On tankless hot water heaters and sizing a natural gas pipe

Researched tank-less hot water heaters and their voracious demand for natural gas. Decided to go for the Takagi T-K3-OS because: 1) it is for outdoor installation — no fancy exhaust flume required, and 2) its *minimum* BTU rating of 11K was one of the lowest I’d seen (considering that the maximum side was more than capable).

I [...]