Mooney M20R - Cabin Ventilation System; Cooling; Heating; Special Tools

SERVICE
AND
MAINTENANCE
MANUAL
M20R
MOONEY
AIRCRAFT
CORPORATION
21-00-00
CABIN
VENTILATION
SYSTEM
cool
gas
which
passes
through
the
evaporator
coil
and
absorbs heat
from
the
warm
cabin
air
passing
over
the
The
cabin
environmental
system
consist
of
three
stan-
coils. The
warm
low
pressure
refrigerant
then
enters
the
dared
ventilating systems
that
supply
heated
or
fresh
air
R-134a
compressor
where
the
process
starts
all
over
as
the
pilot
or
passengers
prefer.
CABIN
AIR,
CABIN
again.
HEAT
and
OVERHEAD
VENTILATION.
The
cabin
air
and
heat
system
controls
and
vents
are
located
on
the
con-
In
addition
to
cooling
cabin
air,
a
refrigerant
type
system
sole
between
the
pilot
and
co-pilot
seats.
Individual
fresh
also
removes
a
large percentage
of moisture from
the air
air
outlets
are
located
on
each
side
of the
cabin
side
as
well
as
removing
dust
and
pollen particles
from
the air.
panels
just
forward
of the
pilots
and
co-pilots
outboard
The air
conditioning
system
consist
of various
compo-
knees.
The
overhead
ventilation
system
consists
of
indi-
nents
installed in
several
areas
of
the aircraft.
The
Com-
vidual
outlets
O~mac
valves)
located between
and
presser
Installation
located
on
the
rear
of the
engine
above
each
seat
position.
The
aircraft has
a
flow
regulator
accessory
case,
Switch Installation
on
the cabin
lower
system
with
the
control
knob
located above
and
between
console,
Evaporator
Installation
hat
rack,
Outlet Duct
the
pilot’s
and
cc-pilot’s
head.
The
systems
are
basically
Installation
over
head of the hat
rack,
Air Inlet
Installa-
trouble
free
but
inspection
should
be
made
at
regular
tion
tailcone
(RIH
access
panel),
Diffuser
Assembly
intervals
to
ensure
proper
operation.
tailcone
(R/H
access
panel),
Condenser
Installation
tailcone
(R/H
access
panel),and
Exhaust Duct
tailcone
21-40-00
HEATING
(R/H
rear).
Heat
is
supplied
to
the
cabin
through
flexible
hoses
con-
2151-00
SYSTEM
LEAK CHECK
nected
to
a
heat
distribution
box
assembly
and
a
PROCEDURE
(R-134a)
muff/shroud
assembly
located
on
the
exhaust
manifold
on
the
engine.
It
is
recommended
that
the
condition of
these
items
be
checked
each
time the
cowling
is
re-
Leak check
of
a
refrigerant plumbing
system
is
very
im-
moved.
This
will
provide
a
continuing
check for
the
pre-
portant
to
assure
that the
system
maintains its
charge
to
provide
the
designed
performance
and reduce
damage
vention
of carbon
monoxide
(CO)
in the
cabin.
Any
dete-
to
system
components.
Plumbing
systems
on
aircraft
are
riorated
flexible
ducts
should
be
replaced.
Heat
shrouds
very
hard
to
keep
leak
tight
due
to
the
type
of
gas
or
fluid
should
be
inspected
for
cracks
or
other
deteriorations
and
repaired
or
replaced promptly.
It is
recommended
used,
excessive vibration
and
expansions
or
contractions
due
to extreme
ambient
temperatures
and altitudes.
that
inspection
of the
exhaust
system
for
any
leaks
or
Therefore,
a
periodic
check of the
system
charge
is
re-
cracks,
at
each
maintenance
action,
be
made
and
re-
quired
to
determine
if
any
loss
or
refrigerant
has
oc-
place
components
or
repair
as
needed.
curred.
2150-00
COOLING
1. The
system
leak
check is
required
whenever
the
following
conditions
occur:
GENERAL
A. New
system
plumbing
installation.
The
type
of
cooling
system
installed
in
an
aircraft
oper-
ates
on a
closed
vapor
cycle
concept
using
refrigerant
B.
Component
replacement
in
the
plumbing
system.
(R-134a)
as
the
heat
absorption
media.
The
(R-134a)
Air
C.
Line
or
hose
rupture.
conditioning
System
cools the
aircraft
in the
same
man-
ner
as a
cooling
system
in
an
automobile
or
home.
How-
5151-01
SPECIAL TOOLS
AND/OR
ever,
one
major
difference
in
the
two
systems
is
that the
EQUIPMENT
REQUIRED
(R-134a)
system
contains
components
which
are
de-
signed
to
be
light
weight,
compact,
provide
high
perform-
ance
and
operate
at
extreme
altitudes
and
ambient
tem-
The
following
tools
andlor
equipment
are
required
to
leak
check
a
refrigerant plumbing
system.
peralures.
REFRIGERANT
(R-134a)
SYSTEM
OPERATION
1.
Gaseous
dry
nitrogen, regulated
source
(0-500 psig)
The
concept
of
air
conditioning
a
room,
cabin
or
cockpit
2.
R-134a
refrigerant charging
manifold
with
gauges
is
actually
very
simple.
Figures
21-1
and
21-2
show
the
and
hoses
refrigerant
and
electrical
schematic
for
a
typical
system.
3.
Electronic
leak detector
The
refrigerant
is
the
media
which
absorbs
and
rejects
the
room
or
cabin
heat.
By
continuous
recirculation
of the
4. R-134a
refrigerant,
30
Ib.
cylinder
warm
cabin
air,
heat
is
absorbed
in the
evaporator
mod-
5. R-134a
Refrigerant
oil,
(Ester
RL-SOOS)
ule(s)
and
is
rejected
to
the
outside
through
the
system
condenser.
V\hen
the
system
is
turned
ON
the
compres-
6.
Leak
check
fluid,
(soapy
solution)
sor
is
connected
to
the
drive
belt
through
an
electrically
7.
Assorted hand
tools
actuated
clutch.
The
compresso
r cc
mpresses
the R-l 34a
refrigerant
gas
to
a
high
pressure.
The
hot,
high pressure
8.
Hand and
eye
protection
gas
then
passes
through
the
condenser
coil where
it is
9.
Thread
sealant,
P/N 55431
(Loctite)
cooled
and
condensed
into
a warm
liquid
at
constant
pressure.
The
warm
liquid
is then
routed
into
a
receiver-
10. Hose
adapter (1/2
in. male
acme
to
1/4 in.
female
flare)
dryer
container
where the
liquid
and
any
remaining
gas
are
separated
and
any
moisture
is
absorbed.
The
warm,
2151-02
LEAK
CHECK
PROCEDURE
dry
liquid
is
then
directed
to
the
evaporator
module
ex-
pansion
valve where
the
high
pressure
liquid
is
expanded
1.
Remove,
if
required,
all
panels,
doors,
shrouds,
etc.
to
a
low
pressure.
The
expansion
process
creates
a
super
to
gain
access
to
component
being
leak
checked.
REV.
7-96
21-00-00
Island Enterprises