoming cold
> mains pipe?
I would think it's to prevent siphoning of water from any part of the
househould plumbing back into the municipal supply lines.
Don Young
| |
| David Williams 2007-09-06, 3:25 am |
| -> >> Some states is the US also require a gas water heater to be equipped
-> >> with a "vacuum breaker" valve on the water feed line, which allow air
-> >> to enter the tank if a negative pressure were to develop in the water
-> >> supply line. This can happen if a fire developes in the neighborhood,
-> >> and the fire department is heavily pumping from nearby fire hydrants.
-> >
-> > An anti-vacuum valve can be anywhere on the tank. Why on the incoming cold
-> > mains pipe?
-> I would think it's to prevent siphoning of water from any part of the
-> househould plumbing back into the municipal supply lines.
-> Don Young
We wouldn't want our water to be sucked out and used for fighting
someone else's fire, would we?
dow
| |
|
|
"Don Young" <notme@nonesuch.com> wrote in message
news:13dunj3t6ril114@corp.supernews.com...
>
> "News" <Nospam@here.com> wrote in message
> news:46de6f23$0$47101$892e7fe2@authen.yellow.readfreenews.net...
> I would think it's to prevent siphoning of water from any part of the
> househould plumbing back into the municipal supply lines.
>
> Don Young
The correct way is a check valve on the incoming supply and an anti-siphon
valve at the top of the tank. If the check valve passed and a fire engine
sucked the water out of the house, the tank could implode. The anti-vacuum
valve prevents imploding.
I think this "vacuum breaker", creates an air gap so prevents the water
being sucked out of the tank if the check valve fails.
>
>
| |
| Don Young 2007-09-06, 9:25 pm |
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1189051525.912.1189047901@bayman.org...
>-> >> Some states is the US also require a gas water heater to be equipped
> -> >> with a "vacuum breaker" valve on the water feed line, which allow
> air
> -> >> to enter the tank if a negative pressure were to develop in the
> water
> -> >> supply line. This can happen if a fire developes in the
> neighborhood,
> -> >> and the fire department is heavily pumping from nearby fire
> hydrants.
> -> >
> -> > An anti-vacuum valve can be anywhere on the tank. Why on the incoming
> cold
> -> > mains pipe?
> -> I would think it's to prevent siphoning of water from any part of the
> -> househould plumbing back into the municipal supply lines.
>
> -> Don Young
>
> We wouldn't want our water to be sucked out and used for fighting
> someone else's fire, would we?
>
> dow
I think the concern is possible contamination of the municipal water supply
lines from anything introduced into the household plumbing. There are quite
a few cross connection, air gap, check valve, vacuum breaker, and
anti-siphon regulations to help prevent this. I make no judgements as to
whether said regulations are necessary or worthwhile.
Don Young
| |
| David Williams 2007-09-07, 9:25 am |
| -> > We wouldn't want our water to be sucked out and used for fighting
-> > someone else's fire, would we?
-> >
-> > dow
-> I think the concern is possible contamination of the municipal water supply
-> lines from anything introduced into the household plumbing. There are quite
-> a few cross connection, air gap, check valve, vacuum breaker, and
-> anti-siphon regulations to help prevent this. I make no judgements as to
-> whether said regulations are necessary or worthwhile.
-> Don Young
Sounds to me like something a lawyer thought up.
dow
| |
|
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1189175734.912.1189134294@bayman.org...
>-> > We wouldn't want our water to be sucked out and used for fighting
> -> > someone else's fire, would we?
> -> >
> -> > dow
> -> I think the concern is possible contamination of the municipal water
> supply
> -> lines from anything introduced into the household plumbing. There are
> quite
> -> a few cross connection, air gap, check valve, vacuum breaker, and
> -> anti-siphon regulations to help prevent this. I make no judgements as
> to
> -> whether said regulations are necessary or worthwhile.
>
> -> Don Young
>
> Sounds to me like something a lawyer thought up.
Legislators make laws, lawyers simply twist them to their clients
advantage.
>
> dow
| |
| Arnold Walker 2007-09-07, 5:25 pm |
|
<dances_with_barkadas@yahoo.com> wrote in message
news:1188679541.397915.273940@22g2000hsm.googlegroups.com...
> reference:
>
> http://www.engineeringtoolbox.com/hydrogen-d_976.html
>
>
> Hydrogen has more than triple the heat-storage-capacity of water.
