Kit sink, Prep Sink, DW on 2 PEX Hot Water - which ones grouped?

[Rossn]

I have a kitchen that I am plumbing for hot water (cold is handled differently) using 1/2" PEX-A/Expansion (about 15' from manifold), and have:
- Kitchen Sink
- Prep Sink
- Dishwasher

Which options are acceptable?

Opt. 1: All 3 on a single 1/2" PEX-A for Hot Water
Opt. 2: Kitchen Sink and Prep sink on (1) 1/2" PEX-A and DW on second 1/2" PEX-A (this setup would keep hot water to the sinks with little cool-down
Opt 3: Kitchen Sink and DW on (1) 1/2" PEX-A and Prep Sink on a 3/8" PEX-A
Opt 4: (least preferred for hot water management): Kitchen Sink and DW on (1) 1/2" PEX-A and Prep Sink on a 1/2" PEX-A

Many thanks!

 

[Rossn]

I think I answered my question based on Uponor's PDAM charts, but practical confirmation would be good. It looks like pressure drop and flow are find for any two of these devices combined, but not 3.

To speed hot water delivery, would anyone ever run 1/2" the first 8', then tee off two 3/8" lines to run the 6' to the kitchen sink and 3' to the prep sink? DW would be on its own line.

Based on 2.2 GPM kitchen faucets at 80% HW, 3/8" should be fine on a short run, but it might be unconventional to do so?