On Sat, 17 Sep 2005 13:52:15 -0400, with neither quill nor qualm,
"George Willer" quickly quoth:


R values are less important when you are talking about log homes because
of the greater thermal mass. The logs just don't change temperature that
quickly. Slow to heat up, slow to cool down. 10" to 12" is sufficient, and
if properly constructed, there is no air flow through the wall. Forget R
value when talking log.
--
Steve Spence

Why forget about the loss? Because it upsets the misguided who think log
homes are a good idea? By your reasoning a medieval castle wouldn't be
difficult to heat because of the thermal mass. POPPYCOCK!

Someone tell Steve the R-value of logs is quite low.
http://www.eere.energy.gov/consumeri...heets/ca8.html

"The R-Value of Wood

An R-value (Btu/ft2/hour/oF) is the rating of a material's resistance
to heat flow. The R-value for wood ranges between 1.41 per inch (2.54
cm) for most softwoods to 0.71 for most hardwoods. Ignoring the
benefits of the thermal mass, a six inch (15.24 cm) thick log wall
would have a clearwall (a wall with no windows or doors) R-value of
just over 8. Compared to a conventional wood stud wall [3? inches
(8.89 cm) insulation, sheathing, wallboard, a total of about R-14] the
log wall is apparently a far inferior insulation system. Based only on
this, log walls do not satisfy most building code energy standards."

Larry Jaques wrote:
On Sat, 17 Sep 2005 13:52:15 -0400, with neither quill nor qualm,
"George Willer" quickly quoth:


R values are less important when you are talking about log homes because
of the greater thermal mass. The logs just don't change temperature that
quickly. Slow to heat up, slow to cool down. 10" to 12" is sufficient, and
if properly constructed, there is no air flow through the wall. Forget R
value when talking log.
--
Steve Spence

Why forget about the loss? Because it upsets the misguided who think log
homes are a good idea? By your reasoning a medieval castle wouldn't be
difficult to heat because of the thermal mass. POPPYCOCK!


Someone tell Steve the R-value of logs is quite low.
http://www.eere.energy.gov/consumeri...heets/ca8.html

"The R-Value of Wood

An R-value (Btu/ft2/hour/oF) is the rating of a material's resistance
to heat flow. The R-value for wood ranges between 1.41 per inch (2.54
cm) for most softwoods to 0.71 for most hardwoods. Ignoring the
benefits of the thermal mass, a six inch (15.24 cm) thick log wall
would have a clearwall (a wall with no windows or doors) R-value of
just over 8. Compared to a conventional wood stud wall [3? inches
(8.89 cm) insulation, sheathing, wallboard, a total of about R-14] the
log wall is apparently a far inferior insulation system. Based only on
this, log walls do not satisfy most building code energy standards."


Yeah, but it's just like a castle; all you have to do is pour enough
heat in to keep the walls 70F. Golly, what's so hard about that?

John

On Sun, 18 Sep 2005 13:30:25 GMT, Ed Earl Ross
wrote:

wrote:
Christina Peterson wrote:


The description Pete uses to describe the way our house conserves
temperature (it's cooler in summer too, though by Fall the logs are
thoroughly warm) is "heat sink". What you are calling thermal mass.

snip

The ASHRAE HOF says Hem Fir has 0.74-0.9 Btu-in/h-F-ft^2, ie about R1.2
per inch, and
snip

A 12" thick Hem Fir log wall with R1.2 per inch, has a total of
R14.4 insulation--about that of 2x4 stick wall with fiberglass
insulation.

Yes, and it was stated that the roof (ceiling) was insulated. A
major portion of the heat loss is thru the roof, simply because that
often comprises a major portion of the exposed area. Further, log
homes may tend to be more geometrically efficient, enclosing more
square footage for given exposed area of walls and roof. A square
shape is more efficient than a long rectangle, L-shape or T-shape.

Windows and doors tend to be lossy. If a log home tends to have fewer
windows and doors, that would help.

Theoretical R-values (measured in a laboratory) are useful for
estimating and rough predictions, but the real measure of an actual
structure is the annual energy bill for given setpoint temp and
degree days.

