The ATMOX goal on fan placement is to create a total ventilation solution for the crawlspace. It is very important to have an equal air exchange in the entire crawlspace. Leaving one area without proper airflow can still create undesirable consequences to the crawlspace in that area.  

All fans are assembled in the USA. The fans are designed to be whisper quiet so that you will not be able to hear them in your home. (This is a real differentiator from other fans on the market.)