Flame Roll-Out Study for Gas Fired Water Heaters

摘要

Five gas-fired water heaters were tested in laboratory with simulated home conditions to evaluate their flame roll-out characteristics. Simulated variables were flue blockage, space pressure depression, access door status and other related factors. Test results were compared with those based on the proposed American National Standards Institute (ANSI) test method. The testing concludes that, in addition to flue blockage, pressure depression and door status are major factors in inducing heater flame roll-out; that poor draft hood performance contributes to the likelihood of flame roll-out; that the proposed ANSI test method should add a temperature criterion for determining flame roll-out; that the proposed ANSI blocked flue test appears to be adequate for units equipped with thermal spill switches located at their access doors area. Recommendations are made that the Consumer Product Safety Commission (CPSC) and the ANSI sub-committee on water heaters consider also requiring the interlocking of access doors with water heater operation, the use of temperature sensing as a means of detecting flame roll-out, and the use of improved draft hood designs and draft hood performance testing to reduce the chances of flame roll-out.