Gas & Fuel第 62 / 110 题
Appliance venting is classified by category. A Category I appliance is best described as which of the following?
a.Positive vent pressure, non-condensing
b.Negative vent pressure, non-condensing (draft hood or fan-assisted, standard flue)
c.Positive vent pressure, condensing
d.Negative vent pressure, condensing
解析
A Category I appliance operates with a non-positive (negative) vent pressure and a non-condensing flue, so it uses a conventional type B vent or masonry chimney with natural or fan-assisted draft. Category IV is positive-pressure and condensing, requiring sealed plastic venting. Matching the vent material and pressure rating to the category is essential to avoid condensation damage or spillage.
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