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Twining boilers

Snowmelt
Snowmelt Member Posts: 1,387
If you had a chance or the opportunity would you for redunicy I went to a house with 22 radiaters and 150,000 net would you use 2 - 75,000 boilers or 1 - 150,000 btu unit, either weilmclain, utica

Would you use zone valves and thermostates or thermostatic expansion valves.
Or would you zone just the floors? Or would you again for redundancy use 3 pumps one per floor then zone valves?

Comments

  • unclejohn
    unclejohn Member Posts: 1,829
    I would definitely use two boilers and it should be a easy sell. But times are very tuff and some people don' have the extra money even though in two or three years they will get in back in savings. And the set up should make the boiler last longer.
  • Snowmelt
    Snowmelt Member Posts: 1,387
    How would 2 boilers save gas?
    The walls are torn down so I can get a thermostat in every room and put the rads on a manifold, either I make one with propress or I get a few radiant manifolds with power heads on them.
  • Zman
    Zman Member Posts: 7,446
    It is much easier to match the load. If you are using a traditional 2 stage boiler, you now have 4 stage control. A 5 to 1 modcon become a 10 to 1. Great for efficiency and longevity.
    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    SWEIRobGBobbyBoy
  • Snowmelt
    Snowmelt Member Posts: 1,387
    It's currently piped with moniflow tees in basement. It's rehab house now. The boiler is out, all the pipes are froze. And the owner is going to get all the rads pressure tested and painted. I'm going to assume new shut off at the rads. He'll even the chimney is out. All the brick is all over the place.
  • Snowmelt
    Snowmelt Member Posts: 1,387
    Z man thanks for that little bit of info, in my head I actually said that to my self that I have a lower minimum.
  • wogpa67
    wogpa67 Member Posts: 238
    And since the chimney is gone looking better for 2 mod cons with an indirect.
  • icesailor
    icesailor Member Posts: 7,265
    In theory, this is all a wonderful thing.

    Have any of you ever priced out something like the whole enchilada and also from the very basic taco shell and added all the frills that go into it to get the whole Enchilada? Like a basic Pizza and all the extra toppings you want? What YOU might want, may not be the same as what the customer might want.

    If you just price two boilers over one boiler, will the difference in cost for two be paid off in the lifetime of the boilers? In heat savings? "Efficiency's" are a fleet of ships. I put a more "efficient" AC replacement system in my home and it cost me more to run. But it IS more "Efficient". Maybe in the mechanics of operation, and extracting cash from my wallet.

    If that house froze up to the extent that it sounds like, 20% or more of the radiators are cracked and broken. Maybe even 100%.

    Customers with freeze ups are dealing with insurance companies. The customer needs a regular pizza and they want a large Pizza with "The Works", with all toppings. The Insurance is going to Pro-Rate a small, regular pizza, no toppings. The customer is going to have to pay for all the extra's. When they get estimates, they usually croak and go with whatever they decide they can afford. Like Scorched/Iced Air.

    The installer that knows this, prices a regular pizza and then lists all the extra toppings and their cost. So the customer can see the differences. If you don't, someone else will be replacing boilers. Does anyone know the total cost added to simplicity with this stuff? Just TRV's added to 15 radiators could be near the cost of a boiler. For what? When they are on the floor, do you want to control the floor temperature or 4' to 5' above the floor? Look at Hurricane Sandy. The shysters moved in and they were installing anything they could get in their truck and in to the cellar. The good guys (like us) get to drive by and watch people get butchered.

    That's just like doing a new house. A frame that needs mechanicals.

    Maters squat to me. I've repaired enough screw-ups by others that caused freeze ups. I know the game well. Been there, done that.
  • SWEI
    SWEI Member Posts: 7,356

    A thermostat will always regulate room temperature better than a TRV.

    Really? Not in my experience.
  • clammy
    clammy Member Posts: 2,912
    I think if the money was there i would do 2 mod cons piped into at least a30 gal boiler buddy .as for the rads i would do 2 remote manifolds and use pex al pex w trv as for pumps wilo eco if no by pass at rads .I would use a indirect tanks for domestic and i would make sure to add a magintic dirt seperator to the inlet of your boiler or boiler .Are you re using the rads or are you going for steel panel rads .I personal like the buderus panel rads and there overtroup by pass raditor isolation valves .It s real nice on a constant circ system where they keep low temp in some rooms never have to worry about your runs frezzing always circing when the trv is closed .Peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • vaporvac
    vaporvac Member Posts: 1,520
    This seems like a perfect opportunity to install GG's Mini-Tube system! No worries about freezing then, and twinning really makes sense. Depending on the size, two "residential" boiler/burners can run less that one single commercial unit. That was my experience, anyway.
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • SWEI
    SWEI Member Posts: 7,356
    On/off control simply can not maintain a tight setpoint in most systems. If you have just the right amount of mass and just the right amount of integral in the stat algorithm, it can get close.