If a guy says his log home is comfy and costs no more to heat than a
comparably-sized stick house after having lived in each, I wouldn't
be so quick to say he's wrong -- unless he's wearing a wool
lumberjacket and long underwear while making the assertion.

On Sun, 18 Sep 2005 23:04:44 -0400, "George Willer"
wrote:

Sorry you perceive knowledge as arrogance, but I'm not surprised. After
all, you've demonstrated a poor ability for understanding. The laws of
physics are there for all who are willing to see. Try it some time.

George Willer

This disinterested observer doesn't perceive knowledge as arrogance,
George, but I do find your posts to be arrogant. Would you display
such execrable manners in a face-to-face meeting? Maligning another
of different opinion does not reinforce yours for me; it weakens
it. It's a ploy often used to convince others of a position that
cannot be proved, as in politics and religion -- which are a hell of
a long ways from physics.

Applying laws of physics to a grossly-simplified model is
pseudoscience at best and sophistry if actual evidence indicates
otherwise. That seems to be the case here. No engineer with any
integrity ignores evidence that goes counter to his theory, for that's
how significant discoveries are sometimes made -- and, more often,
errors found in the evidence or the theory.

We don't even have a grossly-simplifed model he no comparative
wall areas, roof areas, data on windows and doors, infiltration rates,
insolation rate, siting info as it relates to wind exposure, and so
on. ASHRAE data and mfrs specs for R value of insulation is useful
assuming "all other things are equal". There are a whole bunch of
"other things" that will not be equal between any two structures of
whatever construction.

No evidence (or even opinion) has been offered as to how offered
evidence (observed heating cost) was flawed, or that the offeror is
unable to tally up his bills or simply a liar.

The R-value the mfr specified for particular insulation is a relevant
parameter, but never the only parameter and may not even be the
dominant parameter. (See other post) Honeywell researchers found
that a great many variables had to be dealt with and accounted for to
achieve a computer model that would produce results resembling actual
test cases -- data carefully taken by trained technicians and
engineers in actual residential structures of a wide variety of design
and construction. It took several highly-competent engineers and
scientists several years to get it right. ASHRAE didn't have
anything remotely close to it, still doesn't AFAIK but I've been away
from it for a few years.

Steve, let this guy go. You will never convince him and there's no
need to do so. Thank you for your posts. I'll admit that I would
have thought that log construction might be colder than conventional,
but I'd now reserve judgement until I'd talked to some folks who had
actual living experience and some heating bills I might look at.

I'll note that there are plenty of log homes being built in northern
MN by people who can afford any form of construction they want. One
that I know of is being built by an engineer and founder of a
sucessful firm that does energy consulting.
It's a upscale place on Leech Lake. I'll bet he'll be bringing lots
of clients and customers there for marketing and tax writeoff.

Don,

You've made my point... thank you. My point was that the log construction
yields higher heat loss and therefore higher expenses IF AND WHEN THE ONLY
DIFFERENCE IS IN THE CONSTRUCTION OF THE WALLS. I haven't seen any posts
that indicate otherwise... except for those wishful thinkers who have log
homes. If that position offends you or is considered arrogant, that's just
too bad.

I'm sure you will now also admonish Steve Spence for his demeaning attitude
this subject.

George Willer

"Don Foreman" wrote in message
...
On Sun, 18 Sep 2005 23:04:44 -0400, "George Willer"
wrote:

Sorry you perceive knowledge as arrogance, but I'm not surprised. After
all, you've demonstrated a poor ability for understanding. The laws of
physics are there for all who are willing to see. Try it some time.

George Willer

This disinterested observer doesn't perceive knowledge as arrogance,
George, but I do find your posts to be arrogant. Would you display
such execrable manners in a face-to-face meeting? Maligning another
of different opinion does not reinforce yours for me; it weakens
it. It's a ploy often used to convince others of a position that
cannot be proved, as in politics and religion -- which are a hell of
a long ways from physics.

Applying laws of physics to a grossly-simplified model is
pseudoscience at best and sophistry if actual evidence indicates
otherwise. That seems to be the case here. No engineer with any
integrity ignores evidence that goes counter to his theory, for that's
how significant discoveries are sometimes made -- and, more often,
errors found in the evidence or the theory.

