While I am remodeling my office, I decided to take the opportunity to access some plumbing in the wall and ceiling. I have a bathroom on my second floor, and it takes a long time to get hot water up there since the hot water heater is in the basement.
The old setup was run with 3/4″ copper pipe. This worked well and provided a minimal pressure drop. But, it took almost a minute to get hot water up to the bathroom upstairs. Oh, and it was uninsulated most of the way too.
The choice to replace it with 1/2″ PEX tubing was almost a no brainer once I ran some quick calculations. 1/2″ PEX would only create an additional 2 psi drop versus the 3/4″ copper. After having used it a while now, this isn’t even noticeable. Also, 1/2″ PEX holds less than half the volume of water compared to 3/4″ copper, so the time to get hot water up to the bathroom would be reduced by more than half.
So, it was just a matter of picking up the necessary parts and going to work. The parts were pretty simple. Just a couple copper to PEX fittings, the tubing itself, and some pipe insulation. All in all, it was less than $25 in parts.
After everything was replaced with the PEX the effects were pretty drastic. It used to take 50-55 seconds to get hot water upstairs. Now it takes 20-25s.
Another side benefit is that I can now set my water heater to a lower temperature because the PEX is loosing less heat than the copper did. It used to be set to 140F, and now it is set at 130F.
Overall I’m very happy with the change. So, watch your plumbing sizes when you’re doing plumbing work, especially on the longer plumbing runs.
For more info, see the forum thread.