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New house construction, please help with choosing boiler/ DHW on LP

danlin
danlin Member Posts: 15
edited March 2015 in Gas Heating
Hi, I'm in planing stage of a new house construction. It's going to be a two-story, around 2K ft², 48k total heat loss, 86 ft of baseboard. I'm trying to come up with an efficient, reliable set up, that will run on a well water. NY has a fourth-highest prices on electricity nationwide so I figured a LP would be a better choice of fuel to use. With so many options available, I'm lost. Someone suggested a Rinnai combi unit, but I'm not sure it will provide enough DHW for the family of five (including three teenage boys), then there's Baxi, Weil McLaine, Noridz, Utica ... Do I do a combi? Or a bolier and a separate DHW tankless? I have an experienced plumber friend, who will help with installing. Any suggestion will be greatly appreciated.

Comments

  • clammy
    clammy Member Posts: 2,668
    A direct vent modulating condensing unit with a seperate indirect would be my choice on new construction.I would how ever look at designing my heating convectors to operate on a much lower supply water temp.Most modulating condensing boiler operate at higher eff with lower water temp and have far less issues as compared to hi temper applications just my experence .I have installed baxi and was not to happy had a few service issues ,the brand is not usually a issue just make sure that whos ever unit you install that your buddies comfortable with handling the service and set up and that parts are easly accessable . i would look at triangle tube , viessemann and as much as others have opions peerless purefires i have a few out there and have had a good run with them but that is me. Just about every mod con out there will recommend primary secondary piping dont skimp i ll save you to regreat it .Do some reasearch and educate yourself there splently of great mod cons out there but alot depends on the installer that is where promblems happen if done right there s no issue done wrong and you will hate what ever unit is put in.I personallywould go with a mod con (got one in my own home close to 9 years ) and either add alot of baseboard to lower your water temp or take a look at some panel rads by buderus ,easier zone and room by room temp controll and you don t have to look at crappy dust bunny collecting baseboard plus you will get to have floor moulding instead .Other beautiful thing is they sort of blend into any room and are up off the floor and you can size them with lower entering water temp meaning heigh eff for your mod con .Sorry if it s alot of info but your building it do it right and have a surprise in the future your fuel bills will reflect the real eff of your sysyetm no. Keep also in mind that these boiler will come with outdoor reset make sure it s installed and programmed it does make a difference . peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
    danlinHatterasguy
  • Rich_49
    Rich_49 Member Posts: 2,611
    It would seem that you are thinking of using high temps to achieve this with 80 feet of baseboard . While this is standard thinking I would say that using a AWT no higher than 140* at design should be the goal with baseboard . Flowing at a 20* Delta T you will still be condensing at design and enjoying even higher efficiencies the remainder of the year . Using a mod con boiler or combi with these high water temps will leave you with efficiencies south of 90% .
    Please read the following , I have linked to it to give you a chance at what you appear to be trying to achieve .

    http://www.emersonswan.com/ckfinder/userfiles/files/High Eff Guide.pdf

    Your thought about how the combis will serve you is fairly accurate . Look at the indirects with boiler first , you will not be left with a cold water sandwich as with others .

    Baseboard of sufficient quality to make your boiler more efficient is a one time investment and tubing to run parallel pipes to each baseboard is similar . Don't let your first cost outlay cost you money every year . One choice is certainly money well spent , especially if you are limited to LP .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • danlin
    danlin Member Posts: 15
    Thanks both of you! I appreciate your response and great info. I'm an amateur in this area and any input from a professional makes my task much easier.
  • tim smith
    tim smith Member Posts: 2,398
    I am totally on board with what Clammy and other said. The only other boiler I might throw in mix is the Lochinvar WHN series (only one I would choose from there lineup) really good boiler, basically same as Triangle. I know they are more dollars but look at Runtal UF series radiators sized for heat loss and design temp of 140 max. Will keep your boiler in condensing most if not all the time. Use an indirect water heater off boiler, Either Lochinvar squire or HTP superstor. Those are just my faves for quality/value. That's my .03 worth. cheers. Tim
  • danlin
    danlin Member Posts: 15
    Thanks Tim! How many Btu's should I allow for an indirect water heater so it's enough for my family and how big of a storage tank?
  • tim smith
    tim smith Member Posts: 2,398
    edited March 2015
    I would think a whn 085 and a 60 gallon indirect is a decent choice. You could probably go to next size down boiler but dhw recovery might be a bit slim.
  • RobG
    RobG Member Posts: 1,850
    I would go with the Lochnivar WHN055 and an indirect, just increase the temp and use a mixing valve to extend your hot water. I can't tell you what size indirect without knowing the hot water requirements.
    SWEI
  • danlin
    danlin Member Posts: 15
    Tim, Rob - thanks a lot! This info gives me something to work with.
  • Youngdogs2
    Youngdogs2 Member Posts: 14
    Danlin -

    One big question I would have asked is how many bathrooms are you supplying? What other fixtures are there in the home? Based off this information, you then can decide if a all-in-one- Combi is the way to go or if an indirect attached to your heat only boiler is the best course of action. Don't fear the tankless style of boiler like the one's you originally mentioned. They are all good as long as they have been installed and set up correctly. Also if you go with a Modcon type boiler do yourself a favor and install a simple cartridge filter prior to the boiler to pick up any debris from the water supply. Last the tankless portion on the boilers you mentioned, Rinnai and Baxi will handle the hot water needs for a family of five....no problem.

