Optimisation Design Variable

Accessed from Optimisation and Parametric Analysis Settings dialog

Design Variable

Variable type

Select the variable type from the browse list.

View the full list of variable types.

Natural ventilation/infiltration

Natural ventilation rate - Scheduled natural ventilation only.
Nat vent set-point temp - Requires a Natural ventilation system to have been included in the base model.
Nat vent max temp difference - Requires a Natural ventilation system to have been included in the base model.

Infiltration - Scheduled natural ventilation only. When this variable is applied infiltration is automatically activated in the optimisation simulations even if the Model infiltration model option is switched off in the base model.
Airtightness - Value range between 0 and 4 to cover the 5 Airtightness slider settings when using Calculated natural ventilation. When this variable is applied infiltration is automatically activated in the optimisation simulations even if the Model infiltration model option is switched off in the base model.
Crack template - Calculated natural ventilation only. When this variable is applied infiltration is automatically activated in the optimisation simulations even if the Model infiltration model option is switched off in the base model.
% External window opens - Calculated natural ventilation only

% Roof window opens - Calculated natural ventilation only
Vent area - the area of the auto-generated external vents (does not affect custom drawn vents) - Calculated natural ventilation only
Internal vent area - the area of the auto-generated internal vents (does not affect custom drawn vents) - Calculated natural ventilation only
Roof vent area - the area of the auto-generated roof vents (does not affect custom drawn vents) - Calculated natural ventilation only

Mixed mode switch off when raining - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode max wind speed - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode min temperature - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode max temperature - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode min enthalpy - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode max enthalpy - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode min dew point temperature - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Mixed mode max dew point temperature - When this variable is applied the Mixed mode natural ventilation option is automatically activated in the optimisation simulations even if the Mixed Mode Zone Equipment > Mixed mode on model option is switched off in the base model. Note however that the Natural Ventilation > On model option must still be manually set in the base model for mixed mode setting to be applied in the simulation.
Nat vent indoor min temp schedule -

External window operation schedule - Calculated natural ventilation only
Internal window operation schedule - Calculated natural ventilation only
Roof window operation schedule - Calculated natural ventilation only
Earth tube ventilation rate - When this variable is applied the earthtube option is automatically activated in the optimisation simulations even if the Earth Tube > Include earthtube option is switched off in the base model.

Limit value of opening nat vent modulation factor -
Nat vent modulation lower value of Tin-Tout -
Nat vent modulation upper value of Tin-Tout -

Glazing/shading

Glazing template -
Glazing type -
Facade type -
Window to wall % -
Window frame type -
Window blind type - When this variable is applied window blinds on external walls are automatically activated in the optimisation simulations even if the Window shading model option is switched off in the base model.
Window shading control schedule - When this variable is applied window blinds on external walls are automatically activated in the optimisation simulations even if the Window shading model option is switched off in the base model.
Local shading type - When this variable is applied local shading on external walls are automatically activated in the optimisation simulations even if the Local shading model option is switched off in the base model.

Internal glazing type -
Internal facade type -
% Internal glazing -
Internal window frame type -
% Internal window opens -
Roof glazing type -
Roof facade type -
Roof window frame type -
Roof shading coefficient -
Roof window blind type - When this variable is applied window blinds on roof surfaces are automatically activated in the optimisation simulations even if the Roof Window shading model option is switched off in the base model.

Roof window shading control schedule - When this variable is applied window blinds on roof surfaces are automatically activated in the optimisation simulations even if the Roof Window shading model option is switched off in the base model.

Activity/occupancy/comfort setpoints

Activity template -
Occupancy density -
Occupancy (Days/week) -
Heating set-point temperature -
Heating set-back temperature - Note that heating setback temperatures only apply when the Heating operation schedule includes values of 0.5 to indicate times of setback operation.
Cooling set-point temperature
Cooling set-back temperature - Note that heating setback temperatures only apply when the Cooling operation schedule includes values of 0.5 to indicate times of setback operation.
Heating set-point PMV - Only applies when using the 4-Fanger comfort option for the Temperature control option for a Detailed HVAC simulation.
Heating set-back PMV - Only applies when using the 4-Fanger comfort option for the Temperature control option for a Detailed HVAC simulation.
Cooling set-point PMV - Only applies when using the 4-Fanger comfort option for the Temperature control option for a Detailed HVAC simulation.
Cooling set-back PMV - Only applies when using the 4-Fanger comfort option for the Temperature control option for a Detailed HVAC simulation.

