The Hevacomp Wiki pages include a variety of Hevacomp related help topics, from calculating the angle to South to adding in more complex roof constructions.
You can find the Wiki here: http://communities.bentley.com/search/SearchResults.aspx?q=hevacomp%20AND%20app:wiki&o=Relevance
Thanks Huey, this link will bring you to the Wiki:
communities.bentley.com/.../default.aspx