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).

Modelled Zone Coverage

All Rooms within a Dwelling should be modelled as Zones including Class 10a Garages attached to the rest of the modelled Dwelling. (Note if unconditioned rooms such as stores or garages are not attached directly then they still may need to be modelled as shading objects)

For Class 2 Apartment Projects, Hero recommends modelling all Common Area spaces including Carparks & Corridors for complete coverage (see Corridor & Carpark Zone Type descriptions below)

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

Roofspace Zones & Subfloor Zones are automatically created by Hero when a Ceiling or Floor is changed to have a Roofspace or Subfloor Adjacency respectively.

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.

Don’t Try to Drag-Select all the objects of a Zone and Delete them to Delete a Zone. You shoul select the Zone as described above & then delete it.

ZONES IN THE DATA-GRID

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. 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.

Zone Type	Description
Kitchen/Living	Examples: Kitchen, Kitchen/Living, Kitchen/Dining NatHERS Technical Notes: “Any room shown on a plan as a kitchen or a kitchen combined with one or more living areas. This zone must include the main kitchen area and may include a lounge, meals or dining area. All dwellings must contain one main kitchen/living zone. There can be no more than one kitchen/living zone. All additional smaller kitchens/kitchenettes within the dwelling must be zoned as another zone type.”
Living	Examples: Living, Lounge, Dining, Family, Rumpus, Media, Theatre NatHERS Technical Notes “This is the default zoning for internal zones not covered by any other zone type. Daytime zones include studies (without a built-in wardrobe), gymnasiums, internal domestic lifts, indoor pool rooms, saunas, above ground wine cellars, walk-in pantries, storage areas or conditioned outdoor living areas capable of being fully enclosed (i.e. considered within the dwelling envelope). This zone type includes hallways and corridors (either fully enclosed by doors or open to other zones) as they are circulation areas that allow access to other zones. This includes zones such as ensuites or walk-in wardrobes that can be accessed by a hallway or corridor (e.g. a two-way bathroom accessible by both a bedroom and the hallway). This zone type could also include any living, lounge, dining, family, rumpus, media or home theatre room, if they are in addition to the two largest living areas. This zone may be selected when a laundry, WC, bathroom or powder room is not ventilated by a door or window on an external wall.”
Bedroom	Examples: Bedroom or Study with Wardrobe NatHERS Technical Notes “Any room shown on the plan as a bedroom, whether or not it has any built-in wardrobes. Bedroom zoning must also be used for a study with either a built-in wardrobe, walk-in wardrobe or attached ensuite. In this case, the ‘study’ becomes a bedroom zone with the built-in wardrobe part of the same zone. A walk-in wardrobe or ensuite is to be zoned as night-time.”
Day Time	Examples: Laundry or WC or Bathroom with No External Window/Door, Study, Hall, Corridor, Store, Pantry NatHERS Technical Notes “This is the default zoning for internal zones not covered by any other zone type. Daytime zones include studies (without a built-in wardrobe), gymnasiums, internal domestic lifts, indoor pool rooms, saunas, above ground wine cellars, walk-in pantries, storage areas or conditioned outdoor living areas capable of being fully enclosed (i.e. considered within the dwelling envelope). This zone type includes hallways and corridors (either fully enclosed by doors or open to other zones) as they are circulation areas that allow access to other zones. This includes zones such as ensuites or walk-in wardrobes that can be accessed by a hallway or corridor (e.g. a two-way bathroom accessible by both a bedroom and the hallway). This zone type could also include any living, lounge, dining, family, rumpus, media or home theatre room, if they are in addition to the two largest living areas. This zone may be selected when a laundry, WC, bathroom or powder room is not ventilated by a door or window on an external wall.”
Night Time	Examples: Ensuite, WIR accessed from Bedroom NatHERS Technical Notes “This applies to areas that can only be accessed from a bedroom or from a zone, which itself, is only accessed from a bedroom. These include ensuites, walk-in wardrobes, parent’s retreats and WCs accessed from an ensuite.)”
Unconditioned	Examples: Laundry or Bathroom or WC or Powder, with External Window/Door NatHERS Technical Notes “Every dwelling must have at least one unconditioned zone. Laundries, bathrooms, airlocks, WCs or powder rooms that have an external wall with at least one or more ventilation openings (window or door). If there are no rooms that fit this description, then the smallest daytime zone must be modelled as an unconditioned zone. An airlock is a small, relatively airtight space that can be modelled as unconditioned space if: - it is located at a dwelling entrance and - has one or more external walls and - has one or more internal walls and - has an external door and - has one or more internal doors, of which, only one opens to a conditioned zone. Where an area labelled as an ‘airlock’ does not meet the above conditions, it is to be modelled as a daytime zone. Underground cellars may also be considered an unconditioned zone.”
Unconditioned Garage	Examples: Unconditioned Garage NatHERS Technical Notes “Where a garage is shown on the documentation as attached to the dwelling, and does not have any heating or cooling indicated.”
Conditioned Garage	Examples: Garage with Heating and/or Cooling NatHERS Technical Notes “This zone type only applies when a garage has heating ducts, hydronic heating elements or air conditioners.”
Corridor (Class 2)	Hero models all Class 2 Corridors (whether they are Unglazed or Glazed as per NatHERS Definitions) as a single “Corridor” Zone Type to minimise user confusion & simplify Model creation. Hero decides automatically (based on whether the Corridor Zone has Glazing) as to whether to Simulate the Zone within Chenath as a Special Chenath “Glazed Corridor” Zone, or as Neighbouring Adjacency
Carpark (Class 2)	Examples: Basement, shared carpark (Class 2 or 4 only) NatHERS Technical Notes “Where there is a shared carpark underneath an apartment, and the carpark is equal to or greater than 50 per cent closed from the outdoor air, then the area directly under the apartment must be zoned as ‘shared basement carpark’. Where a carpark under the apartment is greater than 50 per cent open to the outdoor air then this zone must be modelled as ‘above outdoor air’. This zone type must only be used in Class 2 and 4 dwellings. (More information available in Table 3). This zone type must not be used when Class 2 dwellings have individual garages.”
Void	The Void Zone Type is used to model a special situation where a Zone resides over Multiple Levels. The Void Zone should be the Upper Zone. Modelling a Zone as a Void means that all of it’s child objects such as Walls, Ceilings & Openings are modelled as a Single Zone within Chenath. Note a Void Zone does not need a Hole across the entirety of it’s Floor, this is assumed automatically by Hero (though you can if you’d like, though it will have identical effects).

