Gazing
at the
innards
of the newest
residential heating
and cooling
equipment is a
little like looking
under the
hood of a new
car. Gone are
the familiar
basic components
of
yesteryear such
as distributor
caps and simple
air filters. In
their place is a
jungle of electronics
and
m e c h a n i c a l
c o m p o n e n t s
intended to
boost performance
and to
control polluting
emissions.
For cars, the
technological
maze under the
hood has proved
remarkably reliable as long as it is serviced by a well-trained mechanic. For residential hvac appliances
the story is a bit more complex. Some appliances have enjoyed a relatively trouble-free evolution to
higher efficiencies. Heat pumps and air conditioners, for example, were not radically modified to