On Wed, 8 Dec 2010 10:14:48 -0800 (PST), Mark
wrote:

You need to read the entire study at:
http://www.nrc-cnrc.gc.ca/obj/irc/do.../nrcc38443.pdf

yes anyone interested in this subject should read that...

and take note that the study system had the blower running 100% of
the time. When the furnace was not heating, the blower ran for
circulation. and the ECM motor ran much sloer in circ mode compared
to the standard blower so there was much less circulation and not
surprisingly less energy was used.
The blower speed was adjusted to provide the most efficient heat
transfer - and actually the best air flow as well. Running a squirrel
cage fan too fast can actually REDUCE circulation. I think that was
also explained in the article. That's also why restricted ducting is
such a big deal.

But if you turn the blower OFF when the furnace is off like most real
people do, then it is less relevant.

MOST people turn the blower off???
Not up here. Running the blower on low speed keeps temperatures even,
and makes the air filter a lot more effective.

and also note the part where the ECM blower caused gas consumption to
increase..

That was also explained - and I mentioned that in an earlier thread -
the higher efficiency of the blower means more gas is required - but
the cost per therm using gas is a lot lower than the cost per therm
for electric, so it is still a net saving.

I would say the facts are presented in this paper but the writer
slanted the conclusion in favor of the ECM.

Follow the money...

In the case of the National Research Council there is no money to
follow. They are neutral, and not funded by manufacturing or marketing
companies.
Mark