Jadnashua
Retired Defense Industry Engineer xxx
In searching around BW's website, they have both direct vent and POWERED direct vent systems. Here's one of them http://www.bradfordwhite.com/images/shared/pdfs/manuals/238-47936-00C.pdf, and depending on the size of the piping you use, you could have up to 95' (when you use 4", it's 55' if you use 3" pvc) if you can get by with only one elbow...that should be enough for nearly any house.