Happy New Year!

5 January 2018

This past month has been full of family and holiday cheer. But not so full that we didn't have time to work on the house. Although this past weeks' frigid temps have slowed us down a bit.

The ProPEX pipe and fittings arrived.  UPS delivered 11 separate packages.


I have two goals for the water supply system. The first goal is to make the water flow at each fixture as evenly as possible. Traditional plumbing uses a trunk and branch design. I'm sure many of  you have felt the effects of this when taking a shower and someone else flushes a toilet. A sudden draw of water upstream of where you're using it can cause the pressure or flow rate to drop.


From what I've read and seen, using a manifold distribution system is the best way to achieve even water flow. Here is an example of a home run plumbing system with a central manifold and a separate 1/2" water pipe going to each fixture. In theory each fixture gets a relatively even flow of hot and cold water.


I opted not to do this for two reasons. First, like the photo above, we were looking at around 20 cold line runs and 12 hot line runs emanating out from the mechanical room. We still have electric and HVAC to do, so I decided that 30+ water pipes running under the house was too much.

My second goal is to minimize the amount of time and water wasted while waiting for hot water at any of the sinks which brings me to the second reason not to do a home run design. The home run system works best when the manifold and hot water source can be centrally located to all the plumbing fixtures. In our case, we can't do that. The mechanical room is adjacent to one of the bathrooms, but approximately 80' from the kitchen/laundry and 60' from the master bathroom. Barring a central manifold location with short pipe runs, I decided that the best way to reduce hot water wait times in our case is to use recirculating pumps. But doing that with individual pipes for every fixture is not practical.

I decided to do a hybrid manifold water system in the house. There will be primary zone manifolds in the mechanical room. Then at each zone (we will have 4) there will be smaller manifolds where the water will be distributed to each individual fixture in that zone. We will be able to recirculate the hot water from each zone manifold keeping the hot water wait times down to 5 to 10 seconds no matter where you are in the house. That's my plan anyway.

I started each run from the mechanical room. Here are the 3/4" hot and cold supply pipes that go to each zone. The white pipe is a 1/2" return line that will be used to recirculate hot water from the kitchen zone.


Here are the hot and cold supply pipes for the kitchen zone. The blue pipe in the background to the left is the main water supply that goes to the mechanical room.


At the end of each zone pipe run, we installed these six outlet manifolds. I wanted to have at least one spare outlet at each manifold so I ordered these, as the next size down only had four outlets.


Amy and I installed all the pipe for the four zones and all the fixtures. In places where you won't see the pipes come out of the wall, like behind a bathroom vanity, we stubbed out with the Pex.


In places where you will see the pipes, we stubbed out with copper.


Then I started working on the primary manifolds that will be in the mechanical room. I made the manifolds from 3/4" copper pipe and designed them in a continuous loop layout because I had seen this on a YouTube video. Intuitively it made sense to me that it will do the best job of balancing the water flow to each zone. I couldn't find anybody selling manifolds like this pre-made, so fabricating them myself was the best option.


I built supports to organize the pipes coming in to the mechanical room.


Then attached the manifolds. One each for hot and cold, and one on the supply side to split hot and cold. I left room around the incoming main supply pipe to add filters or a shut off valve later if we decide to add them. At the moment the main water shut off valve will be located just inside the crawlspace door.


I decided not to put any valves here. Instead there will be shut off valves at each fixture like sinks and toilets. We will also put in-line shut off valves for showers/tubs and hose spigots near each of those fixtures. The ProPex is so easy to work with we can always add valves later if the need arises.


This system will need to hold 100 psi of air pressure steady to pass rough in inspection. So far we've had to redo three of my copper assemblies due to my rusty soldering skills.

Amy took our knowledge gained from the window workshop and started rehabbing one of our sashes.


The next big step is electrical. Woot woot! Oh, and we're probably going to put back a wall between the living room and dining room that was removed by a previous owner.


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