    Good Luck!
  • GW
    GW Member Posts: 4,304
    edited March 2015
    Yes that's like posting a question on a Muscle Cat forum with "I have some bucks for a 1960s muscle car, what should I buy?". There are many correct answers. There are many "not so great but sure whatever floats your boat" answers.

    A combination boiler will work if your family understands the limitations. An indirect is best for good Ole "give me lots of hot water and give it to me now". But you can run an indirect cold.

    If you want a nice system, go with panel rads, I have installed hundreds of panel rads from hydronicalternatives.com. Baseboard is a little bit old school, it does the job but you may wish to pump a few extra grand into a nicer heating system.

    edit- correct spelling of my name
    Gary
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Henry
    Henry Member Posts: 988
    If you are in Northern NY, it is similar to Montreal. You need 120,000 max for the coldest 10 days. We do over 200 boilers a year from high end house to major commercial and industrial installations. My design for a similar house would be a HTP EL 150 with a SSU60. It has to be piped P/S and a Grundfoss or Taco pump selected for 25 F Delta T. You wont run out of heat at -20F nor of hot water for the family. But, if you have a a rain forest 12 inch shower head minus the restrictor or a full body 6 head shower, you will need to up that. I had to put in a SSU119 instead feeding off a KBN500 that also did snow melt due to the large showers.
    htproducts.com/literature/lp-81.pdf

    Here is the garage with turnstile for the cars, Wolf BBQ, Plasma screen and of course radiant heat in the floor.
  • Gordy
    Gordy Member Posts: 9,514
    The OPs heat loss is 48K. Why are people suggesting boilers of 85K-120K???
    Rich_49RobG
  • danlin
    danlin Member Posts: 15
    There's going to be 2.5 baths, dishwasher and washer machine as for the fixtures. Also 48k heat loss does not include the full walk-out insulated Superior Wall basement, where I will do a radiant heat in the slab. The problem is, it's a modular home and there is no choice for baseboards. The company just provides conventional ones. The second floor, where all 4 bedrooms are, is one single zone. For the first floor they just do stub-outs into the basement, and it's my responsibility to connect them as I wish. I'm thinking to redo the first floor later with radiant heat (easy access from below). Thanks for all the suggestions, I learned a lot on this forum from the posts off all of you good people. I'm thinking a whn 085 or equivalent and a 60 gallon indirect, as Tim Smith suggested above, should work for me.
  • njtommy
    njtommy Member Posts: 1,105
    Don't forget a buffer tank your going to need it being that your minimum firing rate on the boiler is 18,000 btus. The last thing you want to do is short cycle the boiler.
  • GW
    GW Member Posts: 4,304
    can you simply have the factory not install the 1st floor baseboard? It's ok, but, that's just it, it's ok. Go with your own panel radiators for a better heating system.
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Paul48
    Paul48 Member Posts: 4,470
    You need to have a sit-down with the owner, and or, the engineers. With that heat loss and that many feet of baseboard they are locking you into an average water temperature of 170*. That's completely out of step with modern, advanced heating systems.
    Gordy
  • Gordy
    Gordy Member Posts: 9,514
    edited March 2015
    I have to ask Who, and how the heat loss was done?
  • Paul48
    Paul48 Member Posts: 4,470
    They should have a pretty good handle on that Gordy. They're building it in a factory.
    Charlie from wmass
  • Gordy
    Gordy Member Posts: 9,514
    Uh huh,
  • Paul48
    Paul48 Member Posts: 4,470
    LOL....One would think, anyway.
  • SWEI
    SWEI Member Posts: 7,356
    danlin said:

    There's going to be 2.5 baths, dishwasher and washer machine as for the fixtures. Also 48k heat loss does not include the full walk-out insulated Superior Wall basement, where I will do a radiant heat in the slab.

