LCS Laboratory offers measurement of Relative Humidity (RH) as a part of our Indoor Air Quality (IAQ) service. RH is a measure of water concentration in the air. For example, 5-15% RH would be a typical humidity of Death Valley, California. On the opposite end of the spectrum, would be humid air on a rainy day with an RH of 90-100%.
A comfortable range of RH depends on your acclimatization (which changes with the season) and air temperature. For most people, optimal humidity levels are between 40% and 50%. Health Canada recommends 30% RH as the lower acceptable limit for winter or summer (Health Canada. Exposure Guidelines for Residential Indoor Air Quality. 1987, ISBN: 0-662-17882-3). The upper limit is 55% in winter and can be as high as 80% during summer.
Very dry air with humidity below 25% can be harmful, for example, our skin can get dry and may require more attention. Dry air can cause respiratory ailments such as asthma, bronchitis, sinusitis, and nosebleeds, as well as general dehydration since body fluids are depleted during respiration. Irritating effects, such as static electricity, which causes mild shocks when metal is touched, are common when the air moisture is low.
High Relative Humidity in combination with elevated temperature may first cause discomfort, and if not controlled properly may lead to heat exhaustion and eventually heat stroke. In addition, some microorganisms thrive in humid environments. When humidity rises above 55-60% mold starts to grow.
The effect of relative humidity can be better understood in connection with other parameters, that are tested as part of our extensive Indoor Air Quality screening. To learn more about this service, please visit the IAQ webpage
