Get Help from Bob Vila
- Give-Aways & Offers
- Monthly Must Do's
- DIY Project Ideas
- Step-by-Step Guides
- Inspirational Photo Galleries
jimrox is correct. The attic fan is necessary. It draws the hot air from the top of the attic out, which draws cooler, outdoor air from the outside in. You also need to ventilate the attic so that mold and other undesireables do not grow in it.
Moreover, if you do not vent the attic, then the insulation will never air out, keeping the smell in your home instead of dispelling it.