Pex Design Question

[Rocknroj]

I am replacing my system with wirsbo. I have an open jolst bay that services 2 showers, laundry, and 1 lav. It is located about 12 feet from the water heater. I am planning on using a manifold with 1" inlet and 1/2 lines through the joist bay for each cold supply. From the manifold, the trunk line continues another 5 feet to another joist bay serving 2 toilets, 1 lav, 1 hose bib. Here I would place another manifold for the cold. I was going to do same for hot, except without the second manifold (not needed). In researching, it seems it may be better to place a manifold closer to the hot water heater and run the 1/2 lines the extra 12 feet rather than fill the 1" line each time I need hot water. Perhaps I answered my own question and am looking for some experienced confirmation.

So my question restated.. Should I make long runs of 1/2 for the hot or run them off a manifold closer to their destination? It seems that this would give me quicker hot water when first used.

Thanks in advance..

 

[NHmaster]

I doubt you will notice much difference, but smaller lines will get the water there faster.