    Proportional control works so much better. Once you throw ODR into the mix, it becomes pretty much mandatory IMO. On/off control simply can't deal with the slow rate of room temp change that comes from starting or stopping the flow of water (or air) that's only a few degrees away from the measured room air temp.

    TRV's are the simplest, least expensive form of proportional flow control I know of. Proper placement is essential, and the remote heads are kind of a PITA to install. I can do better (much better, actually) using a proportional control valve and the right logic to manage it.
  • clammy
    clammy Member Posts: 2,912
    Not to drag a dead horse but what are the thoughts on steel panel rads with the tvr mounted up off the floor like on buderus or dianorm panel rads .I have used them and have them in my own house and properly placed i have had no real temperture issues .Sure seems easier then running stat wires( unless electrician is gonna handle it LOL),stats and then mounting accuator heads on mainfolds plus some people don t even like to see stats we give them remote sensors and mount the stat some where unseen .More money more money trvs a bit easier very common else where in the world no where money and people are a bit more frugal ? peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • clammy
    clammy Member Posts: 2,912
    not to argue w ya but i do remenber a programable trv head years ago in catalog it may have been overtroupe or another european manafacture not sure .I m kind of a mech guy love the way the europeans can install a system with exposed piping and do it correctly and is non instustive on the living space .They also insulate the heck out of every pipe in the system and on large jobs love those reverse return systems there mechincals always win and there isn t as many opitions and i believe there standard of mostly panel rads and towel racks for baths must have some merits being they seem to be doing them now for about what 25 years or more .This is from some where where fuel weather gas /oil and electric is quite expensive as in comparision to what pay .I ve switched my own home to panel rads w trv and sized them to 140 swt installed a mod con and now with the coldest weather to hit my area in a while my gas bill is 80 bucks .can t beat it those europeans know what works with what and how be squeze that euro or dollar my own system has proven it to me .The few panel rad jobs with mod cons i have sold and install have seemed to make my custermers very happy with high comfort levels and much lower bills then there previous systems most of which where not even close to being installed by anyone with a clue if you gey my drift .peace and good lucl clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • Gordy
    Gordy Member Posts: 9,537
    Unless this is a hydronically educated customer, and a request of such to have two boilers I think you will price yourself out of a potential job.

    Trvs deffinetly.

    Redundancy? I don't own two cars in case one breaks down. I own two because I need two.
    icesailor
  • Fred
    Fred Member Posts: 8,541

    Gordy said:



    Redundancy? I don't own two cars in case one breaks down. I own two because I need two.

    LOL. I own three in case one breaks down................
    Ha, Ha, Ha! I know @Hatterasguy has called me wierd before because I have a steam boiler and two forced air furnaces (strictly for central air and backup to the boiler) but I too have two trucks, in case one breaks down.
  • Gordy
    Gordy Member Posts: 9,537
    So to pay license, and insurance on back up vehicles is cost effective as to owning one thats dependable
  • Gordy
    Gordy Member Posts: 9,537
    Not being Stupid, but I think you get my drift. Why maintain two boilers when one can easily do the job.
  • Fred
    Fred Member Posts: 8,541
    Gordy said:

    So to pay license, and insurance on back up vehicles is cost effective as to owning one thats dependable

    Everything isn't based on dollars alone. Both of my trucks are very reliable but I live alone and don't want to be a burden on anyone if/when I have a problem so I try to prepare myself, my home and my needs so as to be s independent as is humanly possible. Besides, I like toys and none of us live forever. I've been retired 8 years now so I'm gonna have what I want (within reason).
    Installing my furnaces was practically no cost because I was going to have central air, regardless and the cost of the furnaces over just air handlers was practically zilch.
    I do think there are some advantages of two smaller boilers over one large one but the opposite is also true. As has been said, the homeowner has to weigh what is important to them and decide.
    BTW, when you are the only licensed driver in a household, the cost of insurance is just a relatively small incremental amount (at least that is my case).
  • Gordy
    Gordy Member Posts: 9,537
    The analogy was taken into left field. The point obviously is redundancy has its place.
  • Fred
    Fred Member Posts: 8,541
    Gordy said:

    The analogy was taken into left field. The point obviously is redundancy has its place.

    Understood