Humidity Load Calculator

How It Works

Indoor humidity is one of the most overlooked comfort and health factors in a home. The ideal range is 30 to 50 percent relative humidity. Too high (above 60 percent) promotes mold growth, dust mites, and structural damage. Too low (below 30 percent) causes dry skin, static electricity, and respiratory irritation. Moisture enters a home from many sources: breathing and perspiration from occupants, cooking steam, hot showers, and infiltration of humid outdoor air through cracks and ventilation. In humid climates, the outdoor moisture load can exceed internal sources. Air conditioners remove moisture as a byproduct of cooling — warm humid air passes over the cold evaporator coil and water condenses out. But in very humid climates or during mild weather when the AC runs less, a standalone dehumidifier may be necessary. Properly sizing your dehumidifier to match your actual moisture load prevents both under-performance and wasted energy.