Normal snow line ???
 

The venting instructions for my furnace reference a term.. "normal snow line". Anybody know how high that is for Cumberland / North Attleboro area??

Depends on th ehouse. I have one spot facing NW that has snow half way up the door routinely and the exact opposite end of the house sometimes has bare ground at the foundation after a 2 foot storm, so you really need to consider where you put the vent or you could sleep right through your own death.

Just the term "normal" tells me its some kind of estimate or code number for an area. Some years we get 6 inches of build up and in years like 78 or this past winter probably 6 to 8 times that on average and in exact spots , who knows. There are other references that say "normal snow line or 12 inches above grade". If I come straight out just above the foundation I have the 12 inches covered but if I need to go much higher I'll have to put in a "periscope" extension thingy. The vent for the cloths dryer has been just on top of the foundation for over 40 years and no issues. However that is a simple exhaust vent and its warm/hot air. the vent for the new furnace is a concentric pipe with both intake and output in it and I get the impression the outflow is not at all hot.