Preface

This is the fourth edition of ANSI Z21.76, Gas-fired unvented catalytic room heaters for use with propane gas. It supersedes the previous editions published in 1994, 1991, and 1988.

Scope

1.1
This Standard applies to newly produced unvented catalytic room heaters (see Clause 3, Definitions), hereinafter referred to as heaters, constructed entirely of new, unused parts and materials, having input ratings up to and including 40,000 Btu per hour (11 723 W) for use with propane gas, except:

a) heaters suitable for installation in bedrooms are to have input ratings of 10,000 Btu (2 931 W) per hour or less; and

b) heaters suitable for installation in bathrooms are to have input ratings of 6,000 Btu per hour (1 758 W) or less.

Unvented catalytic room heaters for installation in bedrooms or bathrooms are to be wall-mounted.

The construction of unvented catalytic room heaters for use with propane gas is covered under Clause 4.

The performance of unvented catalytic room heaters for use with propane gas is covered under Clause 5.

1.2
If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification.

1.3
All references to psi throughout this Standard are to be considered gauge pressure unless otherwise specified.

1.4
Clause 2 contains a list of standards specifically referenced in this Standard, and sources from which these reference standards may be obtained.

1.5
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (nonmandatory) to define their application.