Hello, I've been ready A LOT of threads that touch many of these topics and I must say this is a wealth of knowledge - THANKS! However, I am still left thinking - am I doing the right thing? So hopefully my explanation and your (collective) expertise will assuage my fears! OK - on with it!
My current setup -
Colonial house, built 1994, Long Island NY
Gas fired Weil McLain cast iron boiler CGM-5-PI Series 10, circa 1995 (atmospheric vent up chimney flu)
Input, Btu/hr - 140000
DOE Heating Capacity, Btu/hr 115000
2" Cast Iron supply (about 6' worth) heading to 2 zones (upper and main floor), flow-checked and 1" each
The 2 zones are both monoflo loops spanning the whole basement with 1/2 taps going off to the rads
Radiators are all Burnham "Baseray" cast iron baseboard or Burnham "Radiant" cast iron uprights.
Each zone gets a circulator on the return side, just before the boiler. B&G series 100's for both.
The house gets warm, no problem. So why mess with a good thing?
A basement renovation.
Flushing up the current situation in my joists would be crazy work - so I may as well be crazy and remove the monoflo loops and home run each rad back to 3 manifolds (upper floor, main floor, new basement reno.) So, each manifold is for each floor. I will be doing the home runs in 5/8 pex-al-pex (to match the 1/2 copper legs for the rads). My original idea was to simply use some grundfos alphas in front of each manifold and tie them each to a thermostat, but then I got worried about the returning water temperature being too low. Currently, with all the water sitting in a cold basement in the monoflo loops, the water coming back is cold to begin with - this isn't good for my boiler, right?
So my next idea was a bit more future focused. One day, this boiler is going to crap out, and perhaps I would change it to a modcon, or not (maybe just another cast iron.) Since I do not know yet, why not install the prerequisite Primary/Secondary loop layout and give myself some options down the road? Wouldn't this benefit my current boiler anyway? The return temps would be stabilized more and I could possibly add a DHW down the road as well.
So, I thought out a new layout -
Current boiler (primary) supply and return repiped in copper 1-1/4" with a taco 00e VT2218-HY1-FC1A01 primary circulator heading to a hydrolink.
OK - the logic here is that this taco circulator pays attention to deltaT and can be set in such a way that it will know whether or not it needs to move the primary loop water through the boiler to maintain a nice deltaT, while not going crazy. Is this a good idea?
Heading back to the hydrolink, that is where my zones will be piped from - 3 zones, one for each floor using caleffi 1" manifolds. My top floor will use a 6 loop manifold, my main floor will have a 10 loop manifold, and the new basement will have a 6 loop manifold.
each zone with be circulated on the supply (hot) side by a grundfos alpha (3 of em)
The logic of using the alphas is to achieve the proper head flow for these manifolds. I am not about to try to math out all this pipe for all these rads!! Head hurts too much!
As far as a switch relay, I need the most help here - I was thinking a taco SR506-EXP
This would work with my current boiler, with what I am trying to do right? Also, it would allow me to grow into a modcon if I went that route down the road as well I think.
Main contentions of going this way (overkill) was to accommodate an outdoor temp sensor, a future DHW (with priority) and perhaps one more zone, if needed.
I am hazy on how the boiler will behave in this new ECM world, where to me it seems I can let the primary circulator turn on and off based off of its own intelligence and modulate the boiler firing on its own as well....? Is this crazy talk? This is the one part I have yet to sink time in to.
I think this about sums it up, AM I CRAZY?
My current setup -
Colonial house, built 1994, Long Island NY
Gas fired Weil McLain cast iron boiler CGM-5-PI Series 10, circa 1995 (atmospheric vent up chimney flu)
Input, Btu/hr - 140000
DOE Heating Capacity, Btu/hr 115000
2" Cast Iron supply (about 6' worth) heading to 2 zones (upper and main floor), flow-checked and 1" each
The 2 zones are both monoflo loops spanning the whole basement with 1/2 taps going off to the rads
Radiators are all Burnham "Baseray" cast iron baseboard or Burnham "Radiant" cast iron uprights.
Each zone gets a circulator on the return side, just before the boiler. B&G series 100's for both.
The house gets warm, no problem. So why mess with a good thing?
A basement renovation.
Flushing up the current situation in my joists would be crazy work - so I may as well be crazy and remove the monoflo loops and home run each rad back to 3 manifolds (upper floor, main floor, new basement reno.) So, each manifold is for each floor. I will be doing the home runs in 5/8 pex-al-pex (to match the 1/2 copper legs for the rads). My original idea was to simply use some grundfos alphas in front of each manifold and tie them each to a thermostat, but then I got worried about the returning water temperature being too low. Currently, with all the water sitting in a cold basement in the monoflo loops, the water coming back is cold to begin with - this isn't good for my boiler, right?
So my next idea was a bit more future focused. One day, this boiler is going to crap out, and perhaps I would change it to a modcon, or not (maybe just another cast iron.) Since I do not know yet, why not install the prerequisite Primary/Secondary loop layout and give myself some options down the road? Wouldn't this benefit my current boiler anyway? The return temps would be stabilized more and I could possibly add a DHW down the road as well.
So, I thought out a new layout -
Current boiler (primary) supply and return repiped in copper 1-1/4" with a taco 00e VT2218-HY1-FC1A01 primary circulator heading to a hydrolink.
OK - the logic here is that this taco circulator pays attention to deltaT and can be set in such a way that it will know whether or not it needs to move the primary loop water through the boiler to maintain a nice deltaT, while not going crazy. Is this a good idea?
Heading back to the hydrolink, that is where my zones will be piped from - 3 zones, one for each floor using caleffi 1" manifolds. My top floor will use a 6 loop manifold, my main floor will have a 10 loop manifold, and the new basement will have a 6 loop manifold.
each zone with be circulated on the supply (hot) side by a grundfos alpha (3 of em)
The logic of using the alphas is to achieve the proper head flow for these manifolds. I am not about to try to math out all this pipe for all these rads!! Head hurts too much!
As far as a switch relay, I need the most help here - I was thinking a taco SR506-EXP
This would work with my current boiler, with what I am trying to do right? Also, it would allow me to grow into a modcon if I went that route down the road as well I think.
Main contentions of going this way (overkill) was to accommodate an outdoor temp sensor, a future DHW (with priority) and perhaps one more zone, if needed.
I am hazy on how the boiler will behave in this new ECM world, where to me it seems I can let the primary circulator turn on and off based off of its own intelligence and modulate the boiler firing on its own as well....? Is this crazy talk? This is the one part I have yet to sink time in to.
I think this about sums it up, AM I CRAZY?