Compensation; Summer Compensation - ABB i-bus KNX Product Manual

4.6

Compensation

4.6.1

Summer compensation

© 2009 Busch-Jaeger Elektro GmbH – A Company of the ABB Group
The fan coil ambient temperature controller with display has summer
compensation and winter compensation modes. Both are explained in detail
below.
To save energy and to maintain the temperature differential when entering
an air-conditioned building, you should adjust the room temperature in
relation to the external temperature in summer (summer compensation
in accordance with DIN 1946). The ambient temperature is increased
by adjusting "cooling setpoint comfort mode".
Raising the room temperature does not, however, mean that you heat up
the room. Rather the adjustment is intended to allow the room temperature
without cooling to increase to a specified value. This prevents an air-
conditioner from continuing to try to reduce the ambient temperature to
24 °C at an outside temperature of 35 °C.
However, an external temperature sensor that sends its measured values
to the KNX and therefore can be evaluated by the ambient temperature
controller with display is required to enable summer compensation.
The following parameters are available for summer compensation
- "summer compensation at lower outside temperature",
- "summer compensation at higher outside temperature",
- "summer compensation at lower setpoint offset" and
- "Summer compensation at upper setpoint offset".
The lower and upper outside temperature value specifies from and up
to which temperature a setpoint should be corrected.
The lower and upper setpoint offset specifies how many K the setpoint
should be adjusted during summer compensation in the parameters or
by the user.
Typical values for summer compensation are
- 20 °C: lower outside temperature
- 32 °C: upper outside temperature
- 0 K: lower setpoint offset
- 4 K: upper setpoint offset
This means that a floating setpoint increase from 0 to 4 K will be
implemented if the outside temperature increases from 20 °C to 32 °C.
Example:
Parameters for "cooling setpoint comfort" 25 °C are defined in the bottom
graph. With rising outside temperature the parameterised setpoint is
adjusted from an outside temperature of 20 °C from 25 °C to 29 °C.
The 29 °C is reached at an outside temperature of 32 °C. From there
the setpoint is no longer increased as the outside temperature continues
to rise.
98