I didn't post about the logstore and I understand it was a just a suggestion. Bear in mind, the fellow who gave you that tip helps a bunch of other people, too. It isn't uncommon to lose track of where someone's individual project is at the moment. Just the nature of any internet forum
The solar "requirement" isn't really a requirement then? If necessary, you simply at a panel or two as you resize your yet-to-be-installed solar system. Well that makes it easier! Grid-tie and you can still weight it towards battery/off-grid, based upon your battery size, solar hours per day, worst-day solar and reserve capacity, etc. If you're working for/with a solar company, surely you/he has all this capability of calculating anyways.
That being said, and trying to take all your requests into consideration, perhaps you will gain some traction asking about Gravity Flow Systems (mostly) with a pump assist.
Treat the remote boiler separately. You MUST do this in my opinion, regardless.
Any good heating system (lets stick with hydronics for this discussion) is made up of 4 parts.
1. Heat Plant. Your boiler must be able to provide enough BTUs, using a reliable fuel conversion method to a Primary Loop (open or closed)
2. Distribution System. This is your secondary piping, zones, loops, pumps, whatever you decide to install. Each has its own benefits and cons, including costs to install, operate, etc.
3. Controls. Zone controls, valve operations, logic, thermostats, heat plant controls, etc
4. Resources. Electrical, physical paths or restrictions, distances, fuel storage, man-in-the-loop considerations (ie fill hopper, empty ashes, shovel coal), etc
These parts are all independent, yet the interconnection of them will affect the other parts and requirements.
In designing a system, here's a suggested method.
1. Decide on general heat plant. What type of fuel, delivery method (steam, water, air), SIZE, location, draft, all that good stuff.
2. Your distribution system is independent from the heat plant, but is constrained by the choices made for the heat plant. What kind of piping (PEX, copper, steel), where (basement and then up, or home-runs, room to room) , how to run it (split tee, reverse returns, etc), SIZE, how to cause flow and return, and DESIGN TEMPERATURE/FLOW RATE per zone/loop.
3. Are you going to use electronic controls like Taco Zone controllers connected to thermostats, or TRVs, or something else? Although independent, they must interface with the heat plant and distribution system. Don't forget safety controls.
4. How much space do you need, electrical requirements, makeup water (do you have WATER in the garage?), chimney/vent/combustion air, where to store fuel, how to keep fuel supplied to heat plant, do you have people to handle the fuel/ashes or need something more automatic, etc
When one of these factors change, it can impact the others.
1. I like to start with a rough idea of the distribution system.
a. Hot water, steam, or air. You said water
b. Type of radiant. You said radiators
c. Zoned? How many? Requirements of each? You have some of this
d. How will you plumb it?
1) You want 11 separate zones, using reverse returns, considering split tee if needed, using mainly PEX.
2) You also want to use a manifold(s), possibly split into two because of stone wall separation of the house.
2. Heat Plant
a. Coal boiler located in a remote garage, connected to house with insulated underground pipe.
b. If using a primary/secondary loop configuration, "normal" circulators can be used (constraint for distribution system)
c. Freeze protection and insulation resources triggered by remote garage and underground (if you have a failure or have to shut down the system during cold weather). Do you have a secondary heat source in the garage to protect the boiler? Consider antifreeze treated primary loop due to underground?
d. You already have a coal boiler, right? That is a constraint for your distribution system. Good zoning can help stagger a load, which can "help" an overloaded boiler- if that is the case.
a. You said you want TRVs and a constant circulation system.
b. Not sure of best way to control zoning and constant circulation
c. Simple aquastat at the boiler?
d. How will it adjust for changing flow rates as zones switch on and off?
a. Electrical desired to be as low as possible
b. Insulation of house is very low- MAJOR impact on all other parts to achieve any reasonable degree of comfort
c. Remote Heat Plant has losses that need to be factored in.
d. No ECM circulators. I listed this here as it affects all other parts
e. No individual circulators per zone. Also here because it constrains other parts
As each of these items (and others) are "filled in" they must be checked against all the other parts. Some will have little or no effect, others can create "must have" or "can't have" conditions in the other areas.
So for now, why not concentrate on JUST the distribution system. Figure out how you propose to do that, constrained by one or two pumps, using manifolds, piping that will work in your house, using x number of zones, using cast iron radiators, and minimize electrical usage.
Once you work that out, you can worry about the Boiler and Primary Loop and any factors that a remote install bring to the party.
Why don't you want ECM circulators again? Is it cost or something else?
What is the heat load per zone and for the house? Now, short term, later, is fine and how I did mine. It also got me hustling on insulating key areas, LOL.
Also suggest you consider which is more important- low electricity usage, 100% solar capability, installation cost, fuel usage efficiency, steady comfort temp, physical requirements (some people want radiators, some want baseboard, certain piping, etc), or something else?
Any system is a balance of requirements. Scattershot is a good way to get started and get rough ideas and uncover options, but then you must start narrowing down and choosing or ruling out certain items.
If you absolutely NEED full upfront details and examples, then I'd just say copy my design...or Rob's design...or Larry's design...or...LOL. I say that in jest, but in all seriousness if you find one you like, design yours like that to begin and adjust the design from there. At least you'll have a base to start.
One last point for this very LONG post.
There are lots of cookie-cutter solutions out there. Installers use them all the time. You can use them if you want. But most of the time they aren't the most efficient system, sometimes not even "acceptable" by the standards of many here. But they are FAST, and SIMPLE to use and follow. Call up "Joe the Plumber" and tell him to come put in a system and he'll do it.
But it seems you are interested in a more customized solution that you can do on your own? I think mostly all of us on this forum are in that boat. Sure, the degree of how "involved" we want to get may vary (especially with some of your REALLY OLD fellas, haha!), but we're here to learn, solve, and share. If that describes you, then have at it!
Ain't everybody's bag o' tea.