There are dozens of subjects one could study in this life, and it would seem that the old adage is true - "The more you know, the more there is to know." I remember clearly having absolutely no appreciation for how air moved through fans, ducts, or houses, thinking that it just happened. About 30 years ago I was asked to use the waste heat from the transmitters of a radio station to heat some offices, and that opened the door to the wonderful world of mechanical ventilation. I had to figure out how to move that air, what sort of fans to use, and how the air would move through the building.

To solve that problem I met a fan salesman named Jack "The Boze" Kennedy, who taught me about axial fans and venturis and the fact that fans can "suck" and "blow" and a bunch of other salesman stuff that is not the subject of this book. He also introduced me to a modular home company through which connection I met my wife, Kate.

Clearly a "house is a system." It is a working shelter for its occupants. That is its purpose - its reason for existence. People need to be warm, dry, and comfortable. And we need air to breathe. We can't just keep breathing the same air over and over any more than we can keep eating the same food over and over. This book is about ventilation for homes, both new homes and existing homes, and how to get the air to go where you want it to go and do what you need it to do. Remember that air doesn't always follow the arrows on the diagrams.