HJ, I'm referring to balancing the system, as BlackHawk mentioned a bathroom far down the line that sounded like it would have high demand - and I've already agreed that he should go ahead with his original plan that it will be fine... I'm not sure if my suggestion warrants an entire dismissal, which makes it seem as if drops in pressure within a household aren't an issue out there. I'm saying that if it were my house, and i had the opportunity to start from scratch, here's what i personally would do. oh right, what is it that i would do? lol... ok, here goes, sorry i don't have any diagrams for you:
I would most likely plan to have everything stemming from the same location, so i would bring the cold supply into the room where the water heater was going, and set up my header there - preferably in a central location in the house. I wouldn't branch off the cold to anything on my way there, except for the hot water tank.
- 3/4 cold supply directly into the mechanical room (or closet, basement, etc...)
- 3/4 hot supply from the heater
- basically the loops look like butterfly wings, but squared off, and one for hot, one for cold
- off one side of each "wing" are tees/ports for each fixture in the house
- the loop is closed on itself
- each loop is as big or as small as it needs to be, given the number of fixtures off of it. You can also add a couple extras and cap them off for future use.
What's been created is a loop that circulates when water is called for - as the demand for water increases, it's called from the same header at the same point that the others are. This reduces issue of a drop in pressure from one fixture (say the guest toilet) robbing the supply from another fixture that may already be in use (say the ensuite shower, which is further down the line). When we have branches off of a main supply, we create the opportunity for the pressure to be unbalanced. If they are all coming from the same source (the header) then the demand is being distributed to them more equally. More pipe is used, because you run individual hot and cold lines to each fixture from the headers. It ends up looking like a maze of nice, straight, tidy electrical lines clipped up there - except it's pipe. It is not necessary to have shutoffs for each port unless you want to be able to isolate each fixture for whatever reason in the future, but i've used the same system for multi-suite homes and then I definitely install shutoffs so you can isolate them from eachother easily.
I think that if "poppycock!" is hollered at this one, then I will just back way off and continue with my butterfly wings! I'm not forcing anyone else to do it, I just know that I have only had positive results from this practice when I've had the opportunity to implement it. As HJ said, go ahead with what you're doing, it's fine, it's how it's always been done, just run the 3/4 as far as you can.