eat, drink, men, women 飲食男女: hydronic heat for the barn

Sunday, January 22, 2023

hydronic heat for the barn - part 5

I was not looking forward to start doing the copper plumbing because of the need to route the pipes parallel to the back wall but at different planes for various system components. It is impossible to identify all the necessary fittings until you dive into it. Dive I did today even though I knew I need at least four more elbows. I also consider 45s instead of 90s for better flow.I also needed a 1 1/4" x 3/4" x 1 1/4" tee which I didn't identify and order, but thankfully I have my pile of used copper plumbing scraps and there is one in there. I needed to unsolder and clean to reuse. Without it I would be unable to make any progress as it is in the critical path of the supply side.

I rethinked the layout and decided that putting the pump on the supply side would save me a lot of work. It is the topology that the pump manufacturer recommends. I also reverted back to my earlier layout. With only six elbows I aimed to alignment the hot water supply down pipe to the corresponding manifold. That way when four more elbows arrives I only have to deal with aligning the cold return down pipe to the cold manifold. The supply side has the most ancillaries so I would make the most progressing.

To accomplish these I had to address routing the hot water supply pipes to accommodate the over-pressure valve, as well as the expansion tank which is daisy chained with the system feed. It was a tall order as I didn't plan and order those fittings. I had to rely on reusing old copper fittings from my scrap pile.

I reverted back to this original plan except changed the pump from the return to supply side; by putting the pump on the supply side I didn't need to move the manifolds outboard

the pump flange now is perfectly spaced from the back wall

a lot of soldering

The most difficult soldering were the joints at the heavy 1 1/4" brass valves as they have so much thermal mass. If your torch is under power you risk damaging the PTFE of the ball valve by burning it.

while dry fitting the most critical fittings I used masking tape to hold the fittings in place so I could carefully check the locations for the ancillaries, and the alignment of the supply down pipe (not yet install) to the plane of the supply manifold

once I finished checking I use this pipe to hold up the assembly and soldered the 10 joints in one go

one bad move could misalign all the fixings

the most difficult aspects of the plumbing is done; I even made the over-pressure discharge pipe

these few photos capture the intricate compound angles of the piping

the 1/2" port of the horizontal tee that shares with the over-pressure valve is for the expansion and system feeder

the expansion tank port is 5 1/2" from the wall

I was able to place the overpressure dischargee pipe close enough to the wall despite the test handle of the valve is angled in; I did this to reduce the plumbing complexity while accommodate the expansion tank connection that is 6.5" offset from the wall

With these done I wrapped up for the day. I re-compile the list of items that I need to procured:

1/2" 45 elbow, qty = 1

1/2" sweat ball valve, qty = 1

1 1/4" 90 elbow, qty = 4

Taco 1/25 hp IFC pump, qty = 1

hydronic thermostat with slab sensor, qty = 1

gallon size undiluted glycol, qty = 16

20A outlet with built-in switch, qty = 1

TBD supply hookup for the home made system feeder

I have a basic plan of the mount supports of plumbing. Most would be addressed with EMT conduit brackets with shim blocks. I might use Unistrut sparingly.

The diaphragm pump arrived. It is the lowest cost one powered by AC I found. I want one with low flow rate, low pressure, and with adjustable pressure switch. My goal is able to set it at 30 psi, but most of these pump are 50 PSI. They don't tell you how low the switch can be set to so the only way to find out is to buy one and test it.