AIR FLOW
T
he importance of proper air flow over the
heat exchanger cannot be over
emphasized.
!,!+!%('*,&,, , -,
+1+,%+!2&!&+,$$
'*, +(!!(($!,!'&1
(*'(*$1(($1!&,
((*'(*!,!&-+,*1(,
+,&*!$++, &%!&!%-%
+,&*+*(($!,
)-!(%&,-+*'-$0(,
,'0(*!& ! *-,!$!,1
!$$+%"'*'%('&&,
!$-*.*1!&*+'!*
&'!+'*', *-&+,!+,'*1
!++-+'.*/ ! ,
%&-,-** +&''&,*'$
,%(*,-**!+ #
To determine if the air flow is correct,
make a temperature rise check.
1. Insert a thermometer in the supply
air duct as close to the furnace as
possible yet out of a direct line from
the heat exchanger. See Figure 49.
2. Insert a thermometer in the return air
duct as close to the furnace as
possible.
3. Operate the furnace.
4. When the thermometer in the supply
air duct stops rising (approximately
five minutes), subtract the return air
temperature from the supply air
temperature. The difference is the
temperature rise.
5. Compare the measured temperature
rise to the approved temperature rise
range listed on the furnace name
plate. See Figure 50.
If the measured temperature rise is above
the approved range, the air flow is too
low. More air must be moved by speeding
up the blower, by removing restrictions in
the duct system, or by adding more
supply or return air duct. If the measured
temperature rise is below the approved
range, the air flow is too much. Use lower
speed tap on the multi-speed blower.
, %+-*,%(*,-*
*!++ '-$+$'+,',
%!$', +,,*&+
('++!$'*0%($!,
*!+*&!+,'*+
, %'+,!$*!+/'-$
*+, %!$', *!+
*&!&$$(($!,!'&+,
!-*
,%(*,-**!+%+-*%&,
!-*
,1(!$-*&&%($,
!
WARNING
!
!&+,$$*%-+,"-+,,
,%(*,-**!+,', !+
%!$('!&,+$'+$1+
('++!$$+',
,%(*,-**!++ '-$
&
.*'.'*$$
$'/, +,,*&
'!&+''-$-+
%,', ,
0 &*'*!&,*%!,,&,
'(*,!'&/ ! '-$
-+!&"-*1'*, &
/!$$.'!,
%&-,-**+/**&,1
'*, !+(*'-,
AIR CONDITIONING DIVISION
FORT SMITH, ARKANSAS
48
To Next Page
Loading...
