50' of developed length. 232+ cubic ft per hr demand, 152 cubic ft per hr pipe (3/4" pipe with 256K btu's total demand)
pipe WAS o-k with tank water heater, now customer has gone to 199K tankless, and gone WAY over the max.
this wouldn't normally be an issue, except the 3/4" is buried under the garage slab for the first 20', and customer wants NO exposed pipe.
short of tearing up walls or slab, is there any way to have 3/4" for the first 20', then 1" for the remainder?
can that even be sized?