hydronic heat for the barn - part 2

 

One thing that I learnt very quickly since moving out into the country is what I used to take for granted of able to go buy anything with ease when the needs arise is a distance experience. A round trip to the closest well stocked stores takes 3 hours drive, plus the time shopping. Most often the things I need can only be procured by special order, or a 6 hours round trip driving into the cities. I am now forced to be more precise and planning ahead. Well compiled shopping lists are essential, and patience pays in avoiding unnecessary waste and inflated costs.

Installations of the mini split heat pump and the hydronic in floor heat are special tradesman territories and most DIYs often will waste a lot of money to finally getting it right. I try to avoid such pitfalls in practicing iterative design and planning refinements. Giving myself ample time to reflect and refine my initial design before making monetary investment is key in controlling cost and waste. I considering each trip of my time and fuel as investment and do not take them lightly.

Unlike living in the city there are risk of freezing of the hydronic system this time I will have antifreeze in the radiant loops. A system feeder will be required.

this is one system feeder that I would choose for $500

A system feeder that I initially chosen is one made by Axiom for $500. However as soon as I looked into it, I said to myself I can fabricate my own system for a fraction of $500 price tag. I set out to design it out.

I rounded up some hydronic parts I have left over from previous house

the installation requires a lot of expensive copper and brass plumbing parts so careful checking of dimensions is necessary for the schematic design and compilation of an accurate parts list

The boiler's water inlet and outlet are 1 1/4" ID. Home Depot no longer stock any copper or brass plumbing parts over 3/4". A few Lowes stock 1" and 1 1/4" but generally very poorly stocked. Hence even taking a long trip into the city to try getting all the needed parts is a fool's errant.

my marked up schematic

Before putting up the 4x8 feet sheets of plywood to support the hydronic system installation I needed to protect the utilities that run on the girts from being punctured by the sell-drilling wood to steel screws. the refrigerant lines for the mini split system and the propane gas lines are the most vulnerable. I cut some spacer strips of the Corning XPS foam board to place along the girts to protect them.

I almost bought a foam cutting hot knife but decided that I can save the money

putting in place requires pulling up the vapor barrier again but at least I know for this bay it would be the last time I need to do this

I ordered these silicone gasket from China via Aliexpress

my well planned trip to Home Depot to pick up just enough plywood and the other misc parts; this is the first time the truck hauls sheet goods with the tonneau cover installed

The most crucial plumbing parts would arrive today from online order.  I picked up a 10' 1 1/4" L copper pipe from Lowe's in last grocery trip into the city.

I chose 3/4" T&G subfloor plywood as they interlock nicely; there is no vertical member on the steel building and the only support are horizontal that are 7" 6" apart

I was planning on adding vertical stringers on the outside surface to support the circa 160 lb wet weight of the boiler plus the plumbing and utilities but so far the R30 insulation behind helps stiffen them nicely

I managed to raise and mount the 130 lb boiler without help

From early on I designed all the surface part of the hydronic heat to fit onto two pieces of 4x8 feet plywood. I want the boiler to be on one plywood without straddling the seam. I also want to minimize the plumbing and other component cost. The pex pipes existing from the slab primarily dictates the location of the boiler, and the boiler in turn everything else. The copper plumbing takes precedence over the PVC combustion air inlet and outlet. Next comes the system fill, and then the propane supply. Last is the electrical and the thermostat.

I want to spend the least money but result in the best performance so I am cheaping out on where I can save cost, including the thermostat which I would reuse an old one that was not designed for hydronic heat if I can get away with it. I like working with what I have.

I needed to revise the propane plumbing now I chosen the location for the boiler; the 2x4 blocks are my helping hands in pushing the plywood back to make room for working on the iron piping

Until I receive my first batch of copper and brass plumbing parts I only move ahead on the utilities that I know I would not need to relocate so I proceed cautiously with patience.

the chosen boiler location comprehends all the system components including the combustion intake and exhaust; the most critical constraints are the hydronic plumbing

I planned for a 4-plex outlet with a MC pigtail supply to the anticipated secondary loop pump

I long provisioned a dedicated 20A service for the hydronic heat system. Per code every branch must be protected by a GFCI. I normally would install a switch for the outlets but since I want four outlets the GFCI will serve that purpose. Also the breaker for this circuit is easy enough to get to.

I decided not to cut the MC cable and finish the 4-plex in case I need to relocate the metal box

the first sets of hydronic plumbing parts will arrive today and I would be able to conduct more accurate physically placement of them and the pipes

While conducting some dimensional checks I already identified some issues and came up with least cost  and time changes. Since I want free shipping from the online vendor I had the foresight to withhold ordering of the circulation pump so I can make the minimum order for free shipping once I am able to identify all the remaining plumbing parts which will be less than the threshold. 

 I also rounded up my stash of copper plumbing leftovers which contain no less the $80 of usable 1" and 1 1/4" copper