I am still reading and enjoying this site, and couldn't resist making another post. It is possible to get a seven day trial read of "Modern Hydronic Heating by John Siegenthaler", as a kindle e-book at Amazon. I have just finished up with my trial, and read a great deal of the book, and skimmed other parts. It is a great book, and I did get a good overview, but I must say, I didn't memorize all the equations. I have also ordered three books by Dan Hallahan, including "Pumping Away", His books are very highly recommended as being both informative, and as being very good reads. When I get that stuff all digested, I should have at least a pretty good picture of the scope of hydronic heating.
As previously stated, I had hoped to get a boiler room added to my shop this summer, and outfitted with boiler and heat storage. I still hope to do that, but am now thinking that I need to work on bulk wood storage first. I have burned wood almost forever, but have gradually gotten lax with proper storage and seasoning. Part of the reason for that is to cut down on the number of times I have to handle the wood. I am wanting to do something that would hold about three years wood supply as three separate areas which could be loaded out with a loader, and delivered to the boiler supply. I am still mulling that over.
Even if I didn't do the boiler thing at all, the good wood storage and dry wood would be a boon to my present multiple stove heating setup.
I have enough math skills to do almost any amount of number crunching, but by nature don't naturally tend to do as much analysis as needed. As yet, I still haven't given a tremendous amount of thought to what my heat load is etc. I know that we are getting by in the house with a stove rated at 40kBTU. That is not enough to keep the house comfortable in all corners in really cold weather. But it has kept us from freezing up for about 35 years. The shop I only heat when I am willing to burn enough wood to heat it. (Better insulation is in the works). My approach to a boiler, is put in a good sized unit with lots of heat storage, and then figure out the distribution. I would like to have capacity for an addition or two on the shop, which would get in slab heat. I haven't yet made much of a decision about how to heat the house. It wouldn't take much to be an improvement on what we have now, and I am not sure how much I want to stick into the present structure. I would be almost ready for a major rebuild. Also it is not out of the question that another residence might be added, so some reserve capacity would be welcome.
To me, the most complicated part of this upcoming heating system will be the figuring out of the pumping, mixing, tempering, and control of the whole system. I will hope to avoid unnecessary complication. Not to mention the various choices available for heat emitters. I will try to ere toward the readily available, salvage, and cheap alternatives ex. (used cast iron rads).