Sensible Heating Mode; Ventilation Only Mode - Trane DX Application Manual

SYS-APG001A-EN

Sensible heating mode

If the outdoor air dew point is lower than, or equal to, the Dehumidification
Enable Setpoint, and the outdoor air dry-bulb temperature is lower than the
Heating Enable Setpoint, the unit operates in the Sensible Heating Mode
(Figure 12). In this mode, heater capacity is staged/modulated to warm the
outdoor air (OA) to the desired leaving-air dry-bulb temperature (CA).
Figure 12. Sensible heating mode
45
40
35
30
OA
30 35 40 45

Ventilation only mode

If the outdoor air dew point is lower than, or equal to, the Dehumidification
Enable Setpoint, and the outdoor air dry-bulb temperature is lower than the
Cooling Enable Setpoint but warmer than the Heating Enable Setpoint, the
unit operates in the Ventilation Only Mode. In this mode, the fan continues to
operate, but both the compressors and heater are turned off.
Dedicated Outdoor Air Systems: Trane DX Outdoor Air Unit
Control of the Dedicated OA Unit
85
sensible cooling
80
75
70
65
60
55
CA
55 60 65 70 75 80 85
dry-bulb temperature, °F
180
160
80
140
75
120
70
100
65
80
60
55
60
45
40
40
30
20
20
0
0
90 95 100 105 110
15