Is there an average life that one can expect from a gas furnace? I have a
furnace that is at least 20 years old, and the exhaust motor is making the
same noise as the last time, when it needed replacement. That was a few
hundred dollars.

So, I am wondering if I should just replace the furnace with something more
efficient, rather than sink money into it. As I understand it, furnaces of
this vintage are only about 60% efficient.

On Apr 29, 4:53 am, "Buck Turgidson" wrote:
Is there an average life that one can expect from a gas furnace? I have a
furnace that is at least 20 years old, and the exhaust motor is making the
same noise as the last time, when it needed replacement. That was a few
hundred dollars.

So, I am wondering if I should just replace the furnace with something more
efficient, rather than sink money into it. As I understand it, furnaces of
this vintage are only about 60% efficient.

Why not run efficency numbers to help you decide they go to 96% and
VSDC motors save about 1/3 in electricity.

On Apr 29, 8:45 am, ransley wrote:
On Apr 29, 4:53 am, "Buck Turgidson" wrote:

Is there an average life that one can expect from a gas furnace? I have a
furnace that is at least 20 years old, and the exhaust motor is making the
same noise as the last time, when it needed replacement. That was a few
hundred dollars.

So, I am wondering if I should just replace the furnace with something more
efficient, rather than sink money into it. As I understand it, furnaces of
this vintage are only about 60% efficient.

Why not run efficency numbers to help you decide they go to 96% and
VSDC motors save about 1/3 in electricity.

Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.


http://hes.lbl.gov/hes/aceee/afue.html

On Apr 29, 11:03 am, "Buck Turgidson" wrote:
Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

http://hes.lbl.gov/hes/aceee/afue.html

I think the 25 year life span is maybe a little high but you also need
to check the heat exchanger for cracks which can send carbon monoxide
into your living space. The fact that you have had repairs in the
past and your efficentcy concerns make me think it is time for a new
one.

On Apr 29, 11:03 am, "Buck Turgidson" wrote:
Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

http://hes.lbl.gov/hes/aceee/afue.html

Interesting site. They claim:

"If your furnace is 20 years old or more, it probably has an AFUE of
just 50 to 60%. By 1990, the typical efficiency had risen to 80%. Some
models today have an efficiencies of 95% or higher!"

So, from 1987 to 1990 the typical new furnace went from 50-60%, to
80%? I don't find that credible.

And if that ain't bad enough, how about this gem:

"The highest efficiency models can cost a little more up front, but
you'll save on fuel bills. You may have to shop around; some
installers may charge as little as $100 more for the high-efficiency
models, others charge a lot more. "

Anybody find that credible?

wrote in message
ps.com...
On Apr 29, 11:03 am, "Buck Turgidson" wrote:
Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

http://hes.lbl.gov/hes/aceee/afue.html

Interesting site. They claim:

"If your furnace is 20 years old or more, it probably has an AFUE of
just 50 to 60%. By 1990, the typical efficiency had risen to 80%. Some
models today have an efficiencies of 95% or higher!"

So, from 1987 to 1990 the typical new furnace went from 50-60%, to
80%? I don't find that credible.

And if that ain't bad enough, how about this gem:

"The highest efficiency models can cost a little more up front, but
you'll save on fuel bills. You may have to shop around; some
installers may charge as little as $100 more for the high-efficiency
models, others charge a lot more. "

Anybody find that credible?




Maybe not an accurate statement, but that doesn't necessarily make it
un-credible. A lot of people make statements without 'doing the math' - and
many fail to realize 1990 was almost 20 years ago! And there were some
pretty quick improvements to furnace efficiencies on the late 80's if I
recall.

I do agree that if this is really the exhaust blower that is going out then
it is probably higher in efficiency than 60%. And if so, replacing with a
new higher efficiency unit would probably not be justified in the fuel cost
savings.

Have the unit checked out by a reputable company. They would be better at
giving you feedback on the replace vs. repair cost, and if you end up
replacing they will probably apply the cost of the service call to the
replacement cost.

Buck Turgidson wrote:
Is there an average life that one can expect from a gas furnace? I
have a furnace that is at least 20 years old, and the exhaust motor
is making the same noise as the last time, when it needed
replacement. That was a few hundred dollars.

So, I am wondering if I should just replace the furnace with
something more efficient, rather than sink money into it. As I
understand it, furnaces of this vintage are only about 60% efficient.

I don't think I would put a lot of money into it. I would consider it
an opportunity to upgrade. You may or may not make the money back, but I
feel the current technology is good and I would not want to put good money
into a furnace that may be close to the end of it's life anyway.

--
Joseph Meehan

Dia 's Muire duit

wrote:

On Apr 29, 11:03 am, "Buck Turgidson" wrote:

Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

http://hes.lbl.gov/hes/aceee/afue.html


I think the 25 year life span is maybe a little high but you also need
to check the heat exchanger for cracks which can send carbon monoxide
into your living space. The fact that you have had repairs in the
past and your efficentcy concerns make me think it is time for a new
one.

Doesn't the life span depend on where it is? Here in the deep south,
furnaces are only used a few days out of a year. I suspect they last
a lot longer.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

On 29 Apr 2007 08:54:51 -0700, wrote:

On Apr 29, 11:03 am, "Buck Turgidson" wrote:
Don't know what vintage you are talking about, but I've never seen a
furnace with an exhaust blower that was only 60% efficient. Even a
run of the mill, cheap gas furnace has been 80% for decades. And
they have a lifespan of about 25 years.

http://hes.lbl.gov/hes/aceee/afue.html

Interesting site. They claim:

"If your furnace is 20 years old or more, it probably has an AFUE of
just 50 to 60%. By 1990, the typical efficiency had risen to 80%. Some
models today have an efficiencies of 95% or higher!"

So, from 1987 to 1990 the typical new furnace went from 50-60%, to
80%? I don't find that credible.

I think the problem is that there is no date on the page. They might
have written it 5, 10, 15 years ago, so that 20 years old might mean
1972!

He the link pointed to by the page
http://hes.lbl.gov/hes/aceee/furnace.html says "The ACEEE List of
Most Efficient Furnaces and Boilers: 1998" so that page is about 9
years old and maybe the other one is too. They mean 1978!

I've complained about this before, that so little on the Net has a
date. One would think the software for writing webpages would at
least put it in the source code, but I've never found it there. Not
this time either. The software isn't designed to put a date in, even
though lots of other software is. And here there is a valid need.

People no longer date their mail. That is, they put a date on a snail
mail letter, but rely on the computer to date email. This is fine
until someone copiess and pastes, or forwards without a dated
attribution line.

When I wanted to find a particular hamfest announcment, I found 6 of
them, all for different dates, and none listing the year. Only
because in this case I knew it was on Sunday was I able to figure out
which date was a Sunday *this* year.

And if that ain't bad enough, how about this gem:

"The highest efficiency models can cost a little more up front, but
you'll save on fuel bills. You may have to shop around; some
installers may charge as little as $100 more for the high-efficiency
models, others charge a lot more. "

Anybody find that credible?

"The highest efficiency models can cost a little more up front, but
you'll save on fuel bills. You may have to shop around; some
installers may charge as little as $100 more for the high-efficiency
models, others charge a lot more. "

Anybody find that credible?

No. Either that or they are noly referring to the labor portion of
the install cost, and not for the equipment. I would not buy one of
these high efficiency furnaces simply because I don't run my furnace
enough to justify the cost.