Second floor supply loop routing... Help solve brotherly quarrel.

[whackit]

Okay, Multi part story here. But I'll give you the gist of it. I am helping my brother replumb his house. We are using copper because we like it better than pex and the labor is free... The supply is designed around a 3/4 hot water loop. I can either locate it so the trunk runs through the attic (So Cal house) or bore through the second floor joists and locate it there. The through the attic route is easier, the through the joists is more labor but not bad since the house is open and would result in a shorter loop. We have discussed the pros and cons of both. What we are really want is opinions to help end a brotherly quarrel. Remember that we are more concerned with quality rather than speed or cost.

 

[hj]

There is no functional preference to either way, and the attic route should be easier.

 

[Sponsor]

 

[whackit]

There is no functional preference to either way, and the attic route should be easier.

Understood. But (you'll get what side I am on) wouldn't you say that reducing the hot water loop by 16' is significant in long term radiant losses? As well as keeping the pipes within conditioned space?

 

[Terry]

I don't like running pipes in attics. I like installing below the floor.
And I see nothing wrong with using PEX on a repipe. There is a lot less patching with PEX, and less chance of torching the home.

 

[hj]

16' is so insignificant that it is not a factor. I would say that in almost, (if not all), every house in this area, with PEX piping, it is in the attic. But if you want to go to the work of drilling through every joist for it, go for it.

 

[hj]

Out inspectors do not like soft copper above the floor, and if yours are like ours, then you are going to be using a lot of short pieces and couplings.

 

[Jadnashua]

16' of 3/4" pipe will hold about 1.5qts...not really enough to be a major issue. But, if it isn't run underneath the insulation and next to the ceiling, it has the potential to freeze on those rare occasions in SoCal. The other issue is, that it could become super heated, verses chilled in the a/c conditioned space.

When I lived in Kuwait, our water tank was on the roof, and during most of the year, it became so hot, it would scald you so we shut off our WH, and used that as a storage tank that, normally, would be room temp, and the cold supply as the hot.