Air Flow; Temperature Rise Check - Napoleon 9700 SERIES Installation And Operating Instructions Manual

18.0

AIR FLOW

For proper furnace operation, air fl ow over the heat exchanger is of utmost importance. Insuffi cient airfl ow
accelerates metal fatigue and possible failure in the heat exchanger, and decreases effi ciency. Excessive
airfl ow promotes accelerated corrosion of the heat exchanger.
IMPORTANT:
DO NOT BYPASS THIS STEP OF THE
START UP PROCEDURES.

18.1 TEMPERATURE RISE CHECK

When the duct system is complete and the air fi lter or fi lters are in place, determine if the airfl ow is correct for both
low and high fi re input rates.
1. Insert a duct thermometer in the supply air duct. The thermometer should be placed as close as practical
to the furnace, but out of the "line of sight" of the heat exchanger (this prevents false readings owing to
radiant heat). Ensure that the thermometer location is within the duct air stream. Avoid locations such as
the inside radius of an elbow, etc.
2. Insert a duct thermometer in the return air duct as close to the furnace as practical. Ensure that the
thermometer location will be unaffected by humidifi er bypass ducts, etc. Choose a location well within the
main air stream.
3. Operate the furnace long enough to obtain steady state conditions at both input rates (High Fire and Low Fire).
4. When the two thermometers have stabilized, usually within 5-8 minutes, compare the two readings.
Subtract the return air temperature from the supply air temperature. The difference is the temperature rise,
also called ∆T.
5. Compare the measured ∆T to the temperature rise range shown on the rating plate.
Unless stated differently on the rating plate, the temperature rise should normally range between 35° to 65°F High
Fire, 20° to 50°F Low Fire. When adjusting the temperature rise, the ideal temperature is approximately mid-range.
If the measured ∆T is above the approved temperature range, there is too little air fl ow. It must be increased
by selecting the appropriate "HEAT"
jumper setting, removing restrictions
in the ductwork, or adding supply or
return ductwork.
If the measured ∆T is too low, there
is too much air fl ow.
TABLE 1 - RANGE OF TEMPERATURE RISE
Furnace Models
TABLE 7A - AIR FLOW (Y1-LOW COOL)
ECM 2.3 ESP 0.1" to 1.0" w.c.
A/C ADJUST COOL
Input
Tonnage Jumper Jumper
A
B
60000 N/A NORM
C
D
A
B
80000 N/A NORM
C
D
A
B
100000 N/A NORM
C
D
A
B
120000 N/A NORM
C
D
NOTE
Moving the ADJUST jumper from the NORM position to the (+) or (-) position
will increase or lower the CFM by 15%. Airfl ow based on approximately 375
CFM/Ton. Refer to Figure 39.
Temperature Rise
High Fire (HF) 35 - 65°F
ALL
Low Fire (LF) 20 - 50°F
TABLE 7B - AIR FLOW (Y2-HIGH COOL)
ECM 2.3 ESP 0.1" to 1.0" w.c.
Max A/C ADJUST
CFM Input
Tonnage Jumper
675
564
60000 3 Ton NORM
N/A
N/A
675
564
80000 3 Ton NORM
N/A
N/A
1050
840
100000 5 Ton NORM
630
N/A
1050
840
120000 5 Ton NORM
630
N/A
47
COOL
CFM
Jumper
A 1125
B 940
C 750
D 560
A 1125
B 940
C 750
D 560
A 1750
B 1400
C 1050
D 700
A 1750
B 1400
C 1050
D 700
W415-1064 / 11.11.11