Trying to get ahead of the curve here. Heating season is approaching
and my boiler is old. I doubt I will replace it until absolutely
necessary, but when it happens, I will need to decide what kind to
get. House is about 2400 sq ft and climate is fairly severe
(Chicago). Hot water heat, natural gas fired. Have separate water
heater for domestic uses. The boiler I have now is a Peerless unit
from the 1980s.

I see you can get units that are 95% efficient, with sealed combustion
chambers and stainless steel heat exchangers. All of those sound like
good ideas, but how are they in practice? Do your fuel bills drop?
Do they give trouble? Do they last? Are they worth the extra $$? --
H

On Sep 17, 4:20*pm, Heathcliff wrote:
Trying to get ahead of the curve here. *Heating season is approaching
and my boiler is old. *I doubt I will replace it until absolutely
necessary, but when it happens, I will need to decide what kind to
get. *House is about 2400 sq ft and climate is fairly severe
(Chicago). *Hot water heat, natural gas fired. *Have separate water
heater for domestic uses. The boiler I have now is a Peerless unit
from the 1980s.

Need some more info to give you a complete answer.

Clearly you have hot water heat, but what kind? The issue is that
condensing boilers maximize their efficiency when their return water
temp is below 130 F. If you have a baseboard system, you will never
see temps that low, and, even with radiators, you probably won't be
able to heat your house in cold weather with water temps like that.
The question is "How much efficiency do you lose at say, 150F for a
water temp?" If it is a percent or two, no big deal, but any more
than that really starts to affect the payback. Given that these
boilers aren't typically expected to last more than 15 years (give or
take), and they cost about twice as much, it is hard to make the
numbers work unless you have radiant floor heat, which operates at
lower temps.

You also have to be careful when sizing and setting the temp for
domestic hot water, since setting the temp sky high will give you
faster recovery, but affects the efficiency also.

JK



I see you can get units that are 95% efficient, with sealed combustion
chambers and stainless steel heat exchangers. *All of those sound like
good ideas, but how are they in practice? *Do your fuel bills drop?
Do they give trouble? *Do they last? *Are they worth the extra $$? *--
H

I did a little more research on the topic, and here is a pretty good
article on it. Looks like the answer is that a "condensing" boiler
operating at high temps is only about 88% efficient, or about 4-6%
more efficient than reliable, long lasting, cast iron.

JK

Hardly going to pay for all the extra doodads that are sure
to break down regularly.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Big_Jake" wrote in message
...
I did a little more research on the topic, and here is a
pretty good
article on it. Looks like the answer is that a "condensing"
boiler
operating at high temps is only about 88% efficient, or
about 4-6%
more efficient than reliable, long lasting, cast iron.

JK

On Sep 17, 9:56*pm, Big_Jake wrote:
I did a little more research on the topic, and here is a pretty good
article on it. *Looks like the answer is that a "condensing" boiler
operating at high temps is only about 88% efficient, or about 4-6%
more efficient than reliable, long lasting, cast iron.

JK

Thanks for the info - what is the URL for the article?

I have cast iron radiators and big old iron pipes serving them - I
think the system was originally a gravity circulator. When the
weather gets good and cold and the unit runs for a while, the
thermometer on the boiler gets up to maybe 180 or 185; I assume that
is the temperature inside the unit, not the return temperature. I
don't know what the return the temp is. But can't you adjust the set
points so that the system runs cooler (but for longer)? (Or, could
you adjust the pump size or speed so the water has a longer residence
time in the radiators, thus returning cooler?)

Of course there is always uncertainty about gas prices going into the
future, which affects any such calculation. -- H

"Heathcliff" wrote in message
...
On Sep 17, 9:56 pm, Big_Jake wrote:
I did a little more research on the topic, and here is a pretty good
article on it. Looks like the answer is that a "condensing" boiler
operating at high temps is only about 88% efficient, or about 4-6%
more efficient than reliable, long lasting, cast iron.

JK

Thanks for the info - what is the URL for the article?

I have cast iron radiators and big old iron pipes serving them - I
think the system was originally a gravity circulator. When the
weather gets good and cold and the unit runs for a while, the
thermometer on the boiler gets up to maybe 180 or 185; I assume that
is the temperature inside the unit, not the return temperature. I
don't know what the return the temp is. But can't you adjust the set
points so that the system runs cooler (but for longer)? (Or, could
you adjust the pump size or speed so the water has a longer residence
time in the radiators, thus returning cooler?)

Of course there is always uncertainty about gas prices going into the
future, which affects any such calculation. -- H


You can cut down the boiler temp on the operating aquastat, which will cause
the zone to take more time to satisfy it's thermostat. You can also get
outdoor reset devices like those made by Tekmar to adjust boiler temperature
for optimum efficiency depending upon outdoor temp and demand

"Heathcliff" wrote in message
...
Trying to get ahead of the curve here. Heating season is approaching
and my boiler is old. I doubt I will replace it until absolutely
necessary, but when it happens, I will need to decide what kind to
get. House is about 2400 sq ft and climate is fairly severe
(Chicago). Hot water heat, natural gas fired. Have separate water
heater for domestic uses. The boiler I have now is a Peerless unit
from the 1980s.

