Any point in 1" supply if water heater is 3/4"?

[rgeorgejr]

I'm plumbing my own new house and would like to have plenty of water pressure. I plan to use 1" copper after it enters the house and then convert to 3/4" after the manifold to each zone. I'm going to use a Marathon water heater which has the common 3/4" adapters. My question: Is there any point in using the 1" pipe up to the manifold if the hot water has to go through the 3/4" fitting on the water heater anyway?

 

[Another-Plumber]

pressure and Volume are two different things, no house i have ever seen had 1 inch to the water heater unless you have 10 bathrooms to speak of

 

[LiQuId]

as has been stated repeatedly, Size of the pipe and pressure are not variables of each other.

1" is used on occasion to feed 3/4 branches inside a house on the cold side since there are more cold fixtures than hot. if you used 1" piping after the HWT you would be just wasting money.