Hey Marc, not sure if you are still active in this thread or not but thought I would share. There are a few companies that are extremely beneficial in their knowledge of sports field conditioning. From the field construction aspect, Sports Fields, Inc. aka “Fields” has done more heated sports field than anyone I know. Not only that, but their fields are awesome. They are the preferred contractor for the Green Bay Packers as well as many others. If you are looking for more information on sports field heating or cooling for natural grass or synthetic turf fields, try http://www.radiantso.com These guys have been cleverly hidden behind some of the best designed fields for heating and cooling. They have done some of the work for FIELDS and numerous other large, high profile radiant applications such as cooling for agricultural, grain, and rice. They offer both hydronic or electric systems and probably have the information that can help you out. Hope this helps.!!!!