People in developed countries spend the majority of their time indoors. Therefore, studying the effect of outdoor air quality on indoor air is of great importance to human health. This book presents several computer models that can be used to study this effect, analysis methods using these models, as well as measurement techniques and control strategies. Use of these tools is demonstrated using buildings in Fairbanks, Alaska, and pollutants of concern in this area - carbon monoxide, fine particulate matter, and radon. The results are presented together with the summary of findings by others in different geographic regions. The core of this book is four peer-reviewed articles that were accepted for publication in various journals, plus supplemental material. This compilation of the work of these authors into a cohesive package represents suitable reading for students, researchers, housing specialists, and other individuals who want to learn about the effect of outdoor air quality on indoor air, about methods to study this effect, and about possibilities to enhance indoor air quality via reducing the indoor levels of pollutants of outdoor origin.