Modine Manufacturing DJE Installation And Service Manual page 13

P P E E R R F F O O R R M M A A N N C C E E D D A A T T A A
T T a a b b l l e e 7 7 - - A A i i r r T T e e m m p p e e r r a a t t u u r r e e R R i i s s e e - - M M o o d d e e l l s s D D J J E E
B B T T U U / / H H r r . .
M M o o d d e e l l N N o o . . I I n n p p u u t t O O u u t t p p u u t t
M M a a x x . . C C F F M M
D D J J E E 7 7 5 5 75,000 60,000
D D J J E E 1 1 0 0 0 0 100,000 80,000
D D J J E E 1 1 2 2 5 5 125,000 100,000
D D J J E E 1 1 5 5 0 0 150,000 120,000
D D J J E E 2 2 0 0 0 0 200,000 160,000
D D J J E E 2 2 2 2 5 5 225,000 180,000
D D J J E E 2 2 5 5 0 0 250,000 200,000
D D J J E E 3 3 0 0 0 0 300,000 240,000
D D J J E E 3 3 5 5 0 0
350,000 280,000
D D J J E E 4 4 0 0 0 0 400,000 320,000
Ratings are shown for elevations up to 2000 ft. For higher elevations, the input rating should be reduced at the rate of 4% for each 1000 ft. above sea level. Does
not apply in Canada – See rating plate.
Units approved for use in California by CEC when equipped with intermittent pilot ignition gas controls.
When high rates of CFM are used, the air distribution baffle may be removed to lessen the pressure drop through the duct furnace.
! CAUTION
D D O O N N O O T T E E X X C C E E E E D D M M A A X X I I M M U U M M T T E E M M P P E E R R A A T T U U R R E E R R I I S S E E
S S H H O O W W N N I I N N T T A A B B L L E E 7 7
Less than the minimum air flow (CFM) through the furnace
will cause the air temperature rise to exceed the maximum
allowed. Air through-put must be adjusted to within the
range specified on the unit rating plate.
U U n n i i t t S S e e l l e e c c t t i i o o n n a a n n d d P P r r e e s s s s u u r r e e D D r r o o p p
D D e e t t e e r r m m i i n n a a t t i i o o n n
Using the btu/hr output capacity and desired air flow (CFM)
determined from the building heat loss and/or make-up air
requirements, match the desired unit btu/hr output with a duct
furnace size shown in the performance table for duct furnaces.
Make sure the air temperature rise and cfm fall within the
range shown for the desired model size.
If one unit will not satisfy the design requirements, the units
may be installed in tandem, or in parallel such that multiple
units will, in combination, meet the desired performance.
Do not exceed the maximum temperature rise shown in the
above performance rating table. Less than the minimum air
flow (CFM) through the duct furnace will cause air
temperature rise to exceed the maximum rise allowed. The
maximum allowable final air temperature is 150°F. The
maximum allowed air temperature rise is 85°F (DJE300 and
350 have a 100°F maximum). Shown above are typical
applications for a single unit and other units installed in
tandem and in parallel arrangements with their resulting final
air temperatures.
Once the unit(s) size has been determined, it is necessary to
find the expected pressure drop through the duct furnace and
air temperature rise under the desired air flow conditions. Two
graphs are shown for each model size on pages 14 thru 16.
One graph shows air temperature rise curves and the other
graph shows the pressure drop curves. The pressure drop
curves on pages 14 and 16 show two sets of curves. One is
for units with an air distribution baffle (solid lines), and the
other is for units without an air distribution baffle (dotted lines).
