Lennox LGH300S User Manual

Page 14
HIGH ALTITUDE DERATE

At altitudes above 2000 feet, units must be derated to match gas manifold pressures shown in table below.
At altitudes above 4500 feet unit must be derated 2% for each 1000 feet above sea level.

TWO-STAGE
Gas Heat
Type
(Two-Stage)
Altitude - ft. Gas Manifold Pressure - in. w.g. Input Rate
Natural Gas or LPG/Propane - Btuh
Natural Gas LPG/Propane Gas First
Stage
Second
Stage
Low (L) No adjustment required
Standard (S) 2001 - 4500 3.4   
Medium (M) 2001 - 4500 3.4  234,000 345,000
High (H) 2001 - 4500 3.4  312,000 460,000
FOUR-STAGE
1
Gas Heat
Type
(Four-Stage)
Altitude - ft. Gas Manifold Pressure - in. w.g. Input Rate
Natural Gas or LPG/Propane - Btuh
Natural Gas LPG/Propane Gas First
Stage
Second
Stage
Third
Stage
Fourth
Stage
Low (L) No adjustment required
Standard (S) 2001 - 4500 3.4  84,000   
Medium (M) 2001 - 4500 3.4  117,000 234,000  345,000
High (H) 2001 - 4500 3.4  156,000 312,000 386,000 460,000
1

SPECIFICATIONS - GAS HEAT
Usage Data Model Number LGH156
LGH180
LGH210
LGH156
LGH180
LGH210
LGH240
LGH300
LGH180
LGH210
LGH240
LGH300
Heat Input Type Low (L) Standard (S) Medium (M) High (H)
Number of Gas Heat Stages 1 2 2 2
Gas Heating
Performance
(Two-Stage)
Input - Btuh First Stage   234,000 312,000
Second Stage N/A 260,000 360,000 480,000
Output - Btuh First Stage 135,000 - - - - - - - - -
Second Stage N/A 208,000 288,000 384,000
1
Gas Heating
Performance
(Four-Stage)
Input - Btuh First Stage N/A 84,500 117,000 156,000
Second Stage N/A  234,000 312,000
Third Stage N/A 214,000  
Fourth Stage N/A 260,000 360,000 480,000
Output - Btuh First Stage 135,000 - - - - - - - - -
Second Stage N/A - - - - - - - - -
Third Stage N/A - - - - - - - - -
Fourth Stage N/A 208,000 288,000 384,000
 15 - 45 15 - 45 30 - 60 40 - 70
󰀩 80.0% 80.0% 80.0% 80.0%
Gas Supply Connections 1 in. npt 1 in. npt 1 in. npt 1 in. npt
Recommended Gas Supply
Pressure - in. w.g.
Natural 7 7 7 7
LPG/Propane 11 11 11 11
1
Four-stage gas heating is enabled when zone sensor, Discharge Air Control, or fresh air tempering mode is selected. (Available when using the CS8500 thermostat or
when connected to Building Automation Systems using BACnet, LonTalk, or S-Bus protocols)

Lennox LGH300S Specifications

General

Brand	Lennox
Model	LGH300S
Category	Air Conditioner
Language	English