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Old cast iron system upgrade design review/help
New to the forums, but I've been lurking for a while since I bought my old house almost a decade ago. This forum has been instrumental in helping me understand my 90+ year old hydronic heating. So thank you. Now to the fun part, bringing this old system to the 21st century... For starters I've called probably 15 or more HVAC companies around here that claimed to be knowledgeable in hydronics and have been met with liers, cheats, people to busy to even return my calls, or people giving me astronomical bs estimates over the phone. Oh and those who do come out shy away from the project. So I'm left to attempt this on my own.
~30yr old Weil McClain CGM-5 series 9 140k input 115k btu output. Old and WAY oversized but shes in good shape and still kicking strong so she stays put for now(hopefully until after I insulate the house)
For heatloss I once spent a night recording run times on a very cold Janurary night a few years back. At ~3F the boiler ran for about 35min/hr. When I worked out the math it came out to around 67k BTU/hr. I've also noticed when we get below 0 the aquastat shuts off the burners(for some reason its set to 150f). After I used a worksheet to calculate the outputs of all the radiators it made perfect sense. They were sized correctly for the design temp even 90 yrs ago. Cleveland design temp is 5F if I'm not mistaken.
All CI radiators on 2 two pipe loops(one loop front and one for the back of the house) And just recently had an abatement company remove all the old asbestos pipe insulation. so I'm clear there as long as I don't cut into the walls.
Radiator sizes @ 140f:
Living rad1: 4500btu
Living rad2: 5300btu
Bath down: 2700btu
Master bed: 8900btu
Front bed: 6400btu
Back bed: 7700btu
Bath up: 5700btu
Downstairs: ~32.5k btu
Upstairs: ~28.7k btu
Total: ~61k btu
The plan: I'm wanting to setup primary/secondary loops with a 4 way mixing valve to give me ODR and boiler protection. The secondary would have 7 zones with only 5 actually setup, the other two for future expansion into the walk up attic, and full basement. The Primary would have a second set of closely spaced T's that are capped off for potential indirect DHW. Current gas hot water tank is already 12yrs old. I would be using zone valves and a zone controller plus a infinite variable ECM system circulator. The boiler circulator that it currently uses would remain. I would however move the expansion tank so the pump is pulling from it and a new air scoop. Other features I want to add are lots of isolation valves. One for each radiator and other service points in the system. Differential by-pass(not really needed because of my choice in circulator but for 30$ w/e), drain valve, flow check, and wye strainer.
Each bedroom would be its own zone with thermostat, and the main floor would be on its own. Because of the number and size of radiators on the main floor I would run a 1" supply to a seperate manifold. 4 1/2" and 1 1" zone valves and 28 isolation valves. Did I mention I wanted a lot of isolation valves? I do not want to be caught in the middle of january with no heat a whole day because I have to drain the entire system because of something stupid EVER again.
Here are a few pictures and a couple plumbing schematics. Please don't mind my horrible hand drawing and writing.
Edit: Forgot to add the reason I'm doing this is both to free up space in the basement, I've hit my head one to many times and would like a man cave. Also when I set it to a comfortable 72 downstairs I sweat balls in the master, or of my room is comfortable there are cold feet downstairs and the other bedrooms get chilly.
I would also be using 1/2" pex-al-pex to each rad. And on my diagram I forgot to draw the isoltion valves around the boiler.
My biggest concern is how small the bedroom zones are relative to the boiler. When I replace and downsize the boiler and/or add DHW it would be less of a concern. Until then I might tie multiple zone valves together just so keep the boiler from short cycling.