scope:

PREFACE

This publication represents a standard for safe operation, substantial and durable construction, and acceptable performance of gas-fired gravity and fan type direct vent wall furnaces. It is the result of years of experience in the manufacture, testing, Installation, maintenance, inspection and research on appliances designed for the utilization of gas. There are risks of injury to persons inherent in some appliances that; if completely eliminated, would defeat the utility of the appliance. The provisions in this Standard are intended to reduce such risks while retaining the normal function of the appliance.

Nothing in this standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of direct vent wall furnaces, the construction and performance of which may exceed the various provisions specified herein. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, revisions may become necessary. When they are believed desirable, recommendations should be forwarded to the Chairman of Accredited Standards Committee Z21, 8601 East Pleasant Valley Road, Cleveland, Ohio 44131.

Safe and satisfactory operation of a direct vent wall furnace depends to a great extent upon its proper installation, and it should be installed, as applicable, in accordance with the National Fuel Gas Code, ANSI Z223.1; The Manufactured Home Construction and Safety Standard, Title 24 CFR, Part 8280, or when such standard is not applicable, the Standard for Manufactured Home Installations; ANSI A225.1/NFPA 501A; manufacturers* installation instructions; and local municipal codes