A zone is defined as a region of the building in which the air temperature and humidity are assumed to be uniform. A zone may be a single space, part of a space or a collection of spaces. Left clicking on the zones folder will display the zone names. Clicking one of the zone names will reveal the 'Zones' window which has the following values:
Name
The name the user has given to the zone. The user can edit this value by double clicking in the text box, typing in a new value and then moving onto another box either by using the <Tab> key or by left clicking in it.
Number
This is the number Tas has assigned to the zone. It cannot be changed by the user. It is sometimes used in controls functions and error messages.
Colour
The colour used to shade the zone in the 3D Modeller. This cannot be changed in the Tas Building Simulator.
Description
Details about the zone. The user can edit this value by double clicking in the text box, typing in a new value and then moving onto another box either by using the <Tab> key or by left clicking in it.
Floor Area
The floor area of the zone, computed from the data entered via Tas 3D Modeller. This cannot be edited by the user.
Volume
The internal volume of the zone, computed from the data entered via Tas 3D Modeller. This cannot be edited by the user.
Convection Co-efficient
This value is usually left blank. Any value entered will be applied to all zone surfaces. This is useful when simulating under-floor heating systems. There are also two options that can be selected from the drop-down box. 'External' will model the convection as if the zone was an external space and 'CEN' which allows the user to model to CEN standards.
Daylight Factor (%)
The daylight factor is defined as the average diffuse daylight on the space’s working plane as a percentage of the diffuse illuminance on a horizontal plane outside the building. A daylight factor will be required if you plan to use the lighting functions.
Output
If this option is ticked then the simulation data file will contain results for this zone. If it is unticked then the zone results will not be output to the TSD file but the zone and its internal conditions will still be included in the simulation. This box is checked by default.
Zone Maximum Load - Heating (W)
The heating capacity of the zone in Watts.
Zone Maximum Load - Cooling (W)
The cooling capacity of the zone in Watts.
Size Heating
The options for sizing the heating plant will be selected from a drop-down list and include 'Design Sizing', 'No Sizing', and 'Sizing'. These options are described below:
Design Sizing - this option is chosen when you want to run a design day simulation to size the heating load for the zone. The zone maximum load is then fixed and a dynamic simulation is carried out at this fixed heating load. The simulation data file will contain the results of the design day calculation and the dynamic simulation.
No Sizing - the heating load for the zone is not sized during the simulation, instead you will input a zone maximum load for heating which will be used in the calculations. This will be done for each zone individually.
Sizing - the zone maximum load for heating is sized during the dynamic simulation.
Size Cooling
The options for sizing the cooling plant will be selected from a drop-down list and include 'Design Sizing', 'No Sizing', and 'Sizing'. These options are described below:
Design Sizing - this option is chosen when you want to run a design day simulation to size the cooling load for the zone. The zone maximum load is then fixed and a dynamic simulation is carried out at this fixed cooling load. The simulation data file will contain the results of the design day calculation and the dynamic simulation.
No Sizing - the cooling load for the zone is not sized during the simulation, instead you will input a zone maximum load for cooling which will be used in the calculations. This will be done for each zone individually.
Sizing - the zone maximum load for cooling is sized during the dynamic simulation.
Warning - when sizing the heating plant, Tas ensures that the zone temperature achieves the lower limit in one hour. This gives a generous margin of over-capacity in many situations. Alternative sizing strategies may be investigated by running a simulation.
There are tabs showing 'Internal Conditions', 'IZAMs', and 'Surfaces'. They are described in the following sections.