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Home Guy

wrote:

The new furnace is a multispeed brushless DC motor

They are a heck of a lot more efficient than a crappy split cap
induction motor!!

Sometimes durability and longevity trumps efficiency.

Even if electric heat (on a per-therm basis) is twice the cost of
natural gas, that extra energy used by a PSC motor is beneficially used
by my house in the winter, and my PSC fan is running only maybe 25 to
33% of the time, not 100% of the time. In the summer, when my fan is
running more often, it's running at full speed - something that I would
also ask an ECM motor to do, and for which the ECM motor does not have
as much of an efficiency advantage over a PSC motor.

So I'll pay the net $100 a year in additional energy cost and never have
to worry about my PSC motor failing me for several decades - if ever.

Even after gov't rebates, forking out a minimum $2000 for a new furnace
is going to take years to recover that, with the ECM motor delivering
just $100 a year and the burners / heat-exchanger *maybe* giving me an
additional $200 a year in savings. And by the time I've made those
savings the furnace will be near the end of it's reliable life-span.