This Standard provides specific requirements and test methods for indirect gas-fired ducted air heaters which use natural gas (as described by AS 4564), town gas, liquefied petroleum gas (LP Gas, as described by AS 4670), simulated natural gas (SNG) and tempered liquefied petroleum gas (TLP) as a fuel, with an energy input not exceeding 500 MJ/h.For New Zealand:(a) The fuel gases are natural gas (as specified in NZS 5442) and general product liquefied petroleum gas (NZLPG) (as specified in NZS 5435).(b) The thermal efficiency requirements are informative only, except where they relate to safety.NOTES: 1 Appliances falling within the scope of AS 2658 are not covered by this Standard.2 Other statutory or regulatory requirements may be applicable to a product that falls within the scope of this Standard. It is the responsibility of the manufacturer, importer or distributor (as appropriate) to ensure that products comply with such requirements.Appendix AA provides figures referenced in this Standard that are in addition to those in AS 5263.0.Appendix BB sets out additional requirements and variations to AS 5263.0, to provide for New Zealand requirements and practices. These variations to Part 0 may be overridden by variations in Sections 1–5 of this Standard.Test methods are set out in Appendices ZA, ZB and ZC (see Clause 1.4).