I see you can get units that are 95% efficient, with sealed combustion
chambers and stainless steel heat exchangers. All of those sound like
good ideas, but how are they in practice? Do your fuel bills drop?
Do they give trouble? Do they last? Are they worth the extra $$? --
H

Yes, they work and yes, the fuel consumption can drop considerably. Every
manufacturer has some good units, far more efficient that anything from the
80's. Last year I upgraded to an Energy Kinetics System 2000. For the
first few months I save 32% and with the summer hot water use only it will
be even more.

Be sure to check on rebates, low or no interest financing and so forth.
There is a $1500 tax credit if you do it this year too. With state
financing, I'm able to pay for my system strictly from fuel cost savings.
YMMV.

Bob Walsh had written this in response to
http://www.thestuccocompany.com/main...rs-395314-.htm
:
Condensing boilers are the most efficient boilers on the market. They
allow huge energy savings compared to conventional boiler versions, and
there are countries beginning to require the use of boilers to be of the
condensing type. Conventional boilers convert 60% or less of their fuel
into heat. The efficiency of new condensing boilers are above 90%. Talk
about huge energy savings. How condensing boilers works Condensing boilers
are named such because they "condense" the exhaust gases or the water
vapor present in those gases, extracting heat from it and reusing it in
the process, instead of letting gases and water vapor get away through the
flue.

The secret of these boilers is based on their brilliant designs, which are
the larger heat exchangers. Heat exchangers ensure maximum heat
extraction, and eventually, minimal losses of gases.
There are some restrictions concerning the type of condensing boiler, all
depending on your existing heating system at home.

This is where you will require the expert advice and services of a
registered boiler engineer. Installation should be done by a qualified
boiler engineer who is gas safe registered as they will able to advise you
on the best type of the condensing boiler fit for your home.

On Dec 18, 4:45*am, (Bob Walsh) wrote:
Bob Walsh had written this in response tohttp://www.thestuccocompany.com/maintenance/Re-Experience-with-high-e...
*:
Condensing boilers are the most efficient boilers on the market. They
allow huge energy savings compared to conventional boiler versions, and
there are countries beginning to require the use of boilers to be of the
condensing type. Conventional boilers convert 60% or less of their fuel
into heat. The efficiency of new condensing boilers are above 90%. Talk
about huge energy savings. How condensing boilers works Condensing boilers
are named such because they "condense" the exhaust gases or the water
vapor present in those gases, extracting heat from it and reusing it in
the process, instead of letting gases and water vapor get away through the
flue.

The secret of these boilers is based on their brilliant designs, which are
the larger heat exchangers. Heat exchangers ensure maximum heat
extraction, and eventually, minimal losses of gases.
There are some restrictions concerning the type of condensing boiler, all
depending on your existing heating system at home.

This is where you will require the expert advice and services of a
registered boiler engineer. Installation should be done by a qualified
boiler engineer who is gas safe registered as they will able to advise you
on the best type of the condensing boiler fit for your home.

Conventional boilers are about 82% efficent, huge savings no but long
term yes. The maximum operating efficency of condensing is near 140f,
by the time you reach 180 f % efficency drops about 5%. If radiators
were oversized so you could run 140f all the time they would run at
their potential.

"Bob Walsh" wrote in message
roups.com...
Bob Walsh had written this in response to
http://www.thestuccocompany.com/main...rs-395314-.htm
:
Condensing boilers are the most efficient boilers on the market. They
allow huge energy savings compared to conventional boiler versions, and
there are countries beginning to require the use of boilers to be of the
condensing type. Conventional boilers convert 60% or less of their fuel
into heat. The efficiency of new condensing boilers are above 90%. Talk
about huge energy savings. How condensing boilers works Condensing boilers
are named such because they "condense" the exhaust gases or the water
vapor present in those gases, extracting heat from it and reusing it in
the process, instead of letting gases and water vapor get away through the
flue.


Hi Bob

As you may or may not know that I am not HVAC person,

However I am Environmental test Equipment Tech.

I am interested how this works. It seems to me what you are

Saying that this boiler reusing its own discharge gases by looping

It back into combustion chamber m'I assuming these correctly

Or m'I all wet?





The secret of these boilers is based on their brilliant designs, which are
the larger heat exchangers. Heat exchangers ensure maximum heat
extraction, and eventually, minimal losses of gases.
There are some restrictions concerning the type of condensing boiler, all
depending on your existing heating system at home.

This is where you will require the expert advice and services of a
registered boiler engineer. Installation should be done by a qualified
boiler engineer who is gas safe registered as they will able to advise you
on the best type of the condensing boiler fit for your home.

Me, well, I block all posts from the Sucko Company. I
wouldn't believe anything there.

The problem with high efficiency heaters, is that the flue
gasses aren't hot enough to carry up the conventional
chimney. So, they add an inducer fan. The condensing comes,
because they are able to cool the flue gas enough to
condense much of the water vapor. That resulting liquid
condensate has to be drained some where. Sometimes outdoors,
and sometimes into a sanitary sewer.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Grumpy" wrote in message
...


Hi Bob

As you may or may not know that I am not HVAC person,

However I am Environmental test Equipment Tech.

I am interested how this works. It seems to me what you are

Saying that this boiler reusing its own discharge gases by
looping

It back into combustion chamber m'I assuming these correctly

Or m'I all wet?