I live (own) in a condo and the tenants above me are smokers and their cigarette smoke is encroaching in my living space. I contacted the landlord and HOA numerous times and nothing has been done to date. A friend of mine suggested installing an air booster to bring fresh air in. There are two pipes going up my ceiling in my utility room and we tested both pipes and came to the conclusion that the air is being pulled from the attic. The air was not cold even though the outside temperature was very cold. The room smelled like stale cigarette and fabric softener with the fan on whereas the odor was faint or not not when fan was not running. The question is, is this built in accordance with Denver Building Codes??
These sound like combustion air ducts for a gas heating appliance. Combustion air from an attic is completely in compliance with any US code in the last several decades. It is dangerous to obstruct these ducts in any manner. Doing so can severely compromise the proper combustion and venting of heating appliances, possibly leading to carbon monoxide (a colorless, odorless, tasteless, toxic gas) entering into your dwelling.