5.9 Energy Recovery
5.9.1 Rotational Heat Exchanger (RotHExg21y)
The purpose of energy recovery is to absorb heat/cold from the exhaust air and
transfer it back to the supply air side. Energy recovery is usually used as the first
heating/cooling element. The control of the energy recovery can be advantageous
in the off-season depending on the required supply air temperature. Depending on
the setting and temperature conditions, the energy recovery unit can also be
selected so that it is only used for heating or for heating and cooling.
ERC is an active element that uses 0..10 V signal for wheel speed control. To limit
the PI control of the acceleration and deceleration of the ERC speed too slow or
too fast, the ramp-up/ ramp-down time can be set.
When configured, the bypass damper is automatically used to reduce the system
pressure differential at times when ERC is off (< 1% speed). The delay time to
activate the bypass after ERC is 1 min (fixed).
Available parameters
Current values
BACnet object
R/RW
Note
ERC speed
Prio2: Fire / Smoke
Prio5: Protection
RotHExgSpd
AO,106 (A1)
AO,115 (A2)
AO,124 (A3)
AO,133 (A4)
AVAL,385 (POS9)
AVAL,474 (AO1)
AVAL,481 (AO2)
RW
%
External fault detection for ERC
RotHExgFlt
BI,110 (X3)
BI,127 (X8)
BI,76 (D1)
BI,93 (D2)
R
Bypass damper
Prio2: Fire / Smoke
Prio5: Protection
HExgDmpBypCmd
BO,55 (Q1)
BO,70 (Q2)
BO,85 (Q3)
BVAL,246 (POS9)
RW
%
Setpoint supply air temperature for heating
SpTSuHHExg
AVAL,159
R
°C
Setpoint supply air temperature for cooling
SpTSuCHExg
AVAL,160
R
°C
Heat exchanger heating / cooling state
Prio 8, 13: manual override
Prio 15: automatic change
HExgEcmSta
BVAL,181
RW
0: Heating
1: Cooling
Basic settings
BACnet object
R/RW
Note
Minimum ERC speed
RotHExgSpdMin
AVAL,162
RW
%
Special settings
BACnet object
R/RW
Note
Ramp up/down time, ERC speed
TiRmpRotHExg
PINTVAL,83
RW
s
ERC Kp
GainHExgCtr
AVAL,165
RW
%/K
Application functionalities
Energy Recovery
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