Gas & Fuel第 71 / 110 题
Using the known-air-infiltration method, an appliance space of 10,000 ft^3 is credited with 0.35 air changes per hour of natural infiltration. How many cubic feet of infiltration air per hour does the space provide?
a.350 cfh
b.1,750 cfh
c.3,500 cfh
d.35,000 cfh
解析
Infiltration air = volume x air changes per hour = 10,000 x 0.35 = 3,500 cubic feet per hour. This method credits only the air that leaks through a standard building, which in a tight modern house is often too little for the appliance load. When it is insufficient, dedicated outdoor combustion air must be supplied.
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