As summer months approach and Americans across the country are gearing up for warmer weather, humidity is also on the mind. In climates that experience hot, humid weather, humidity can make temperatures feel and behave as if they were several degrees higher. Additionally, too much humidity can have detrimental effects on allergy sufferers. As with most things, education and information are the first steps in arming yourself against a health threat. Here is a short list of terms and their meanings, simplified into laymen's terms.
Humidity - A general term that refers to moistness or dampness in the air. More specifically, it refers to the amount of water vapor in the air.
Relative Humidity - A ratio of the amount of water that's actually in the air compared to the greatest amount of water that could be in the air at the same temperature, usually expressed as a percentage. Put another way, it is the percentage of water in the mixture of water and air that composes the air.
Absolute Humidity - The amount of water in a particular volume of air, usually expressed as grams per cubic meter. It changes as pressure changes.
Specific Humidity - The ratio of water vapor to air in a particular volume.
Mixing Ratio - Also known as the humidity ratio, or colloquially as the moisture content, the mixing ratio is the ratio of the mass of water vapor in the air to the mass of dry air.
Dew Point - Simply put, the dew point is the temperature at which dew drops begin to form from water vapor. It is affected by pressure and water vapor content, which determine the temperature to which the air must be cooled in order for dew to form. The dew point is a saturation point, meaning that the air cannot receive any more water vapor. If the dew point temperature is below freezing, it is called the frost point.
Heat Index - A combination of air temperature and relative humidity, the heat index number is an attempt to express what the temperature feels like to a human, given a certain relative humidity. Since humidity makes the temperature feel hotter, this is valuable information.
Humidex - This is Canada's version of the American heat index. It differs from the heat index because it uses dew point rather than relative humidity to calculate the humidex number.
To accurately monitor the humidity in your home, we suggest the Acu-Rite Digital Humidity Guage. This simple, yet effective device allows you to keep a constant measure on the humidity to ensure your home remains healthy and comfortable.
In conjunction with a humidity guage, a dehumidifier is an effective solution to excess humidity in your home, crawlspace or other areas where environmental control is important. Dehumidifiers not only reduce the humidity levels but also help to keep temperatures cooler.