Lennox Elite XC16 User Manual

Page 17
XC16 SERIES
OUTDOOR
COIL
TO
HFC−410A
DRUM
LOW
PRESSURE
COMPRESSOR
SUCTION LINE
SERVICE VALVE
TXV
GAUGE MANIFOLD
HIGH
PRESSURE
LIQUID LINE
SERVICE VALVE
FILTER
DRIER
OUTDOOR UNIT
(Uncased Coil Shown)
Figure 27. Typical Manifold Gauge Connection Setup
1. Determine the desired DTMeasure entering air temperature
using dry bulb (A) and wet bulb (B). DT is the intersecting value of A
and B in the table (see triangle).
2. Find temperature drop across coilMeasure the coil’s dry bulb
entering and leaving air temperatures (A and C). Temperature Drop
Formula: (T
Drop
) = A minus C.
3. Determine if fan needs adjustmentIf the difference between the
measured T
Drop
and the desired DT (T
Drop
–DT) is within +3º, no
adjustment is needed. See examples: Assume DT = 15 and A temp. =
72º, these C temperatures would necessitate stated actions:
Cº T
Drop
– DT = ºF ACTION
53º 19 – 15 = 4 Increase the airflow
58º 14 – 15 = −1 (within +3º range) no change
62º 10 – 15 = −5 Decrease the airflow
4. Adjust the fan speedSee indoor unit instructions to
increase/decrease fan speed.
Changing air flow affects all temperatures; recheck temperatures to
confirm that the temperature drop and DT are within +3º.
Delta−T
80 24 24 24 23 23 22 22 22 20 19 18 17 16 15
78 23 23 23 22 22 21 21 20 19 18 17 16 15 14
76 22 22 22 21 21 20 19 19 18 17 16 15 14 13
74 21 21 21 20 19 19 18 17 16 16 15 14 13 12
72 20 20 19 18 17 17 16 15 15 14 13 12 11 10
70 19 19 18 18 17 17 16 15 15 14 13 12 11 10
57 58 59 60 61 62 63 64 65 66 67 68 69 70
Temp.
of air
entering
indoor
coil ºF
INDOOR
COIL
DRY
BULB
DRY
BULB
WET
BULB
B
T
Drop
19º
A
Dry−bulb
Wet−bulb ºF
A
72º
B
64º
C
53º
air flowair flow
All temperatures are
expressed in ºF
Figure 28. Checking Indoor Airflow over Evaporator Coil using Delta−T Chart
WHEN TO CHARGE?
S Warm weather best
S Can charge in colder weather
CHARGE METHOD? Determine by:
S Metering device type
S Outdoor ambient temperature
REQUIREMENTS:
S Sufficient heat load in structure
S Indoor temperature between 70-80ºF (21−26ºC)
S Manifold gauge set connected to unit
S Thermometers:
− to measure outdoor ambient temperature
− to measure liquid line temperature
− to measure suction line temperature
APPROACH OR
SUBCOOLING
WEIGH-IN
64ºF (17.7ºC)
and BELOW
65ºF (18.3ºC)
and ABOVE
START: Determine how refrigerant is metered
TXV
Figure 29. Determining Charging Method
OUTDOOR AMBIENT
TEMPERATURE
(SECOND STAGE − HIGH
CAPACITY)

Lennox Elite XC16 Specifications

General

Brand	Lennox
Model	Elite XC16
Category	Air Conditioner
Language	English