User Manual

12/28
Siemens Reservation and energy management CM110602en
Building Technologies Energy management without FOS 09/30/2008
3 Energy management without FOS
The energy management component of the HOTEL SOLUTION system is designed to
reduce the energy costs associated with heating and cooling guest rooms. With their
intelligent software, the room controllers provide some options themselves.
This section contains information about the possibilities offered by the room controllers
and describes how the hotel staff can manipulate them to obtain maximum benefit.
Please also read the description in Section 4, which describes some of the basic
concepts and principles for handling the dialog boxes.
To enable the energy management component to operate without a front-office
system, the "energy_with_fos" flag must be set to "FALSE" via the HOTEL
SOLUTION user interface (in the System | Configuration Parameters... menu).
3.1 Room controller options
The room controllers control the room temperature by comparing the measured room
temperature with the room temperature setpoint. This setpoint is set via the user
interface. Provided the hotel is fitted with the appropriate building services technology,
the room will be heated or cooled based on its deviation from the temperature setpoint.
Guests have the facility to increase or reduce the setpoint by 2 K or 4 K. If they
leave the room, these personal settings are retained, but the economy offset
comes into operation.
A controller can be operated using the Summer strategy, the Winter strategy or
the Transitional (Autumn/Spring) strategy, set via the user interface. When a guest is
absent, the temperature in the guest room is controlled by the different strategies as
follows:
• No heating, even if the current temperature is below the temperature setpoint
• Cooling ON if the current temperature is above the temperature setpoint
• Heating ON if the current temperature is below the temperature setpoint
• No cooling, even if the current temperature is above the temperature setpoint
• Heating ON if the current temperature is below the temperature setpoint
• Cooling ON if the measured temperature is above the temperature setpoint.
In all cases, the guest must be absent from the room, as it is essential not to impair the
comfort of guests. The purpose of these strategies is to take advantage of the current
outside air temperature to achieve the setpoint. Since, in winter, it is normally colder
outdoors than indoors, rooms in which the temperature is above the setpoint will cool
down without the need to operate the cooling system. In summer, the opposite is true.
In the transitional seasons (Spring / Autumn), outdoor temperatures are variable, so
that either the heating or the cooling is switched on, as necessary.
When a room is allocated to a guest, the Comfort setpoint is set. This should always
represent a pleasant indoor temperature. When the guest is absent from the room, the
room controller can reduce the set temperature by an amount referred to as the
economy offset.
At a setpoint of 23 °C and an economy offset of 2 K (Kelvin), the heating will not switch
on until the room temperature reaches 21 °C.
The effect of the economy offset is to delay the heating or cooling. When
commissioning the system, the economy offset can be set individually for each room
using the room-controller commissioning tool.
STOP
Caution
Setpoint and measured
temperature
Individual setpoint
adjustment
Heating strategy
Summer strategy
Winter strategy
Transitional strategy
(Autumn/Spring)
Economy offset