Part 3.7.3 Heating Appliances
Appropriate Performance Requirements
Acceptable construction manuals
P2.3.3 is satisfied for a heating appliance if it is installed in accordance with one of the following:
* * * * *
Domestic solid-fuel burning appliances: AS/NZS 2918.
Acceptable construction practice
18.104.22.168 Open fireplace construction
An open fireplace must be constructed as follows (also see Figure 22.214.171.124):
All masonry must be constructed in accordance with Part 3.3.
The front hearth must be constructed of stone, concrete, masonry or similar material so that—
it extends not less than 300 mm beyond the front of the fireplace opening and not less than 150 mm beyond each side of that opening; and
its upper surface does not slope away from the back hearth.
The base of the back hearth must be constructed of stone, concrete, masonry or similar material and any combustible flooring or framing members must be situated not less than 150 mm from its upper surface.
The fireplace rear and side walls up to a height of 300 mm above the underside of the arch or lintel—
must be constructed in 2 separate leaves of solid masonry with an overall thickness not less than 180 mm thick, excluding any cavity; and
must not consist of concrete block masonry in the construction of the inner leaf; and
must be constructed of masonry units with a net volume, excluding cored and similar holes, not less than 75% of their gross volume, measured on the overall rectangular shape of the units, and with an actual thickness of not less than 100 mm.
The fireplace must be constructed on footings complying with 126.96.36.199.
FIRE PLACE CLEARANCE FROM COMBUSTIBLE MATERIALS
188.8.131.52 Chimney construction
The construction of a chimney must comply with Part 3.3 and the following:
The walls of the chimney above the level referred to in 184.108.40.206(d) must be lined internally to a thickness of not less than 10 mm with composition mortar parging.
The chimney or flue must terminate not less than 300 mm above the highest part of the building within a horizontal distance of 3.6 m of the chimney or flue (see Figure 220.127.116.11).
SECTION SHOWING HEIGHT AND POSITION OF CHIMNEY
18.104.22.168 Installation of insert fireplaces and flues
An insert fireplace and flue must comply with the following:
The insert fireplace must be tested and passed the tests required by AS/NZS 2918.
The insert fireplace must be fitted into a masonry fireplace (including chimney) constructed in accordance with Part 3.3.
The flue must be double skin and have been tested and pass the tests required by AS/NZS 2918.
TYPICAL INSTALLATION OF FIRE PLACE FLUE INSERTS
There must be a clearance of 50 mm between the outer flue and adjacent materials.
The flue must terminate in accordance with Figure 22.214.171.124.
126.96.36.199 Installation of free standing heating appliances
The installation of a free standing heating appliance must comply with the following:
The appliance must—
be installed with safety clearances determined by testing in accordance with AS/NZS 2918; or
be located not less than 1.2 m from adjoining walls (other than a masonry wall); or
have a heat shield between the adjoining wall (other than a masonry wall) and the heating appliance in accordance with Figure 188.8.131.52.
The heating appliance must be installed on a hearth—
where a heat shield is installed, in accordance with Figure 184.108.40.206.
The flue must—
have been tested and passed the tests required by AS/NZS 2918; and
be installed in accordance with Figure 220.127.116.11; and
terminate in accordance with Figure 18.104.22.168.
ACCEPTABLE LOCATION OF FREE STANDING HEATING APPLIANCES
|Diagram b.||PLAN VIEW|
ACCEPTABLE FLUE INSTALLATION DETAILS
|Note: Flue pipe size — 150 mm maximum (for other sizes see AS/NZS 2918).|
22.214.171.124 Installation of boilers and pressure vessels
The distance between the vent of any explosion relief device and any adjacent wall, roof, ceiling or other solid construction must be calculated in accordance with Table 126.96.36.199.
Table 188.8.131.52 MINIMUM CLEARANCES FOR EXPLOSION RELIEF
|Clearance from||Minimum Clearance (metres)|
|Adjacent wall or ceiling/roof||0.4(V/3)1/3 or 0.4 m, whichever is the greater|
|Two walls at right angles; or one wall and a ceiling/roof||0.6(V/3)1/3 or 0.6 m, whichever is the greater|
|Note: V is the internal volume of the boiler or pressure vessel being vented up to the connection of the flue.|
Building elements surrounding a boiler must be protected from any furnace heat by refractory material or effective air spaces so that—
steel elements do not exceed a temperature of more than 300°C; and
concrete elements do not exceed a temperature of more than 200°C; and
timber elements do not exceed a temperature of more than 150°C.
The requirements of 184.108.40.206 are limited to a boiler or pressure vessel heating appliance within a building. Therefore the provision does not apply to a boiler or pressure vessel outside of these limitations, such as a portable gas appliance.
provides the minimum clearance required which is based on the volume of the space being vented. The minimum clearance is determined by a formula which includes the volume of the space being vented.
The intention of the explosion relief provisions is that, in the event of an explosion, the extent of damage is limited.
The minimum clearance determined in the first row is 0.4 m from an adjacent wall or ceiling/roof.
The minimum clearance determined in the second row is 0.6 m from two walls at right angles, or one wall and a ceiling/roof. This scenario poses a higher risk of damage from over pressure experienced during a deflagration and therefore both the ventilation and clearances are increased.