Hi all.  We live in a typical two story, cookie cutter, planned community home in zone 4A.  The roof overhang is just the minimum drip edge and the entry door is fully exposed to the weather on the SE side of the house.  I know Martin advises that storm doors will never save enough energy to justify their purchase price and that on southern facing doors, the main door could get hot enough to damage door components.  I can’t help but wonder though, for homes that don’t have a portico, porch, or large roof overhang, would storm doors protect the entry door and jambs from water damage and make them a worthwhile water barrier?

If a storm door has an adjustable/retractable screen, would leaving the door in a partially vented mode keep the heat from building up any more than if there wasn’t a storm door?  I know I’ve seen the warranty language voiding the warranty for entry doors with storm doors on southern facades, but if I want to prevent water damage without an overhang, do I have a better choice? 

As long as we are considering heat build up from storm doors, are low E coatings on storm doors effective or is there no way to know their effectiveness if SHGC ratings aren’t available for a manufacturer’s storm doors?

Thanks.