Using the NVHR Grouping Scheme

Once you have imported one or both of the unit components from the library, a new Breathing Buildings NVHR® room grouping scheme will be created in your model and automatically selected in the room browser pane (if the pane is not visible at the bottom left of the VE window, you can display it using the  button on the application toolbar, or by selecting Browser from the File->View menu).

 

 

The NVHR grouping scheme is the mechanism used to assign an NVHR unit to a room in the model. The scheme contains one or more unit groups representing each unit type you have in your model – this will initially be the unit(s) you imported using the previous navigator action. There is also a final unit group called No NVHR Assigned – if a room is not being served by an NVHR unit, it is contained in this group (initially, all rooms in the model will be in this group).

 

Since all rooms assigned to a particular unit group will share the same NVHR properties (i.e. number of units in room, operation schedule, set-points and so on), you may want to create one or more duplicates to allow the same basic type of unit (ducted or un-ducted) to be used with different properties on each (e.g. a different number of units per room, or different setpoints). To duplicate a group, right-click on it in the grouping scheme and select the Duplicate item – this will then create a new unit group below the right-clicked group that can be edited and assigned to independently.

If you have unit groups that are no longer required, you can remove them to avoid clutter. To remove a unit group, right-click on it in the grouping scheme and select the Delete item.

 

 

If there are one or more rooms currently assigned to the unit group, they will need to be re-assigned before the group can be deleted. The software will prompt you to do this before you can proceed:

Clicking Cancel at this point will mean that the unit group is not deleted and the room(s) remain assigned to it. Clicking OK will re-assign the room(s) to the alternative unit group and then then remove the unit group.

All unit groups can be deleted (excluding the No NVHR Assigned group). Note that if the last “real” unit group is removed, the grouping scheme itself will be automatically removed and the following alert will be displayed:

 

 

The grouping scheme can be reinstated by importing one or both of the original components again.

 

You can view and edit the NVHR properties for each unit group (excluding the No NVHR Assigned group) by right-clicking on the group item and selecting Properties. This will display the Component Properties window, consisting of two tabs: Breathing Buildings NVHR® Properties and Information.

The Breathing Buildings NVHR® Properties tab allows you to control the settings that will be used to simulate NVHR in each room that is assigned to the unit group, as well as edit the basics of the unit group such as naming, number of units per room, whether it will highlight its assigned louvres and windows, and its colour (displayed next to it in the grouping scheme and used by opening highlighting and if the By Room Group option is selected in the View->Colour menu).

 

Name: Allows you to change the name of the unit group. Editing this name will also update the name of the associated component in the model’s component library.

In-use: Indicates whether the unit group is in-use (has one or more rooms assigned to it) or not in use (has no rooms assigned to it).

Colour: Displays the colour currently used by the unit group for highlighting. Clicking on the colour will display the standard colour picker window, allowing this colour to be changed.

 

 

Highlight NVHR® Openings: These options control whether rooms assigned to this unit group will highlight their attached louvre(s) and/or window(s). Louvres will be highlighted in full colour, while windows will be highlighted in a lightened version of the colour.

Note that the opening highlighting is only displayed if the Breathing Buildings NVHR® grouping scheme is active in the room browser.

No. of units: Sets the number of NVHR units that will be simulated in each room assigned to this unit group. This can be between 1 and 6 units (2 would be typical for a standard-sized classroom).

Operation: Lists modulating profiles (weekly or yearly only) that can be used to control the operation of the NVHR unit(s) in the room(s) assigned to this unit group. By default, the filtering on this list will only show profiles that include the Occupancy category or have no categories set. You can change the filtering options by clicking the  button.

There is also an additional option Use Room Occupancy. When selected, this means that the operation of the NVHR unit(s) will be determined by the occupancy profile for each assigned room. Note that if an assigned room does not have a defined occupancy (i.e. an internal gain of type People), it will be considered to be using off continuously (unoccupied).

CO2 Avg. Daily Target: Sets the average daily CO₂ target in parts per million (PPM) for each room assigned to the unit group.

Room Setpoint: Sets the temperature set-point for the occupied hours in room(s) assigned to the unit group.

Night Cool Setpoint: Sets the temperature set-point for the unoccupied hours in room(s) assigned to the unit group.

Heating Night Setback: Sets whether a heating night setback strategy is used for room(s) assigned to the unit group.

Windows Night Cooling: Sets whether windows night cooling is used for room(s) assigned to the unit group.

Use Mechanical Cooling: Sets whether mechanical cooling is used for room(s) assigned to the unit group.

Note that if there are already room(s) assigned to the unit group when you apply changes to one or more of these values, the updates will be applied to all currently assigned rooms.

The navigator action Adjust NVHR® operating parameters for the imported systems (as necessary) will simply cycle through all available unit groups, asking you whether you want to edit the properties or skip:

 

 

This is equivalent to right-clicking on each unit group in turn and clicking on Properties.