I have a four bedroom ranch home about 50 years old. My question: am I saving money by closing the air vents in 3 of the bedrooms, living room and dining to save on A.C. costs? I have French doors between the living / dining room and den / kitchen, so closing off rooms is very easy. 95% percent of my time is spent in the den, kitchen and one bedroom. The main return air duct is in the hallway. Am I saving money by closing off as many rooms as possible or better to leave one or two more rooms open? Appreciate your thoughts !!

If you have the kind of AC that has a variable fan speed and can regulate down so closing off air flow causes no damage, then yes; but be sure you have that first.

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