X-Staged Supply Air Operation - Lennox LGH094U Unit Information

TABLE 31
MINIMUM AND MAXIMUM CFM
094U4E, 122U4E, 152U4E
Gas Heat Minimum CFM
Unit Gas Heat Size
LGH094-152
LGH094-152
Electric Heat Minimum CFM
Unit Heat Size (kW)
LCH094
LCH094 0, 15, 22.5, 30, 45
LCH122, 152 15, 22.5, 30, 45
LCH122, 152
Cooling Low Minimum CFM - 160 CFM/ton
Unit Blower Speed
LGH/LCH094
LGH/LCH122
LGH/LCH152
Cooling High Minimum CFM - 220 CFM/ton
Unit Blower Speed
LGH/LCH094
LGH/LCH122
LGH/LCH152
Smoke and Ventilation Minimum CFM - 150 CFM/ton
Unit Not Applicable
LGH/LCH094
LGH/LCH122
LGH/LCH152
Heating and Cooling Maximum CFM - 480 CFM/ton
Unit Blower Speed
LGH/LCH094
LGH/LCH122
LGH/LCH152
*Rounded to nearest 25 CFM.
Airflow CFM*
Std. , Med. 2225
High 2550
Airflow CFM
7.5 1750
2750
2750
0, 60 3500
Airflow CFM
Low 1200
Low 1600
Low 2000
Airflow CFM
High 1650
High 2200
High 2750
Airflow CFM
NA 1125
NA 1500
NA 1875
Airflow CFM
High 3600
High 4800
High 6000

X-Staged Supply Air Operation

This is a summary of cooling operation for both belt and di­
rect drive blowers.
Note - During a dehumidification demand the blower oper­
ates at the highest speed. Free cooling is locked-out during
reheat operation. Refer to Hot Gas Reheat start-up and op­
eration section for details.
A-Two-Stage Thermostat
1-Economizer With Outdoor Air Suitable
Y1 Demand -
Compressors Off
Blower Cooling Low
Dampers modulate
Y2 Demand -
Compressors Off
Blower Cooling High
Dampers Modulate
Note - If dampers are at maximum open for three minutes,
compressor 1 is energized and blower stays on cooling
high.
2-No Economizer or Outdoor Air Not Suitable
Y1 Demand -
Compressor 1 On (on ultra high efficiency units,
Blower Cooling Low
Dampers Minimum Position
Y2 Demand -
Compressor 1 and 2 On
Blower Cooling High
Dampers Minimum Position
B-Three-Stage Thermostat OR Zone Sensor
1-Economizer With Outdoor Air Suitable
Y1 Demand -
Compressors Off
Blower Cooling Low
Dampers modulate
Y2 Demand -
Compressors Off
Blower Cooling High
Dampers Modulate
Note - If dampers are at maximum open for three minutes,
compressor 1 is energized and blower stays on cooling high.
Y3 Demand -
Compressors 1 and 2 On
Blower Cooling High
Dampers Maximum Open
Page 71
one compressor will operate)