DEW POINT CALCULATOR EXCEL DOWNLOAD DOWNLOAD

Example psychrometric charts are shown in the following figures:ĬLICK HERE to download a psychrometric chart in US Units.ĬLICK HERE to download a psychrometric chart in SI Units Calculating The Relative Humidity From Temperature Using the two temperatures and a psychrometric chart, the relative humidity can be found. These two temperatures, which are recorded simultaneously and under the same atmospheric conditions, are used to accurately determine the relative humidity as follows. Meanwhile, a second thermometer attached to the first remains stationary to measure the dry temperature. A sling psychrometer is operated by wetting the bulb of one thermometer, which is then spun through the air to measure the wet temperature. This tool allows the user to find both the dry temperature and dew point temperature at the same location and the same time. This temperature is the dew point, which is the temperature at which water vapor begins to condense.Ī tool for accurately measuring the two temperatures is a sling psychrometer. To calculate the relative humidity, there are two factors that are needed: the dry bulb temperature T D, which is the temperature measured by a thermometer exposed to dry air, and the wet bulb temperature T W, which is the temperature measured by a thermometer whose bulb is covered by wet cloth and exposed to air. Things like structural degradation due to exposure to high levels of water in the form of vapor need to be considered, so knowing the expected humidity levels for a region is necessary. Relative humidity plays a role in defining an environment, and areas with higher relative humidity will have different requirements than those with lower relative humidity. In engineering, understanding the environment to which a structure will be exposed is often key. This is because the warmer air has a higher theoretical total humidity, so the ratio of the actual humidity to the theoretical will be lower, even if there is the same amount of water vapor in the air. Therefore, warmer air will have a lower relative humidity, and be drier. The relative humidity is inversely proportional to the theoretical humidity. When the air becomes saturated, it can no longer hold water as vapor, and the water in the air begins to condense out, becoming a liquid. Relative humidity refers to how much water vapor is actually in the air in relation to how much vapor that same air could theoretically hold without becoming saturated. Because humidity is a measure of the amount of water vapor in the air, and warmer air can hold more water vapor without becoming saturated, areas with higher temperatures will have a different total humidity than areas with lower temperatures. The relative humidity is the ratio that is dependent on temperature. Calculating Relative Humidity From Specific Humidity.Calculating The Relative Humidity From Temperature.

Dew point calculator excel download