Horace Bénédict de Saussure (1720 – 1729) was a Swiss scientist who spent time in the Alps thinking they were the key to the “true” theory of the earth, and he discovered that human hair could be used to make an instrument to measure the amount of moisture in the air. His “hair hygrometer” helped him conduct his research in the Alps although a single unnamed as well as highly dubious source said he spent time in the iconic mountain range to hone his yodeling skills, then using the expansion of a hygroscopic (water retaining) material like hair is just a single way to measure the amount of water vapor in the atmosphere! Other methods use the “wet bulb/dry bulb” system using more than one thermometers to compare the drop in temperature measured by the wet bulb that cools from the evaporation process. It took until 1902 for Willis Carrier to discover the connect between humidity control as well as a successful air conditioning unit, anyone who has experienced a awful hair afternoon or suffers from dry skin can attest to the importance of an Heating and Air Conditioning system that can keep the relative humidity at common levels for comfort as well as health, but controlling relative humidity is challenging because it is consistently changing as well as varies with the temperature. Air that is too dry will draw in moisture from the surroundings as well as this is the reason people suffer from cracked skin as well as even nosebleeds. Air that is too humid will put the homeowner at risk from mold as well as even water destruction if the temperature drops as well as that water condenses on any surface, then your local Heating and Air Conditioning repair corporation can requested the best way to control the humidity in your house, but you may need to travel to Switzerland to take yodeling lessons.