On Mon, 05 Nov 2007 06:56:42 GMT, PaPaPeng wrote:



I agree. BTU is BTU and you need a finite amount to feel comfortable.
There is more than enough emprical data to properly size a furnace for
a particular sized house. If the furnace is undersized it turns on
and off too often and the noise is a nuisance. Frequent cycling may
wear out the rotating parts earlier. If its oversized the room temp
tends to overshoot before it shuts off. All the fine tuning
electronics control doesn't really improve anything since the house is
a pretty big heat reservoir that doesn't heat up or cool that quickly
to make a difference on our sense of comfort. The higher efficiency
comes from extracting the most heat from the flame and this is evident
from the lukewarm exhaust gas at the PVC vent pipe. Old model furnace
exhaust have metal vents that are too hot to touch and that's valuable
heat going up the chimney. Turning the fan motor on more sensitive
settings or at different speeds is unecessary gadgetry and equipment
cost.


I dislike the idea of a PCB in the hot environment of a furnace as
this cooks the board. That's a pretty good revenue stream for the
furnace manufacturer but is as best marginal to the operating
efficiency of the furnace.

I am highly suspicious of Trane as this company has an over aggressive
independent sales force of retired persons of authority such as a
school principal or a police officer. That induces trust and a
reluctance on the "hit" to ask hard questions. The sales force works
on commission and are not employees, not the ones I have met so far.
They can rattle off claims and figures from their sales brochure like
it is the best thing since sliced bread. But when asked about the
technical details they admit they know nothing of how the furnace
works - that how come the exhaust is so much cooler - and on what
basis does it decide to run or not run the furnace at their
"efficiency" settings. I can't imagine anyone in any trade not being
curious about the inner workings of what they sell especially when
they were senior authorities in their previous jobs (aka not dumb).
But since their protestations of technical ignorance is so uniform
across all their sales reps I believe its Trane's company policy to
them to deny knowledge. To answer such questions would open up a can
of worms.

Go to a HVAC supplies shop to see how a high efficiency furnace is
constructed. Have an idea of how it is different from the older
designs. Then buy one that is similarly constructed and buy the
cheapest and simplest model of a specified BTU output. There is no
such thing as using inferior materials to make a bigger profit. All
furnaces must use specific materials for the critical parts like the
heat exchangers or face regulatory and financial ruin on many levels
should they turn out to be inferior and faulty. There is no new
technology in sensors or motors or materials which are sourced from
the same outside manufacturers anyway. There are no technical
breaktroughs that will differentiate one manufacturer's high
efficiency furnace from another. They are all designed to last 20
years if not more without fuss. If you disagree do tell me in which
area can a "cheap" manufacturer skim on to make the extra profit? Or
where Trane can add value worth several hundred bucks more.

I cal bul****, so much that this post is dripping with it. You are
either ignorant or stupid. Which is it?