To keep our indoor environments as healthy as possible it is important to control the amount of moisture in the air. When the air is dry, we can feel it. Our eyes feel gritty, our skin becomes rough and flaky, and we seem to get sick more often. The goal is to keep the relative humidity level in buildings between 40 and 60% RH. This will not only reduce the amount of viruses and bacteria in the air, but also inhibits the development of mold or fungus.