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.