AS/NZS 3500.4.2:1997

1 - AS/NZS 3500.4.2:1997 NATIONAL PLUMBING AND DRAINAGE - HOT WATER SUPPLY SYSTEMS-ACCEPTABLE SOLUTIONS
4 - PREFACE
5 - CONTENTS
8 - FOREWORD
9 - SECTION 1 SCOPE AND GENERAL
9 - 1.1 SCOPE AND APPLICATION
9 - 1.2 REFERENCED DOCUMENTS
9 - 1.3 DEFINITIONS
9 - 1.3.1 Acceptable solution
9 - 1.3.2 Deemed to satisfy
9 - 1.3.3 Container
9 - 1.4 WATER QUALITY
10 - 1.5 EQUIVALENT PIPE SIZES
10 - 1.6 WATER TEMPERATURE
10 - 1.6.1 Storage temperature
10 - 1.6.2 Sanitary fixtures delivery temperature
11 - SECTION 2 MATERIALS AND PRODUCTS
11 - 2.1 SCOPE OF SECTION
11 - 2.2 AUTHORIZATION
11 - 2.3 LIMITS ON USE OF PIPES AND FITTINGS
11 - 2.3.1 Copper pipes
11 - 2.3.2 Copper alloy pipes
11 - 2.3.3 Copper alloy fittings
11 - 2.3.4 Galvanized steel
11 - 2.3.5 Polybutylene (PB)
12 - 2.3.6 Polyethylene (PE)
12 - 2.3.7 Cross-linked polyethylene (PE-X)
12 - 2.3.8 Polypropylene (PP-R)
12 - 2.3.9 Chlorinated polyvinyl chloride (CPVC)
12 - 2.3.10 Stainless steel
13 - 2.4 CISTERN (COLD WATER STORAGE TANK) MATERIALS
13 - 2.4.1 Copper
13 - 2.4.2 Galvanized steel
13 - 2.4.3 Stainless steel
13 - 2.4.4 Other materials
13 - 2.5 SAFE TRAY AND SAFE WASTE MATERIALS
13 - 2.5.1 Safe tray
13 - 2.5.2 Safe wastes
13 - 2.6 JOINTING
13 - 2.6.1 Elastomeric rings
13 - 2.6.2 Elastomeric gaskets
13 - 2.6.3 Silver brazing alloy
13 - 2.6.4 Soft solders
14 - 2.6.5 Filler rods for stainless steel joints
14 - 2.7 BEDDING AND BACKFILL
14 - 2.8 MISCELLANEOUS MATERIALS
14 - 2.8.1 Timber
14 - 2.8.2 Thermal insulation
14 - 2.8.3 External protective coatings
15 - SECTION 3 INSTALLATION OF COLD AND HOT WATER PIPINT AND CONTROLS
15 - 3.1 SCOPE OF SECTION
15 - 3.2 SAFETY PRECAUTIONS
15 - 3.2.1 Electrical earthing
15 - 3.2.2 Proximity to electrical cables and gaspipes
15 - 3.3 METHODS OF JOINTING
15 - 3.3.1 General
15 - 3.3.2 Prohibited methods
16 - 3.3.3 Threading
16 - 3.3.4 Compression-type fittings
16 - 3.3.5 Flanged joints
16 - 3.3.6 Jointing of stainless steel pipe and fittings
16 - 3.3.7 Alternative jointing
17 - 3.4 SUPPORT AND FIXING ABOVE GROUND
17 - 3.4.1 General
17 - 3.4.2 Brackets, clips and hangers
17 - 3.4.3 Prohibited supports
17 - 3.4.4 Spacing
17 - 3.4.5 Securing of pipes and fittings
17 - 3.5 LOCATION OF PIPING
17 - 3.5.1 Walls
18 - 3.5.2 Chases, ducts or conduits
19 - 3.5.3 Under concrete slabs
19 - 3.5.4 Protection during building construction
19 - 3.5.5 Floor or roof penetrations
19 - 3.5.6 Insulation of buried piping
19 - 3.5.7 Insulation of encased piping
19 - 3.6 PIPES IN WATER- CHARGED OR FILLED GROUND
19 - 3.7 CROSS-CONNECTION CONTROL AND BACKFLOW PREVENTION
19 - 3.8 CONTAMINATED AREAS
19 - 3.8.1 General
19 - 3.8.2 Installation
20 - 3.9 CORROSIVE AREAS
20 - 3.10 DEPTH OF COVER IN PUBLIC AREAS
20 - 3.11 DEPTH OF COVER IN PRIVATE AREAS
20 - 3.12 PROTECTION AGAINST FREEZING
20 - 3.12.1 Requirement for protection
20 - 3.12.2 Piping located outside buildings
21 - 3.12.3 Pipes located on metal roofs
21 - 3.12.4 Pipes located inside buildings
21 - 3.12.5 Insulation of piping
22 - 3.13 COLD WATER PIPING AND CISTERNS
22 - 3.13.1 General
22 - 3.13.2 Cold water cisterns (See Figures 4.1 and 4.2)
24 - 3.13.3 Safe tray for cold water cistern
24 - 3.13.4 Support for separately mounted cisterns
25 - 3.14 INSTALLATION OF HOT WATER SUPPLY
25 - 3.14.1 Layout and size
25 - 3.14.2 Identification