We don't even have a grossly-simplifed model he no comparative
wall areas, roof areas, data on windows and doors, infiltration rates,
insolation rate, siting info as it relates to wind exposure, and so
on. ASHRAE data and mfrs specs for R value of insulation is useful
assuming "all other things are equal". There are a whole bunch of
"other things" that will not be equal between any two structures of
whatever construction.

No evidence (or even opinion) has been offered as to how offered
evidence (observed heating cost) was flawed, or that the offeror is
unable to tally up his bills or simply a liar.

The R-value the mfr specified for particular insulation is a relevant
parameter, but never the only parameter and may not even be the
dominant parameter. (See other post) Honeywell researchers found
that a great many variables had to be dealt with and accounted for to
achieve a computer model that would produce results resembling actual
test cases -- data carefully taken by trained technicians and
engineers in actual residential structures of a wide variety of design
and construction. It took several highly-competent engineers and
scientists several years to get it right. ASHRAE didn't have
anything remotely close to it, still doesn't AFAIK but I've been away
from it for a few years.

Steve, let this guy go. You will never convince him and there's no
need to do so. Thank you for your posts. I'll admit that I would
have thought that log construction might be colder than conventional,
but I'd now reserve judgement until I'd talked to some folks who had
actual living experience and some heating bills I might look at.

I'll note that there are plenty of log homes being built in northern
MN by people who can afford any form of construction they want. One
that I know of is being built by an engineer and founder of a
sucessful firm that does energy consulting.
It's a upscale place on Leech Lake. I'll bet he'll be bringing lots
of clients and customers there for marketing and tax writeoff.

On Mon, 19 Sep 2005 09:48:45 -0400, "George Willer"
wrote:

Don,

You've made my point... thank you. My point was that the log construction
yields higher heat loss and therefore higher expenses IF AND WHEN THE ONLY
DIFFERENCE IS IN THE CONSTRUCTION OF THE WALLS. I haven't seen any posts
that indicate otherwise... except for those wishful thinkers who have log
homes. If that position offends you or is considered arrogant, that's just
too bad.

I'm sure you will now also admonish Steve Spence for his demeaning attitude
this subject.

George Willer

No it wasn't. It was "why forget about the loss", a reasonable
question. The response was because fuel bills were similar in some
frame structures and one log structure. Then you got abusive.

Attributing low fuel bills to thermal mass is indeed incorrect, but
rather than helpfullly explaining why that is so (if you know), you
just became abusive. The fact that thermal mass does not explain
low fuel bills does not make the bills any higher. It just means
that the compared structure with less lossy walls (if that is the
case) has other leaks unaccounted for in a simple R-value calculation.

Mr. Spence's responses have been remarkably civil and restrained,
given the abuse sent his way.

On Mon, 19 Sep 2005 11:47:57 -0500, Don Foreman
wrote:

On Mon, 19 Sep 2005 09:48:45 -0400, "George Willer"
wrote:

Don,

You've made my point... thank you. My point was that the log construction
yields higher heat loss and therefore higher expenses IF AND WHEN THE ONLY
DIFFERENCE IS IN THE CONSTRUCTION OF THE WALLS. I haven't seen any posts
that indicate otherwise... except for those wishful thinkers who have log
homes. If that position offends you or is considered arrogant, that's just
too bad.

I'm sure you will now also admonish Steve Spence for his demeaning attitude
this subject.

George Willer

No it wasn't. It was "why forget about the loss", a reasonable
question. The response was because fuel bills were similar in some
frame structures and one log structure. Then you got abusive.

Attributing low fuel bills to thermal mass is indeed incorrect, but
rather than helpfullly explaining why that is so (if you know), you
just became abusive. The fact that thermal mass does not explain
low fuel bills does not make the bills any higher. It just means
that the compared structure with less lossy walls (if that is the
case) has other leaks unaccounted for in a simple R-value calculation.

Mr. Spence's responses have been remarkably civil and restrained,
given the abuse sent his way.



Hear hear Don! Steve's explanations have been reasonable and clear all through
the thread.

Mark Rand (just building the workshop with 6"PU foam SIP walls, roof and door,
8" concrete on 4" EPS floor and triple glazed windows)
RTFM