    So you obviously need the heat loss for the basement. Add that to the 46k and do the math for the DHW. If a moderately large indirect won't cut it, consider adding a condensing tankless -- either alone or as a booster. NG or LPG? Fuel prices? Any utility incentives?
  • danlin
    danlin Member Posts: 15
    Here is a quote from another post:
    "I used an Ergomax 44 gallon as a buffer tank and to produce DHW. With this in the primary loop, the temp set points can be adjusted along with the differential to reduce short cycling. Also it provides a large reserve of boiler water to the radiant floor and for DHW. The tank's standby loss is quite small. Also when the panel rad loop is turned on, the cold returning water is mixed with hot tank water before going to the boilers." (\"Maine\" doug)
    So I can do a buffer tank and use it for hot water too, instead of an indirect?
  • danlin
    danlin Member Posts: 15
    If someone could sketch me a diagram of my potential setup, with two zones for baseboard (44' first floor, 42' second floor), a radiant zone in the basement, and an indirect or buffer tank, that would be so awesome.
  • Jason_13
    Jason_13 Member Posts: 299
    edited April 2015
    I would use the US Boiler Alpine or K2 wall hung which both turn down to 16k along with the new zone panel they are introducing next month. You can program the heat loss per zone and it will limit the boiler to that output. For instance a 20k zone will limit the boiler to 20K and allow modulation down. This will increase the system efficiency. I have heard good results on test units over the last two winters.
  • danlin
    danlin Member Posts: 15
    Thanks Jason, I'll take a look.
  • ProblemSolver
    ProblemSolver Member Posts: 190
    Sorry if this was already said; I didn't read every thread, but what I did pickup was you are stuck with the baseboard because the modular home builder gives no other options. Consider this: the Europeans do not use "baseboard" because baseboard is not efficient. Baseboard only heats by convection - air movement. The other radiators that the pros were suggesting do convection and radiant heating at a lower temp. I know it's hard for you to understand the differences without experiencing them, but the radiators are like having a meal at a high end restaurant and the baseboard is like having a meal at a coney island restaurant. The quality of heat/comfort/efficiency is night and day.
  • ProblemSolver
    ProblemSolver Member Posts: 190
    What truly determines your comfort and the boilers efficiency in a hot water (hydronic) system is 100% determined by the heating elements that are used. Heating Element types: radiant floor - wall - ceiling; cast iron radiators; steel radiators, fan coils, baseboard. Baseboard is at the bottom of this list for comfort and efficiency. But I would prefer baseboard over force air heating; partly because it's easier to zone. But if you are truly stuck with baseboard, then consider zoning with pumps instead of zone valves, and size the pumps correctly to get the most out of the baseboard. Too small or large of a pump will cause you higher gas bills.
  • hot_rod
    hot_rod Member Posts: 15,037
    Fin tube baseboard is no doubt the most common hydronic heat emitter you will come across. They are an excellent emitter when you consider cost, installation, and ease of zoning.

    They transfer energy mostly by conduction, cooler air enters the bottom of the fin, it's heated by the fluid in the copper tube and it rises up and out as the warmer air is less dense. They do a great job of "blanketing" exterior walls with heat energy and are very comfortable heat emitters.

    The main drawback is the traditionally run with high supply temperatures, often around 180°F, maybe higher. As a result they encourage stratification, with warmer air trapped at the ceiling, and require high, less efficient operating temperatures at the boiler.

    The good news lately is the design and use of much lower temperature fin tube. This can greatly reduce the stratification effect. It also allow much lower water supply temperatures and helps leverage the modern low temperature condensing style boilers. So you operate at higher system efficiencies, and greater room comfort. Fin tube is not a great match for high ceiling rooms, in you case it sounds like it would work fine.

    If you have input in the system design, have it designed around low temperature operation, 130°F or lower would be great. Connect it to a high efficient, modulating style boiler with reset control.

    For zoning, I'd go with a single circulator, ECM delta P style, and zone valves for the control.

    While many would argue that radiant surfaces are more comfortable, they do come with a higher price tag, generally.

    A properly designed, installed, and controlled fin tube system is still an excellent means to heat a home or building.

    Look into products from Heating Edge, SlantFin, Jaga, and other common fin tube brands. They are all embracing lower temperature operation and offering very nice products to help installers sell clean, quiet, comfortable baseboard systems.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    RobG
  • ProblemSolver
    ProblemSolver Member Posts: 190
    When you consider just the up-front cost of baseboard compared to radiators, the baseboard wins every time. But when you look at the operating cost across 10 years, 20 years, 30 years, it's a whole different animal. I removed the baseboard from a family room / kitchen zone (on a cement slab), and installed Myson radiators in their place; at a very good friends house. First of all; with the baseboard, their kitchen and family room was never comfortable even with that zone running more often than the other 2 zones. After installing the Myson radiators for the family room and a toe-kick heater for the kitchen, their reply was - "we never thought this area could get this comfortable, we can now watch TV in our birthday suits if we wanted too." Plus, this zone is now the one running less often than the other 2 zones. They do not regret the higher up-front cost; not one bit. Their gas usage went down and their comfort went way up. You have to experience it to understand it.
  • ProblemSolver
    ProblemSolver Member Posts: 190
    Another draw back to baseboard is it only heats the air that passes through it. The steel radiators not only heat the air that passes through it, but also provides radiant heat as-well. They will heat the furniture, and the floor within its vicinity by way of radiant heat waves; then those items will release their heat to the air around them giving the room a much more even temperature.

    The Europeans pay 3 times more for heating energy than we do here in the snow belt of America. This is the single most reason why Europeans will never use baseboard as their heating element.