25 - 3.14.3 Provision for expansion
26 - 3.14.4 Gradient
26 - 3.14.5 Maximum rise of hot water supply pipes
28 - 3.14.6 Shower assemblies
28 - 3.14.7 Venting of secondary circuit
28 - 3.14.8 Terminal fittings
28 - 3.15 TEMPERATURE CONTROL DEVICES
28 - 3.16 THERMOSTATIC MIXING VALVES
30 - SECTION 4 INSTALLATION OF WATER HEATERS-GENERAL REQUIREMENTS
30 - 4.1 SCOPE OF SECTION
30 - 4.2 WATER HEATERS
30 - 4.2.1 Water heaters
30 - 4.2.2 Selection of anode
30 - 4.2.3 Working pressure
30 - 4.2.4 Auxiliary controls
30 - 4.3 LOCATION
30 - 4.3.1 Placement
30 - 4.3.2 Accessibility and clearances
30 - 4.3.3 Ventilation and fluing
30 - 4.4 PROTECTION AGAINST DAMAGE FROM LEAKING WATER
30 - 4.4.1 Concealed water containers
31 - 4.4.2 Unconcealed storage water containers
31 - 4.4.3 Safe tray construction
31 - 4.4.4 Safe wastes
31 - 4.4.5 Placement of water heater or cistern on a safe tray
32 - 4.5 SUPPORT
32 - 4.5.1 Support of water containers installed in a roof
32 - 4.5.2 Support of water containers installed above a roof
32 - 4.5.3 Support of water containers installed other than in a roof space or above a roof
33 - 4.5.4 Seismic restraints
33 - 4.6 CORROSION PREVENTION AND WEATHER PROTECTION
33 - 4.6.1 Water heater base-corrosion avoidance
33 - 4.6.2 Weather protection of externally installed water heaters
33 - 4.7 CONNECTIONS TO WATER HEATERS
33 - 4.8 PRESSURE RELIEF AND VENTING OF WATER HEATERS AND CONTAINERS
34 - 4.9 VALVES
34 - 4.9.1 General
34 - 4.9.2 Required set pressure of valves (for unvented water heaters)
34 - 4.9.3 Installation of valves
41 - 4.10 MULTIPLE INSTALLATIONS OF PRESSURE-TYPE STORAGE WATER HEATERS
41 - 4.10.1 General
41 - 4.10.2 Balanced flow conditions
42 - 4.10.3 Positioning and sizing of pressure control valves
43 - 4.11 MULTIPLE INSTANTANEOUS WATER HEATERS
43 - 4.12 TEMPERATURE/PRESSURE/ RELIEF AND EXPANSION CONTROL VALVE DRAIN LINES
43 - 4.12.1 Size and material
43 - 4.12.2 Interconnection of drain lines
43 - 4.12.3 Installation
44 - 4.12.4 Common stack discharge
44 - 4.12.5 Tundish drain lines
44 - 4.12.6 Areas subject to freezing
44 - 4.13 VENT PIPES
44 - 4.13.1 Installation
44 - 4.13.2 Termination of vent pipe
45 - 4.13.3 Cistern-fed water heaters (other than side-fed types)
45 - 4.13.4 Vented storage water heaters, inlet pressure- controlled
55 - SECTION 5 INSTALLATION OF SOLAR WATER HEATERS
55 - 5.1 SCOPE OF SECTION
55 - 5.2 GENERAL
55 - 5.2.1 Performance
55 - 5.2.2 Solar water heater
55 - 5.2.3 Location
55 - 5.2.4 Sizing
55 - 5.3 INSTALLATION OF SOLAR WATER HEATER CONTAINER
55 - 5.3.1 Solar water heater containers
55 - 5.3.2 Containers installed on or above a roof
56 - 5.3.3 Containers installed in a roof
56 - 5.3.4 Protection against damage from leaking water
56 - 5.3.5 Connection to containers
56 - 5.3.6 Pressure relief and venting of containers
56 - 5.3.7 Valves
56 - 5.3.8 Relief and expansion valve drain lines
56 - 5.3.9 Vent pipes
56 - 5.3.10 Supplementary heating connections
56 - 5.4 INSTALLATION OF COLLECTORS
56 - 5.4.1 Positioning
57 - 5.4.2 Provision for removal of collector
57 - 5.4.3 Mountings
57 - 5.4.4 Precautions
59 - 5.5 INSTALLATION OF CLOSE-COUPLED AND INTEGRAL SOLAR WATER HEATERS
59 - 5.5.1 General
59 - 5.5.2 Roof mountings and supports
59 - 5.6 THERMOSIPHON FLOW SOLAR WATER HEATERS WITH REMOTE CONTAINERS
59 - 5.6.1 General
