High humidity is generally regarded as the dew point temperature being at or only a few degrees below the measured air temperature. Dew point is the temperature at which water vapor condenses on surfaces, such as when morning dew condenses on grass.
People are most comfortable whenever the relative humidity level is around 45 percent says HowStuffWorks. A level of 100 percent humidity means that the air is saturated with water vapor and unable to hold more. When this happens, perspiration cannot evaporate into the air, making people feel hotter
Relative humidity is defined as the amount of atmospheric moisture present, divided by the amount of moisture that would be present if the air were completely saturated. This ratio is typically expressed as a percentage. Since the amount of moisture the atmosphere can hold is dependent on temperatur
Humidity in a home causes discomfort for occupants. If the levels are too high, the moisture encourages the growth of mold. Keeping humidity in the recommended 30 to 60 percent range requires a multi-step approach that includes venting, using HVAC systems and a dehumidifier.
Humidity can be measured by using a hygrometer. Types of hygrometers include the basic psychrometer, an electrical impedance hygrometer useful for remote locations, the condensation principle hygrometer and mechanical hygrometers.
Humidity levels inside a home should not exceed 30 percent in the winter or 55 percent in the summer, according to Home Energy Resource MN. The company provides a specific chart for different temperature levels.
Normal humidity within a home should typically stay between 35 and 45 percent, depending on local temperature and climate. Various methods exist that help to either bring it down or up as needed.
Higher temperatures make higher levels of humidity possible. This is because warm air is capable of holding more moisture than cold air. Warm air has a stronger bond to water molecules, making the air feel drier and allowing more water to bond with air.
Most homes should maintain a relative humidity below 50 percent at all times. This prevents mold and mildew growth, dust mite infestations, and condensation from building up in your home.
Any humidity of 30 percent or less is considered low and can be dangerous. Low humidity can cause breathing difficulties, discomfort and may damage a home's foundation.