Yokogawa 212 Heat Calculator - Manual (Page 29)

3.6 OPERATING MODES
The Model 212 may be programmed to operate in either of four modes, as
follows:
1. Heating
2. Cooling
3. Heating/Cooling
4. Charge/Discharge.
3.6.1 Heating
Heating mode is used when the application is for Heating only and assumes that
the Feed Temperature will always be higher than the Return Temperature
(positive
∆
t). If the Feed Temperature is lower than the Return Temperature
(negative
∆
t), then no Energy is totalised, but Volumetric Flow is still totalised.
3.6.2 Cooling
Cooling mode is used when the application is for Cooling only and assumes that
the Feed Temperature will always be lower than the Return Temperature
(negative
∆
t). If the Feed Temperature is higher than the Return Temperature
(positive
∆
t), then no Energy is totalised, but Volumetric Flow is still totalised.
3.6.3 Heating/Cooling
Heating/Cooling mode is used where the flow of Energy may be for Heating or
Cooling. In this mode Energy is increased regardless of whether
∆
t is positive or
negative.
Operation 27