Special Zones

Description

Roofspace Zone

A Roofspace Zone automatically created by a Ceiling with a Roofspace Adjacency.

Zone Type cannot be changed within Zone Data-Grid

For further details see the below Roofspace Zone section

Subfloor Zone

A Subfloor Zone automatically created by a Floor with a Subfloor Adjacency.

Zone Type cannot be changed within Zone Data-Grid

For further details see the below Subfloor Zone section

ROOFSPACE ZONES

A Roofspace Zone is automatically created by Hero whenever a Ceilings 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 Shape

Description

Hip Roof

A Standard Hip Roof where all roof sections slope downwards to the Walls. Default 23 degree roof pitch.

Very common in Australian homes particularly for Volume Builders.

Gable

(Ridge-Line N to S & Ridge-Line W to E sub-types)

A Gable Roof that creates a Roofspace Air Volume between the Roof & Ceiling. Default 23 degree roof pitch.

Two end walls are created automatically by Hero on the North & South or West & East ends of the Roofspace Zone for N-to-S & W-to-S Gable Roofs respectively.

Roofs that are Gable Shape may be a Attic Type or a Flat Pitched Ceiling (with no Roofspace) depending on the Ceiling installation. Gable Roofs can occasionally have internal raked ceilings which should be modelled as a Flat Roof Type Ceiling Assembly and not an Attic Assembly.

Mono-Pitch (creating a Roofspace)

A single pitched roof (default is a North to South 10 degree pitch) similar to a Skillion roof but that explicitly creates a sizeable Roofspace Air Volume between the Ceiling & Roof lines.

Don’t confuse a Flat/Skillion Type Ceiling Assembly that has no Roofspace with a Mono-Pitch Roofspace Zone Shape.

A Mono-Pitch Roof has a large roofspace created by it’s construction whereas a Flat Skillion Roof will typically only be the depth of it’s Rafters (and Ceiling & Roof battens) and therefore is not creating a sizeable Roofspace Air Volume

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.

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.

Ventilation Rate	Description
Min Vent	Attic Roofspace with Minimal Roofspace Ventilation (e.g. no dedicated roofspace ventilation system)
Nat Vent	Naturally Ventilated Attic Roofspace (e.g. Eave Vents & Whirly Ventilator/Ridge Cap Vents)
Mech Vent	Mechanically Ventilated Attic Roofspace (e.g. Eave Vents & Powered Roof Ventilator)

Unsarked Tile Roofs

NatHERS Protocol & the Chenath Engine also impose a requirement for Unsarked Tile Roofs which are quite rare in new Australian housing that further increases roof-space ventilation rates in the Simulation. Hero detects this situation automatically. A prefix “Unsarked Tile” is added to the Roofspace Zone’s Ventilation Rate column if the Assembly Type is a Tile Roof & there is No Roof Insulation selected.

SUBFLOOR ZONES

A Subfloor Zone is automatically created by Hero whenever a Floorsis 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.

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.

Ventilation Rate	Description
Enclosed (Disc.)	A Completely Enclosed Subfloor with Subfloor Wall Ventilation to Minimum NCC Requirements, and No Air-Cavity through any Wall Cavities above into a Roofspace
Enclosed (Conn)	A Completely Enclosed Subfloor with Subfloor Wall Ventilation to Minimum NCC Requirements, with an Air-Cavity through any Wall Cavities above into a Roofspace
Open	Additional Ventilation to Subfloor above NCC Requirements
Very Open	Very well ventilated / highly open subfloor