59 - 5.6.2 Primary circuit flow and return pipes-Pipes and fittings
60 - 5.7 SOLAR WATER HEATERS WITH FORCED PRIMARY CIRCULATION
60 - 5.7.1 General
61 - 5.7.2 Primary circulation pump
61 - 5.7.3 Pump and controller installation
61 - 5.8 SOLAR WATER HEATERS USED AS PREHEATERS
61 - 5.8.1 General
61 - 5.8.2 Installation of solar preheaters-cistern-fed water heaters
62 - 5.8.3 Installation of solar preheaters-mains pressure and reduced-pressure water heaters
62 - 5.8.4 Suitable types of existing heaters
62 - 5.9 MULTIPLE SOLAR WATER HEATERS INSTALLATIONS
62 - 5.9.1 General
62 - 5.9.2 Thermosiphon systems-series connection
62 - 5.10 SUPPLEMENTARY HEATING
62 - 5.10.1 Thermal capacity
62 - 5.10.2 Drain connection
65 - SECTION 6 ENERGY SOURCES AND HEAT RETENTION
65 - 6.1 SCOPE OF SECTION
65 - 6.2 CONTROLLED ENERGY SOURCES
65 - 6.2.1 Electric supply
65 - 6.2.2 Gas-fired water heater installations
65 - 6.2.3 Oil-fired water heaters
65 - 6.3 WATER HEATERS WITH UNCONTROLLED ENERGY SOURCE
65 - 6.3.1 Installation
66 - 6.3.2 Supplementary external heating
66 - 6.3.3 Provision for drainage
66 - 6.4 ‘Not applicalbe’.
67 - SECTION 6A ENERGY EFFICIENCY
67 - 6A.1 SCOPE OF SECTION
67 - 6A.2 INSULATION
67 - 6A2.1 General
67 - 6A.2.2 General piping to be insulated
67 - 6A.2.3 Hot water system piping
68 - 6A.2.4 Insulation exposed to the weather
68 - 6A.3 HEAT TRAPS
72 - SECTION 7 HOT WATER SERVICES FOR THE DISABLED
72 - 7.1 SCOPE OF SECTION
72 - 7.2 GENERAL
73 - SECTION 8 TESTING AND COMMISSIONING
73 - 8.1 SCOPE OF SECTION
73 - 8.2 FLUSHING
73 - 8.3 TESTING
73 - 8.4 COMMISSIONING
73 - 8.5 OPERATING INSTRUCTIONS
74 - SECTION 9 OPERATION AND MAINTENANCE
74 - 9.1 SCOPE OF SECTION
74 - 9.2 GENERAL
74 - 9.3 MAINTENANCE OF HOT WATER SERVICES
75 - APPENDIX A - REFERENCED DOCUMENTS
78 - APPENDIX B - WATER ANALYSIS
78 - B1 WATER ANALYSIS
78 - B2 TOTAL DISSOLVED SOLIDS (TDS)
78 - B3 SCALING PROPERTIES
78 - B4 WATER pH
79 - APPENDIX C - TYPICAL RATES OF FLOW
80 - APPENDIX D - PREFERRED SIZES OF PIPE FOR NON- CIRCULATORY AVERAGE SINGLE-STOREY TYPE HOUSEHOLD INSTALLATIONS
81 - APPENDIX E - RECOMMENDATIONS FOR THE INSTALLATION OF UNRATED SOLAR HOT WATER SUPPLY SYSTEMS
81 - E1 GENERAL
81 - E2 VOLUMETRIC STORAGE CAPACITY
81 - E3 RECOMMENDED OPERATING TEMPERATURE
81 - E4 COMBINED TEMPERATURE/PRESSURE RELIEF VALVE
81 - E5 COLLECTOR/CONTAINER SIZE RATIO
81 - E5.1 Normal conditions
81 - E5.2 Non-optimum conditions
82 - APPENDIX F - RECOMMENDATIONS FOR THE INSTALLATION OF CLOSE-COUPLED AND INTEGRAL SOLAR HOT WATER SYSTEMS ON ROOFS
82 - F1 GENERAL
82 - F2 SUPPORT
82 - F2.1 ‘With pitch’ installations
82 - F2.2 ‘Against pitch’ installations
82 - F2.3 ‘Cross pitch’ installations
82 - F3 POINTS TO NOTE
85 - APPENDIX G - SOLAR HOT WATER SYSTEMS SUGGESTED COMPONENT SIZES (UNRATED SYSTEMS)
85 - G1 GENERAL
85 - G2 ANTICIPATED SOLAR FRACTION
85 - G3 SOLAR RADIATION DATA
90 - APPENDIX H - ESTIMATION OF SHADING OF COLLECTORS
90 - H1 GENERAL
90 - H2 SUN LOCATER
91 - H3 APPROXIMATE METHOD OF DETERMINING SOLAR ALTITUDE
95 - APPENDIX I - EFFECT OF INCLINATION AND ORIENTATION ON SYSTEM PERFORMANCE
104 - APPENDIX J - MAP OF REGIONAL BASIC DESIGN WIND SPEEDS
105 - APPENDIX K - AUSTRALIAN CLIMATE REGIONS
105 - K1 SCOPE
105 - K2 CLIMATE REGIONS
108 - APPENDIX L - NEW ZEALAND CLIMATE REGIONS
108 - L1 SCOPE
108 - L2 CLIMATE REGIONS
111 - AMENDMENT CONTROL SHEET

