53
©
2014
Daikin
North
America,
LLC
Checking
Duct
Static
The
positive
static
reading
is
taken
at
the
furnace
supply
outlet,
and
must
be
read
between
the
furnace
and
the
cooling
coil
.
The
negative
static
reading
is
taken
at
the
furnace
return
duct
inlet,
and
must
be
read
between
the
furnace
and
filter
.
Take
duct
static
readings
through
test
holes
in
ducts
,
and
tape
up
holes
once
your
test
is
complete.
©
2014
Daikin
North
America,
LLC
Checking
Duct
Static
Supply
Air
Inclined
Manometer
Measure
Negative
Static
Return
Air
Steps
to
determine
total
external
static
pressure:
Inspect/replace
filter
in
furnace.
Install
an
inclined
manometer,
magnehelic,
or
digital
manometer
into
return
duct
of
furnace
closest
to
blower,
but
downstream
of
filter
.
Measure
the
negative
static
pressure
of
the
return
duct
at
the
inlet
of
the
furnace
.