Zones

Overview

Within most Energy-Modelling programs including Hero, simulated spaces are defined & organised into Zones.

These Zones typically represents “Rooms” of a Building however they are more accurately described as any Space or Volume of Air that is independently modelled. In addition to normal “Rooms” such as Bedrooms & Kitchen there are a variety of Special Zones within Hero such as Roofspace Zones & Subfloor Zones (detailed below).

 Zones are the Parent object of the Floors, Ceilings & Walls, that are contained within them, and also the Zone’s Ceiling Fans & Penetrations

Within the Chenath Simulation Engine, the Zone holds all the information regarding not only the Floors, Ceilings, Walls, Openings & other Model objects but also the Internal Heat Gains (such as Appliances, Occupant & Lighting), it’s Heating & Cooling Thermostat Setpoints & Profile, and the operation of Shade & Natural Ventilation features within the Zone. The Heating & Cooling Results of a Simulation are measured at the Zone level, and it from this Zone Heating & Cooling Result that the Star-Rating is eventually derived from.

ZONES IN THE VISUAL VIEW

Creation

Zones are created within the Visual View using the Zone Drawing Mode.

Selecting

Zones can be Selected using the Select Parent Context-Menu Action ( Right-Click → Select Parent) or it’s shortcut ( Double Left-Click on a child such as Wall, Floor or Ceiling).

Deleting

Zones can be Deleted (after selecting them as described above) using the Delete keyboard shortcut, or Right-Click Context-menu action Delete or via the Zone Data-Grid’s Delete button.

ZONES IN THE DATA-GRID

Property	Description	Edited Within

Property	Description	Edited Within
Name	The Name of the Zone	Name Column
Type	The Zone Type such as Bedroom or Living Room or Unconditioned. Zone Type determines the Heating & Cooling Thermostat Setpoints & Profile as well as Internal Heat Gain impacts (see Resources. See the table below for all NatHERS Zone Types.	Type Column
Dwelling	The Parent Dwelling of the Zone. Can be changed if Zone was initially created within the wrong Dwelling.	Dwelling Column (if >1 Dwelling)
Volume	The Total Air Volume of the Zone (in m3). Can be Manually Overridden by Users if desired to enter custom Air-Volumes. Open Volumes are typically Automatically calculated by Hero. However there are situations where the User may wish to set their own Zone Volume figure due to unusual Zone geometry or other reasons. The Hero Automatic Volume calculations can become less accurate for Non-Rectangular Zones (e.g. Zones with lots of split walls, floating walls and/or raked ceilings). The Automatic/Manual Volume Column of the Zone Data-Grid allows Users to toggle between Hero or User Volume figures. Setting the Toggle back to Automatic will recalculate the Volume back to Hero’s calculated value	Volume & Volume Automatic Columns
Air Leakage	Total Air Leakage of all Penetrations within the Zone (in m3/hr) Note: Currently does not include Simulated Air-leakage from Room & Openings, just Penetrations (coming soon)	Air Leakage Column (hidden by Default)

Zone Types

Hero contains the following Zone Types, many of which are exactly the same as the NatHERS Technical Notes definitions with several exceptions.

ROOFSPACE ZONES

A Roofspace Zone is automatically created by Hero whenever a Ceiling is of an Attic Type (which sets the Adjacency Type of the Ceiling to Roofspace).

This Roofspace Zone is modelled as a separate Zone within Chenath to account for the complex interactions of radiation, ventilation & convection within such a space.

Roofspace Zones have two additional attributes beyond normal Zones that users should be aware of: a Shape & a Soffit Floor (and in future customisable Roofspace Walls)

Roofspace Shape

A Roofspace Zone can have several Shapes applied to it to approximate the volume and roof layout of the Zone, including:

Roofspace Walls

Roofspace Walls for Gable & Mono-Pitch Roofspace Shapes are created automatically by Hero but currently cannot be seen or edited by the User (coming soon). A Hip Roofspace Shape has no external walls in the Roofspace Zone.

Roofspace Soffit Floor

All Roofspaces have an optional Soffit Floor automatically created and shown in the Floor Data-Grid (not shown within Visual View). This Floor is used to allow users to approximate the effects of areas of Roofspace such as Eaves or Overhangs where Heat Transfer from the External Environment into the Roofspace Zone will occur.

Open

The Soffit Floor is shown initially with a 0m2 Area Floor (ie empty) in the Floor Data-Grid with Name “Roofspace 1 Soffit” etc.

To use the Soffit Floor, enter a manual area into the Area Column of the Floor Data-Grid. If you do not enter a non-zero area, then no Soffit will be modelled in the Simulation

The Soffit Floor can have Insulation added to it to reduce Heat Transfer into the space however the Assembly cannot be changed.

Roofspace Ventilation Rates

Each Roofspace Zone can have a variety of Ventilation Rates to approximate the openness & wind flow through the Zone.

These are changed within the Ceiling Data-Grid’s Roofspace Ventilation column. If one Ceiling connected to the Roofspace changes the Ventilation rate then all Ceiling Ventilation columns will update accordingly.

SUBFLOOR ZONES

A Subfloor Zone is automatically created by Hero whenever a Floors is of a Suspended Type with a Subfloor Adjacency Type.

This Subfloor Zone is modelled as a separate Zone within Chenath to account for the complex interactions of radiation, ventilation, ground-layer & convection within such a space.

Subfloor Zones can have customisable Subfloor Walls.

Subfloor Walls

An External Subfloor Wall will be automatically created for each External Wall on the normal Zone above.

Subfloor Walls are shown within the Wall Data-Grid typically with a “SF” prefix to their name.

The initial Total Height of a Subfloor Wall will be the Level Height, with a negative Base Height & a Top Height of 0mm to indicate it is lower than the Level relative height. Heights of Subfloor Walls however can adjusted within the Wall Data-Grid.

The Construction, Insulation, Colour can also be changed within the Wall Data-Grid as per normal walls.

Open

The Wall Data-Grid showing 4 External Subfloor Walls created automatically for a square single Zone on a Level with Height above Ground of 1m (1000mm).

Subfloor Ventilation Rates

Each Subfloor Zone can have a variety of Ventilation Rates to approximate the openness & wind flow through the Zone.

These are changed within the Floor Data-Grid’s Subfloor Ventilation column. If one Floor connected to the Subfloor changes the Ventilation rate then all Floors Ventilation columns will update accordingly.