WNA, Inc.

For a closer look, click on the photo below (bottom left) to see the Summer 2007 installation blooper.

The possible responses are listed below, with the correct reponse in bold.

	The increased duct surface area acts as a heat exchanger and helps boost the "free cooling" in the winter and "free heating" in the summer.
	The ductwork leaks and supports itself by its own air cushion, similar to a hovercraft.
	The ductwork protects the roof underneath, making maintenance of the roof membrane unnecessary.
	The top surface of the ductwork provides a convenient platform for access to the roof top unit.
	Proper service clearances are essential to maintain HVAC system equipment performance and reliability. In addition, a minimum of 24 inches of clear space should be provided under all roof mounted system components to allow for roofing maintenance and replacement.

WINNER

Congratulations to Laura Yamaguchi, CE, Principal of Azure Engineering in Oakland Jose, California. She correctly identified the Summer installation blooper and will enjoy a $50 Visa gift card.

Enter this month�s contest at www.wnainc.com/contest.html and you could be our next winner! Drawing will be held December 21.