Boiler Heating Question

Discussion in 'HVAC Heating & Cooling' started by Master Brian, Nov 22, 2008.

  1. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    I am restoring a house built in 1915, which has no heat on the 2nd floor, except for a baseboard heater and space heaters. I am searching for ideas to heat this space, which is about 700sqft.

    I have been toying with the idea of installing a PEX radiant floor system to supplement my main floor and possibly basement walls. Main floor is about 1400sq ft, basement is about 700-900sq ft. If I pursue this route, one idea I have for heating the 2nd floor is trying to get some radiant heat via Pex tubing to parts of the 2nd floor area.

    My brothers house, about the same age, still has a boiler which heats his main level via the old cast iron radiators. I have a source for these heaters, could I install a modern boiler, using PEX tubing and hook them to the cast iron radiators?

    Also, what is the approx cost of a boiler that would handle a radiant system on a house 1900sqft with a 700sqft basement. Also, size wise what would I be looking at?

    Can anyone point me in a direction to search for more information and is this a viable option to a forced air system? I still need to figure out an A/C, unless I stick with a window unit....

    Thanks....
  2. nhmaster

    nhmaster Master Plumber

    Messages:
    3,189
    Location:
    S. Maine
    Brian; My house is 200 years old. When we moved in 12 years ago it had copper fin tube baseboard pretty much wrapped around every room. Made placing furniture a real hassle. I tore out the old Crown boiler and installed a Buderus and then tore all the baseboard out and put in cast iron radiators. I fed each radiator individually with 5\8 heat pex run back to manifolds on the boiler. One for the first floor and one for the second. I did it that way because I didn't want to deal with a monoflow system and looping radiators is very restrictive flow wise. Also used Taco's zone control with their PC700 modulating control. System works super and is very efficient, Plus you can dry wet boots and gloves on the kitchen radiator :D
  3. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    Thanks for the response. Glad to know I am not completely crazy with my thoughts. I don't seem to have a Buderus dealer in my state, but I'll look into them. Any idea of how large a boiler I would need to effectively heat around 2300sq ft?

    Without knowing much at this point, this is what I am thinking...

    2-3 cast iron radiators to heat my 500-700sqft basement, they would probably all be on one zone. Then maybe 3-6 radiators on the 1st floor on one zone and then radiant floor heating throughout the 1300sq ft first floor, probably 1-3 zones. Then 2-3 radiators on my 2nd floor, which is about 600+sqft. They would be on their own zone.

    I also like the idea of running each feed seperately, that would actually be easier for me.

    One of the main things, I'd like to know is approximately what would the footprint of the boiler be? I am currently working on part of my basement and sectioning off what will be my utility room. I'd prefer any boiler to go into there.

    I am looking on their site, but not finding info yet and I don't know which unit to look into.

    Thanks again.
  4. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,344
    Location:
    New England
    A well-insulated 5000 sq ft house could use 1/10th the energy a drafty 1000 sq ft house needed, so size has little to do with the size of boiler needed.

    First thing you need to do is either perform or have performed a heat load analysis of the house. This takes into account the worst case outside temps, the desired inside temps, the amount and size and quality and location of windows, the amount of insulation in the walls and ceilings, and often other factors. WIthout knowing that info, you are just taking a shot in the dark.
  5. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    Understood!

    I guess I didn't really take that into account, since nobody has ever done one, when they installed a new furnace, so I really didn't think about that.

    I just did a quick guestimation based off the paperwork I had when my house was appraised, when I bought it. I realize it is not real accurate, but it should give a ballpark, realizing that this won't be the only heat source and may not be the main. I know enough to input figures, but not enough to know what the output figures are. I would think this will actually be a fairly tough house to figure because of the age. Wood siding, large old windows, lath/plaster walls, unknown insulation in walls, 1x4 solid wood subfloors with 1" solid hardwood flooring on top, ect.... They don't ask those questions on the online software!

    It gave me an UA(BTU/hr-F) of 387, a Design Loss(BTU/hr) 30960, and a yearly heat loos(BTU/yr) of 41796000. There is a lot more info, but that seems to be the whole house numbers and what I'd guess someone would use. The yearly heat cost figure, is actually pretty close to what I actually use, so I'm guessing this is pretty close for a quick run through. I'll get a more accurate measurement one of these days.

    I look at Buderus' website and don't see anything that really compares. What are some other good brands? I'll search for local installers of those. I'd have to order a Buderus online, so it'd probably be tough to have professionally installed, unless these are pretty straight forward installs.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,344
    Location:
    New England
    Any of the condensing, high efficiency, modulating boilers are sticklers for proper installation (which include the setup of the electronics). Not a good thing unless you are familiar with them or are quite technically proficient. The defaults probably would work, but you'd not be getting the efficiency you paid for.

    I also chose a BUderus, partly because their US headquarters is about 15-miles from my house, and partly because I liked the way it worked. Second season, and no problems.

    Vie$$man, Weil McLain, and several others make similar units.

    If you are looking for a federal rebate, last I looked, those are only available in larger units. Local utilities are often providing rebates, so look to see what they are offering. I replaced both the boiler and indirect WH, and got $1100 back from the local utility company, which helped.
  7. Master Brian

    Master Brian DIY Senior Member

    Messages:
    368
    Location:
    Kansas
    I consider myself fairly technically proficient, but I'm not sure I'd want to tackle it alone. I do want the basic knowledge, so I know what to get.

    I'd like to find either a professional, that didn't mind me doing some of the work or someone that does this on the side as well. There are certain things I don't mind paying for, but other things that I don't want to pay $50-$150 per hour for someone to do grunt work type stuff that I can probably do faster and better. If I knew what type to get, I could order one, such as the Buderus, online and have it delivered Then I'd just have to pay someone to "hook it up" after I terminated the PEX tubing at the boiler.

    Thanks for the rebate ideas as well. I didn't realize all those were available. That would definately help.....

    Any of you near the Wichita, KS area and interested in setting one up?
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