In the process if doing an extensive remodel and I'm upgrading my natural gas plumbing. I've got the sizing all worked out but I'm confused about where sizes should change. My gas meter has a 3/4 inch output. I understand that I can connect my new 1 1/4 inch pipe as long as it is "close" to the meter. In other words there really is no need to replace the meter with one that has a 1 1/4 inch output.
I'm adding a 200,000 BTU tankless water heater that has a 3/4 inch gas inlet. So my question is where should I transition from 1 1/4 inch back down to 3/4? I'm mounting it high on the wall in a new laundry room so the gas line will exit about 5 feet up the wall. Should I run the 1 1/4 inch up that wall, or could I make the reduction in the crawl space before it turns up that 5 feet? I'm not too eager to cheap out and do whatever is easy, but I don't want to make it more complex of there is no value.
Pipe Sizing:
75' of 1 1/4 inch from meter to junction just below Water heater
5' of 1 /1/4 (?) from junction to 200k BTU Water Heater and 25k BTU gas dryer
25' of 3/4 inch from junction to 50k BTU cooktop
20' of 3/4 inch from junction to 50k(?) BTU gas logs
Thanks!