Flue sensor for gas fired appliance

摘要

A fuel fired appliance exhaust gas parameter sensor for continually detecting gas parameter emissions, such as CO, NOx and O₂, may be located above the appliance near the appliance exhaust outlet. The sensor may be located near or under a draft hood located near the exhaust outlet. The sensor remains relatively cool by draft air moving from outside the draft hood and into a chimney, the draft being hastened by the heated, rising chimney gases. A sensor bracket may be attached to the appliance and the sensor to appropriately position the sensor under the draft hood. Alternatively, the sensor may be located on a tube that continually samples combustion exhaust. The tube may be located outside of the draft hood perimeter to maintain a low sensor temperature, while multiple tube coils around the exhaust outlet may be used to further cool the sampled gas.