Specifies the requirements for the installation of domestic type water heaters using potable water. It includes aspects of the installation from, and including, the valves on the cold water inlet to any cistern or water heater and the downstream fixtures and fittings. The Standard applies to new installations as well as alterations, additions and repairs to existing installations.

This Standard sets out the requirements for the installation of domestic-type water heaters using potable water. It includes aspects of the installation from, and including, the valve(s) on the cold water inlet to any cistern or water heater and the downstream fixtures and fittings. This Standard applies to new installations as well as alterations, additions and repairs to existing installations.This Standard applies to the installation of the following types of water heaters which comply with Clause 4.2.1 or Clause 5.3.1: (a) Electric storage water heaters with a rated delivery of up to 630 L per heater. (b) Other types of storage water heaters with a capacity of up to 700 L per heater. (c) Heat exchange water heaters in accordance with AS 1361.NOTE: The reference to AS 1361 is made to positively identify the particular type of heat exchange water heater to which this Standard applies.(d) Instantaneous water heaters. (e) Other authorized water heaters.Illustrations used in this Standard are diagrammatic only and have been chosen without prejudice.Construction of hot water supply installations in accordance with this Standard is deemed to satisfy the requirements of AS 3500.4.1 and Clause G12, Water Supplies of the New Zealand Building Code.

Originated in part as AS CA51-1968.

Previous edition AS 3500.4-1994.

Jointly revised an redesignated AS 3500.4.2:1997.

Reissued incorporating Amendment No. 1 (October 2002).