Core TradesQuestion 146 of 700
Taking return air for a residential forced-air furnace from a garage is prohibited primarily to prevent:
a.Drawing carbon monoxide and fuel vapors into occupied living spaces
b.Excess static pressure in the ducts
c.Condensation on the coil
d.Loss of airflow at the registers
Explanation
A garage can contain vehicle exhaust and flammable fuel vapors; if the return draws from it, those contaminants are distributed throughout the house, creating a poisoning and fire hazard. The prohibition is a health-and-safety rule, not about static pressure, condensation, or register airflow.
Law Reference: 2025 CA Mechanical Code §918.0Practice all 700 questions free — no signup required.
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