Mech vent set-point temp -
Mech vent max temp difference -

Mech vent rate per person -
Mech vent rate per area -

Constructions

Construction template -
Insulation - Pre-design construction and glazing data only. 0=Uninsulated, 1=Typical ref, 2=Energy code, 3=Best practice.
Thermal mass - Pre-design construction and glazing data only. 0=Light, 1=Medium, 2=Heavy.
External wall construction -
Flat roof construction -
Pitched roof construction (occ) -
Pitched roof construction (unocc) -
Semi-exposed ceiling construction -
Semi-exposed floor construction -
Ground floor construction -
External floor construction -
Internal floor construction -
Wall sub-surface construction -
Partition sub-surface construction -
Roof sub-surface construction -
External door construction -
Internal door construction -
Internal thermal mass construction - Construction used for hanging partitions and when a non-zero value has been entered for the zone internal thermal mass exposed area on the Constructions tab under the Internal Thermal Mass header.
Component block material -

Wall below grade construction -
Partition construction -

Basement ground floor construction -

Internal gains/lighting

Computer gains - When this variable is applied computer gains are automatically activated in the optimisation simulations even if the Computer > On model option is switched off in the base model.
Equipment gains - When this variable is applied Office equipment gains are automatically activated in the optimisation simulations even if the Office Equipment > On model option is switched off in the base model.
Miscellaneous gains - When this variable is applied Miscellaneous gains are automatically activated in the optimisation simulations even if the Miscellaneous > On model option is switched off in the base model.
Catering gains - When this variable is applied Catering gains are automatically activated in the optimisation simulations even if the Catering > On model option is switched off in the base model.
Process gains - When this variable is applied Process gains are automatically activated in the optimisation simulations even if the Process > On model option is switched off in the base model.
Lighting template -
General lighting gains - When this variable is applied general lighting gains are automatically activated in the optimisation simulations even if the General Lighting > On model option is switched off in the base model.
General lighting gains per light output -
Luminaire type -
Task lighting gains - When this variable is applied task lighting gains are automatically activated in the optimisation simulations even if the Task and Display Lighting > On model option is switched off in the base model.
External lighting -

All gains - Lumped construction and glazing data only

HVAC systems

Simple HVAC template (Simple HVAC) - Simple HVAC only.
HVAC template (Detailed HVAC) - Detailed HVAC only. Note that Detailed HVAC templates only support templates with a single HVAC zone group. The way that zones are allocated to the zone group is as follows. If the building is the target then all zones that don't use the <None> Simple HVAC template are included in the HVAC zone. Otherwise if individual zones are set as targets then only those zones are loaded to the HVAC zone group. In this case zones that are not included as targets will not be assigned an HVAC system and so will be unconditioned.
Mechanical ventilation rate -
Auxiliary energy - Simple HVAC only
Pump etc energy - Simple HVAC only
Boiler CoP - Simple HVAC only
Heating system seasonal CoP - Simple HVAC only
Cooling system CoP - Simple HVAC only
Cooling system seasonal CoP - Simple HVAC only

Heating operation schedule -
Cooling operation schedule -

Location/weather/orientation

Location template -
Hourly weather data -
Building orientation - adjusts the orientation of the building relative to the site. Note that component blocks that are part of the wider site are not rotated with the building but component blocks that are part of the building are. See under the help for Level setting under Component block settings.

Renewables

Load centre 1 - the load centre variables can be useful for varying the number of PV panels in a study. Set up and select a number of load centres each one having a different number of PV panels.
Load centre 2 - see Load centre 1
Load centre 3 - see Load centre 1
Load centre 4 - see Load centre 1
Load centre 5 - see Load centre 1

Other

Zone capacitance multiplier -

Custom

Custom IDF - special parametric variable type which acts on IDF variables within DB Erl / EMS.

Note: All variables are listed for selection regardless of the state of the model so care must be taken to select variables that are appropriate. For example, if the Scheduled natural ventilation model option is used then changes in the % External window opens variable (which only applies to Calculated natural ventilation) won't affect results.

Min value

The lowest value that this numeric design variable can take on. This option is only visible when a numeric variable type has been selected (above).

Max value

The highest value that this numeric design variable can take on. This option is only visible when a numeric variable type has been selected (above).

Step

Not used yet. This option is only visible when a numeric variable type has been selected (above).

Values

Click on the browse button to open a list of components or templates for selection. Items can be selected by checking the appropriate checkboxes.

When a template is selected as the variable type, one of the selected templates from the list are loaded in each iteration of the optimisation analysis.

This option is only visible when a list variable type has been selected (above).

Target

Target objects

This option allows you to select one or more object(s) to which the variations are to be applied.

The object(s) you select here are the places in the model where the variations will actually be applied. Normal model data inheritance rules apply so if you set the building as the target then the change will set for the building but will also inherit down to block, zone, surface and opening levels where appropriate. In this case any hard set data at block or lower levels will prevent inheritance in the normal way.