1. Scope
1.1 These requirements apply to natural and liquefied petroleum gas-fired packaged furnaces designed and manufactured primarily for the purpose of building heating. 1.2 These requirements apply to a package furnace having a manufacturer's maximum input rating within the range of over 400,000 BTUH and up to and including 10,000,000 BTUH. Package furnaces series extending beyond 10,000,000 BTUH input may be investigated according to the intent of these requirements. 1.3 These requirements apply to a package furnace provided with automatic control devices and designed for automatic, semi- automatic or manual operation. 1.4 A furnace which complies with these requirements shall not be acceptable it it has features which impair the results contemplated by the requirements.