Unfortunately, many have either witnessed or been directly affected by this phenomenon, which has become known as the "sick building syndrome". We have learned that it is expensive to repair damage caused by unwanted moisture, and doing so wastes an incredible amount of energy. Also, and most importantly, living and working conditions are eroded and severe health problems may be caused by chemical and biological contaminants from volatile organic compounds, respirable particulate matter, bacteria, molds, and pollen that can form as a result of such damage.