For rooms up to 75 sq ft, go with a fan 29–36 inches. Rooms 76–144 sq ft work best with 36–42 inches. For 144–225 sq ft, choose 44–50 inches. Larger rooms (225+ sq ft) need a 52-inch fan or larger—or consider multiple fans for great rooms and open floor plans.

In most cases, yes—but the electrical box must be fan-rated. Standard light fixture boxes aren't designed to support the weight and vibration of a ceiling fan. If your existing box isn't fan-rated, an electrician can swap it out, which is a relatively quick job.

Yes. Running a ceiling fan costs roughly 1–2 cents per hour compared to 10–15 cents for air conditioning. Fans don't lower room temperature, but the wind-chill effect lets you set your thermostat 4–6°F higher in summer while feeling just as comfortable. In winter, reversing the fan direction (clockwise on low) pushes warm air down from the ceiling.

DC motor fans are quieter, more energy-efficient (using up to 70% less power), and typically offer more speed settings. AC motor fans are the traditional standard—they're less expensive upfront and have a long track record of reliability. For bedrooms or living spaces where noise matters, DC is worth the premium. For utility spaces, AC does the job.