Napoleon 9600E E-STAR Series, Инструкция по установке и эксплуатации

Страница: 47 / 76

W415-2159 / D / 11.24.17
47
IOM
18.0 AIR FLOW
18.1 TEMPERATURE RISE CHECK
H22.0
For proper furnace operation, air fl ow over the heat exchanger is of utmost importance. Insuf fi cient air fl ow
accelerates metal fatigue and possible failure in the heat exchanger, as well as decrease ef fi ciency. Excessive
air fl ow promotes accelerated corrosion of the heat exchanger.
IMPORTANT:
DO NOT BYPASS THIS STEP OF THE
START UP PROCEDURES.
Model Delta T
NEV040T2A 35-65°F (20-36°C)
NEV060T3A
40-70°F (22.2-38.9°C)
NEV080T3A
NEV080T4A
NEV100T5A
NEV120T5A
H12.15.6A
TABLE 1 - RANGE OF TEMPERTURE RISE
When the duct system is complete and the air fi lter or fi lters are in place, determine if the air fl 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 humidi fi 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.
When adjusting the temperature rise, the ideal temperature is approximately mid-range on the rating plate.
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.
H22.1.4
18.2 CALCULATING AIR FLOW
H22.2.2B
CFM =
Output
1.085 x
∆ T
where:
• CFM is air fl ow in cubic feet per minute;
• ∆ T is the temperature rise; and
• O
utput is the furnace output capacity
from the rating plate
.
There are circumstances where it may be desirable to know the air fl ow delivery through the duct system,
such as when estimating the amount of air fl ow available for
air conditioning. This can be done by direct measurement with
electronic or sloped manometers and velometers, or by counting
the number of times the Amber CFM LED on the control board
fl ashes when equipped with ECM EON motor. Each fl ash
signi fi es 100 CFM; count the fl ashes and multiply by 100 to
determine the actual CFM delivered (for example: 10 fl ashes x
100 = 1000 CFM), or use the formula in the next column.