Which of the following decreases the risk of condensation?

Insulation effectively decreases the risk of condensation by maintaining a consistent temperature within a building, especially in areas where warm, moist air can come into contact with cooler surfaces. When walls, attics, or ceilings are adequately insulated, surfaces remain warmer, which reduces the likelihood that moisture in the air will condense into water droplets. This is particularly important in climates with high humidity or during colder months when temperatures fluctuate.

While all the other options may play a role in managing moisture levels and temperature within a space, they do not address the root cause of condensation as directly as insulation does. Heating typically raises the indoor temperature but can lead to higher humidity levels if not managed carefully. Cool air circulation helps maintain air movement but does not prevent surfaces from getting cold enough to cause condensation. Dehumidifiers lower humidity levels in the air but do not inherently keep surfaces warm; their effectiveness can be limited if the surfaces themselves are not insulated properly from the cold. Insulation, therefore, serves as a critical barrier that helps prevent condensation by ensuring that warm air does not cool to the point of dropping its moisture content.