> Safe storage of H2 in cylinders is a standard technology. But I don't
> see it being used for heat storage.
>
> Why not?
>
Because helium and nitrogen does better with far fewer explosion when it
leaks.
----== Posted via droptable.com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.droptable.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
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| |
| David Williams 2007-09-07, 5:25 pm |
| -> Legislators make laws, lawyers simply twist them to their clients
-> advantage.
A lot of legislators are lawyers too, and go back to being lawyers when
they lose elections.
dow
| |
|
|
"David XXXXXXXX" <david.XXXXXXXX@bayman.org> wrote in message
news:1189197083.912.1189184674@bayman.org...
>-> Legislators make laws, lawyers simply twist them to their clients
> -> advantage.
>
> A lot of legislators are lawyers too, and go back to being lawyers when
> they lose elections.
>
> dow
Oh yes; I am friends with some of the legislators in various states, and
my daughter in law's brother is one here.
Once a lawyer, always a lawyer..... ;-)
| |
| daestrom 2007-09-08, 5:25 pm |
|
"News" <Nospam@here.com> wrote in message
news:46ddcf3f$0$47143$892e7fe2@authen.yellow.readfreenews.net...
> "daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
> news:46ddbdcc$0$4071$4c368faf@roadrunner.com...
>
> In the UK unvented cylinders "tend" to be stainless steel. Look at this
> all in one stainless steel boiler and tank-in-tank design - a tank inside
> a thermal store:
>
> http://www.acv-uk.com/heatmaster35.htm
> Manual:
> http://www.acv-uk.com/pdf/HeatMaster%2035-85TC.pdf
> The manual explains the operation very well with nice diagrams too. It
> always condenses promoting high efficiency.
>
> Here is a Dutch copper design - still very good.
> http://www.atmos.uk.com/product_gro...on=000200130001
>
> These units do CH and DHW and are "very" efficient.
>
Yes, but I have to be a bit leery when the first one lists hot-water heating
efficiency as '105%' :-)
Apparently they are calculating based on the lower-heating value of the
fuel. They can extract more than 100% of that heating value by the
condensing of water out of the exhaust gasses. So I suppose for comparison
with non-condensing units (which also use the LLV of the fuel), its best to
stick with the same values. :-)
Nice units, wish we had condensing hot-water heaters here in the states.
I've got forced-hot-air heating for the home and separate hot-water heater.
But it isn't anywhere near 90% of LLV, much less >100%. :-(
daestrom
| |
|
|
"daestrom" <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote in message
news:46e30b6d$1$18959$4c368faf@roadrunner.com...
>
> "News" <Nospam@here.com> wrote in message
> news:46ddcf3f$0$47143$892e7fe2@authen.yellow.readfreenews.net...
>
> Yes, but I have to be a bit leery when the first one lists hot-water
> heating efficiency as '105%' :-)
>
> Apparently they are calculating based on the lower-heating value of the
> fuel. They can extract more than 100% of that heating value by the
> condensing of water out of the exhaust gasses. So I suppose for
> comparison with non-condensing units (which also use the LLV of the fuel),
> its best to stick with the same values. :-)
100% was based on "sensible" heat. When latent heat is taken into acount the
scale goes over 100%, up to around 109% maximum.
> Nice units, wish we had condensing
> hot-water heaters here in the states.
Energy is too cheap over there. Necessity is the mother of invention.
> I've got forced-hot-air heating for
> the home and separate hot-water
> heater. But it isn't anywhere near
> 90% of LLV, much less >100%. :-(
I believe the ACV units are available in the USA. These are the agents:
http://www.triangletube.com/Condens...igeOverview.htm
A quick look and they sell the wall mounted Prestige at least. This also
comes as a stored water (integral DHW cylinder) on-demand water heater, that
also does CH. So it could heat a forced air unit with a copper coil. Most
forced air units are adaptable and can have copper coils fitted. Then one
condensing burner doing CH and DHW. The HeatMaster can also heat a copper
coil too. Just a thought.
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| dances_with_barkadas@yahoo.com 2007-09-13, 1:25 pm |
| > Nice units, wish we had condensing hot-water heaters here in the
> states.
ok, fine; just be careful of what else might get condensed. Say for
example, depending upon your fuel, amounts of sulphuric acid.
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