CSA ANSI Z21.91:2017 pdf download.Ventless firebox enclosures for gas-fired unvented decorative room heaters
4.1.8 The construction of the firebox shall be substantial to the extent it will support without damage 300 Ibs (362.9 kg) of weight uniformly applied to the top of the firebox. Fireboxes designed for recessed installation only need not comply with this provision.
4.1.9 A freestanding firebox shall be designed so it cannot be tipped over as determined by the following Method of Test. This test does not apply to fireboxes that are provided with means (including necessary screws, bolts, or both) and instructions for attaching it to the floor or wall.
Method of Test
Fireboxes when tipped in any direction at a 15 degree (0.26 rad) angle from the vertical shall not tip over when released.
4.1.10 Parts of the firebox that are intended to be installed into combustible construction shall be suitable for 0 inch clearance to combustible construction. This may be accomplished by use of spacers provided as an integral part of the equipment by the manufacturer.
4.2.1 The manufacturer shall supply evidence acceptable to the testing agency that all materials have been evaluated and found to be acceptable for their intended usage. Test data based on ASTM or other appropriate test procedures, certification, or historical data may be submitted for this purpose. The evidence shall show that the materials have been evaluated, as appropriate, for resistance to moisture,corrosion, temperature, the effects of fuel gases, and any other compounds or conditions to which the materials may be exposed. Nonmetallic sealing materials shall also be suitably resistant to the effects of ozone.
4.2.2 Materials used in the construction of those portions of the firebox that are likely to be exposed to the products of combustion shall be constructed of materials having the durability, and resistance to fire and heat equivalent to Series 300 or 400 stainless steel, aluminum-coated steel, cast iron, or 0.042 in (1.07 mm) thick unprotected or painted steel.
4.3.1 Electrical equipment and wiring, if provided, shall be listed or certified by a nationally recognized testing agency qualified to certify or list electrical equipment or wiring.
4.3.2 Under the conditions of the following Method of Test, electrical equipment and wiring shall be suitable for the temperatures to which they are exposed and the service to which they are subjected. Maximum allowable temperature rises of some typical wires and components are shown in Table 1, Maximum allowable rise above room temperature for various component parts.
Method of Test
The firebox shall be operated as specified in Clause 5.4, Wall, floor, and ceiling temperatures.Temperatures of electrical equipment, controls, and wiring shall be determined for each component at points subjected to maximum temperatures by means of thermocouples not larger than 24 AWG (0.20 mm2) placed in good thermal contact with the material. At the option of the manufacturer, the temperatures of motor windings and coils may be measured by the resistance method. Observed temperatures shall not be in excess of those for which wires or components are approved.CSA ANSI Z21.91 pdf download.