Coleman 7600 - Circulating Air; Fresh Air; Return Air

INSTALLATION
INSTRUCTIONS
2.
Cirt'ulating
air
-
Warm air
is distributed
through
the duct
system by
the circulating
blower
located at
the top
of the
furnace.
The
operation
of the
blower
is
controlled
by the
fan
switch
which senses
the
heat
inside the furnace.
This is an automatic
switch,
lo-
cated
inside the control
panel.
3.
Fresh air
-
Some coaches,
due
to
location, may
have an excessive
moisture
problem. ln some cases
the moisture
problem
may be so
bad that condensa-
tion
may cause
water spotted
walls or ruined
paint
jobs.
When the air
is warrn, the
moisture
in
the
coach
is
invisible.
Since
warm air can
hold
more
moisture than
cold air, air containing
too
much
water vapor condenses
to
form frost or
water when-
ever
it
comes
in
contact
with
a
cold surface.
One of
the most common
illustrations
of
visible condensa-
tion
in the coach
is
the
formation of water
or
frost
on the
windows.
Cooking,
washing, bathing,
etc., all add
moisture
to
the air,
and
large amounts show
up as
condensation.
The small
rectangular chute
on the
bottom of the
furnace brings
in fresh air
to the circulating
blower.
The fresh air
which
is brought
into the circulating
blower
is
then distributed
as
warm air
through the
duct system.
This cool outside air,
after
being
warmed,
is
capable
of absorbing
moisture,
thus
helping to reduce condensation.
Return
air
The louvers on
the
top
front
of the
furnace
admit
return air.
Return air
must be
pro-
vided
back
to the
circulating
blower
in order
to
provide
air distribution.
Do
not enclose
the
lurnace
or otherwise
obstruct
these
louvers.
To
'do
so will
cause
the
furnace
to limit and
go
to
pilot.
The Presidential
furnaces are
designed
to
give
superior air-handling
capabilities.
This results
in an
air
temperature
rise of
165'F. compared
to
the
200'F. rise that the Solar
Paks were designed
for.
lf
you
use
less than
200 square
inches
free
area
return
grille
you
are reducing
the air
flow across the
heat exchanger and
just
asking
for service
problems
resulting in high temperature
cycling
on
heating.
To
avoid
operational
problems
on the
7660
furnace,
the 7660-5491
return air
grille must
be
used.
This
grille
has
200 square
inches of free area
and the use
of less
free
area
can
result in operational
problems.
4
Figure
9.
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