A A i i r r T T e e m m p p e e r r a a t t u u r r e e R R i i s s e e T T h h r r o o u u g g h h U U n n i i t t ( ( D D e e g g r r e e e e F F ) )
W W i i t t h h o o u u t t A A i i r r B B a a f f f f l l e e
2 2 0 0 2 2 5 5 3 3 0 0 3 3 5 5 4 4 0 0
C C F F M M ( ( S S t t a a n n d d a a r r d d A A i i r r ) )
2778 2222 1852 1587 1389 1235 1111 1010 926
3704 2963 2469 2116 1852 1646 1481 1347 1235 1140 1058 988
4630 3704 3086 2646 2315 2058 1852 1684 1543 1425 1323 1235 1157 1089
5556 4444 3704 3175 2778 2469 2222 2020 1852 1709 1587 1481 1389 1307
7407 5926 4938 4233 3704 3292 2963 2694 2469 2279 2116 1975 1852 1743
8333 6667 5556 4762 4167 3704 3333 3030 2778 2564 2381 2222 2083 1961
9259 7407 6173 5291 4630 4115 3704 3367 3086 2849 2646 2469 2315 2179
11,111 8889 7407 6349 5556 4938 4444 4040 3704 3419 3175 2963 2778 2614 2469 2339
12,963 10,370 8642 7407 6481 5761 5185 4714 4321 3989 3704 3457 3241 3050 2881 2729
14,815 11,852 9877 8466 7407 6584 5926 5387 4938 4558 4233 3951 3704 3486
4 4 5 5 5 5 0 0 5 5 5 5 6 6 0 0 6 6 5 5
C C F F M M ( ( S S t t a a n n d d a a r r d d A A i i r r ) )
855
S S I I N N G G L L E E S S I I D D E E V V I I E E W W
1235 CFM
60°F. Entering
Air Temp.
T T A A N N D D E E M M S S I I D D E E V V I I E E W W
1852 CFM
20°F. Entering
Air Temp.
P P A A R R A A L L L L E E L L S S I I D D E E V V I I E E W W
5556 CFM
20°F. Entering
Air Temp.
I I f f t t h h e e d d e e s s i i r r e e d d a a i i r r t t e e m m p p e e r r a a t t u u r r e e r r i i s s e e i i s s a a b b o o v v e e 5 5 5 5 ° ° F F , , t t h h e e f f a a c c t t o o r r y y
s s u u p p p p l l i i e e d d a a i i r r d d i i s s t t r r i i b b u u t t i i o o n n b b a a f f f f l l e e m m u u s s t t r r e e m m a a i i n n i i n n p p l l a a c c e e . . I I f f t t h h e e a a i i r r
t t e e m m p p e e r r a a t t u u r r e e r r i i s s e e i i s s 5 5 5 5 ° ° F F o o r r l l e e s s s s , , t t h h e e f f a a c c t t o o r r y y i i n n s s t t a a l l l l e e d d a a i i r r
d d i i s s t t r r i i b b u u t t i i o o n n b b a a f f f f l l e e m m a a y y b b e e r r e e m m o o v v e e d d . . In these cases, (air
temperature rises below 55°F) removal of the air distribution
baffle will lower the pressure drop across the duct furnace and
may allow lower horsepower motors to be used for a specific
application.
D D e e t t e e r r m m i i n n i i n n g g U U n n i i t t P P r r e e s s s s u u r r e e D D r r o o p p
To determine the expected pressure drop across the duct
furnace, refer to the pressure drop curves shown on pages 14
thru 16 for the various duct furnace sizes.
E E x x a a m m p p l l e e
Determine the pressure drop across a size 100 duct furnace
with an air throughput of 2000 cfm, both with and without the
factory supplied air distribution baffle in place.
W W i i t t h h A A i i r r B B a a f f f f l l e e
7 7 0 0 7 7 5 5 8 8 0 0 8 8 5 5 9 9 0 0
794 741 694 654
926 871
100,000
BTU/HR
Output
60°F.
Temp. Rise
12" MIN.
150,000 150,000
BTU/HR BTU/HR
Output Output
60°F. 60°F.
Temp. Rise Temp. Rise
Preheat
Preheat
Unit
Unit
225,000
BTU/HR
Output
60°F.
Temp. Rise
225,000
BTU/HR
Output
60°F.
Temp. Rise
9 9 5 5 1 1 0 0 0 0
M M i i n n . . C C F F M M
2222
2593
120°F. Final
Air Temp.
140°F. Final
Air Temp.
80°F. Final
Air Temp.
1 1 3 3