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Fire Tube Boilers quietness

witold
witold Member Posts: 7
I have a 200,000 BTU input condensing boiler (Laars CB 200) which is nearly 10 years old. I would like to replace it with a new one having a Fire Tube heat exchanger. I am specifically considering Lochinvar Knight, HTP (also a Westinghouse brand probably made by HTP) and possibly Lennox. I would like the boiler to be more quiet than the present one. The current boiler is vented using 4" PVC pipes, and I believe that the forced air fan makes most of the noise. I made the calculation of heat delivery (not heat loss), using the data of my installed Runtal radiators. I believe that the sizing of the boiler is correct.

I read somewhere, that a detail of how the boiler is fired is important. Some modulating boilers supposedly fire at 100% and them modulate down, while others fire at 20% and modulate up. The noise is supposedly related to firing rate. I would therefore prefer, absent other considerations, to have one which fires initially at low rate and modulates up.

I also noticed, that all the boilers I am considering have either 2" or 3" venting. Does the size of the venting tubes affect the level of noise, and by how much? I would rather upsize the size of the vent tubes, if that makes a significant noise difference.

My second question is, how friendly are the above-named companies with supporting homeowners directly. I am a pretty sophisticated engineer and perfectly capable of maintaining my boiler. Should some minor trouble develop (e.g. pump failure), I am perfectly capable of replacing it myself (been there, done that). Also parts availability directly is a consideration.

Right now, Lochivar Knight is my front runner, with HTP close second. I live in Chicago area.

Anyone has any experience with these boilers and can provide the answers?

Comments

  • Rich_49
    Rich_49 Member Posts: 2,628
    The Westinghouse certainly is an HTP product . Lots of them sold through Menards .

    Does the boiler make your DHW also ? Try to identify one of the Ft boilers that does not require primary Secondary piping . This will insure the highest levels of ACTUAL efficiency . There are a few of them but the best at present is certainly the UFT by HTP accepting flows down to 1 GPM . Only problem is right now the largest UFT is 140,000 . Are you positive of your heat loss ? Heat delivered is not very accurate , although you usedf x amount of fuel it is almost impossible to determine how much of that heat was actually delivered based on a number of factors and the actual running efficiency of the boiler and SYSTEM most importantly .

    HTP's factory and tech support is the best I have ever had the pleasure to work with and their dedication to develope and produce equipment that avoids many of the problems others suffer from due to complexity and BS is admirable . A Sole Propreitor also makes things much better .
    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
  • witold
    witold Member Posts: 7
    Rich,

    Yes, my boiler is used for hot water, but it is "indirect" hot water (I have an 80 gallon tank with a cupro-nickel coil in it.). I intend to keep it. My piping currently is in the primary-secondary configuration, and I thought to keep it that way too. Extracting every last drop of efficiency is not my goal. By going with a modulating condensing boiler with large number of zones and good controls I should be efficient enough.

    Thanks for the tip of Westinghouse being sold by Menards. I was not aware of that. I was aware of UFT and liked it. Somewhere I saw a published spec by Westinghouse having those boilers going all the way to 200,000 BTU. So, perhaps I could wait a month or two. This boiler has a wider range of modulation, than 5:1 all the others have.
  • Zman
    Zman Member Posts: 7,013
    You need to perform a heat loss calc on the house.
    The radiation number really only tells you how much you can overheat the house if you put in too large a boiler. Unless you are planning on opening a "hot yoga" studio, this is not a good plan.
    Only a heat loss calc will tell you the size you need.
    Unless you are in an 8,000 to 10,000 square foot cottage, the existing boiler is too big. The good news is that all that extra radiation will allow you to run low water temps and increase the boiler efficiency.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    SWEIRich_49kcoppGordy
  • bmwpowere36m3
    bmwpowere36m3 Member Posts: 512
    edited December 2015
    My Loch WHN fires at 58% initially for a few seconds and then either modulates up/down depending on load and/or ramp delay settings. At 100% fire, all you hear is a medium-pitched whine of the fan…. otherwise at lower fire rates the fan is relatively quite.

    The WHN 55 I piped with 2" CPVC (sch 80)/ 2" PVC (sch 40) for exhaust/intake respectively, per the manual. The manual spells it out… It shows 2 sizes allowable for each boiler size and their corresponding MIN and MAX lengths. Don't forget each fitting (90/45) adds to the length (it listed in the manual as well).
  • Gordy
    Gordy Member Posts: 9,514
    edited December 2015
    With 10:1 TDR, and 8k low end modulation over sizing becomes a non issue with the UFT. The whn 55 still only low ends at 11k. Enough said.

    Skip the westing house all though an HTP by product it's lowest size offering is 140k unit with 5:1 still probably to big especially the low end.

    Heat loss heat loss first.
    Rich_49
  • Brewbeer
    Brewbeer Member Posts: 616
    I have a new Loch WHN 055. At 20% fire, the system circ makes more noise than the boiler. The boiler is so quiet at 20% fire that you need to look at the display screen to see if it is running or in standby mode.

    I echo the comments of others about doing an accurate heat loss calc for the building. 200,000 BTUs per hour is HUGE and not many single family houses have such a high rate of heat loss, especially anything built in the last 40 years.
    Hydronics inspired homeowner with self-designed high efficiency low temperature baseboard system and professionally installed mod-con boiler with indirect DHW. My system design thread: http://forum.heatinghelp.com/discussion/154385
    System Photo: https://us.v-cdn.net/5021738/uploads/FileUpload/79/451e1f19a1e5b345e0951fbe1ff6ca.jpg
  • Rich_49
    Rich_49 Member Posts: 2,628
    @witold

    Just to give a perspective . I am ready to start 2 projects simultaneously on large homes . Neither is particularly very tight and as large houses go they are both pigs . One of them will have a heat loss of 190,000 for an area totalling 10,000 sq ft and the other ( better) is 112,000 for 9,000 sq ft .

    You really should have a heat loss calc performed and while you're at it have someone perform a blower door to determine how many air changes per hour so you can nail that down . If the number sucks you can tighten it up a bit and do yourself a huge favor .
    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
    kcoppGordySWEIKC_Jones
  • witold
    witold Member Posts: 7
    @everyone
    I appreciate all the comments very much.

    Regarding boiler sizing and house heat loss: I understand your good advice: uderstand your actual heat loss. My house
    was built in 1925. It is a standard construction wood frame and brick exterior house with no insulation in the walls. It has 3 levels plus basement. The total is 3,700 sq ft above ground and 1,500 sq ft of basement. When temperatures in Chicago dip to -20 F and there is wind, the current 200K condensing boiler is going full time without any cycling, while the temperature on the first floor is 55 F and I can hear wind whistling in the window cracks.
    There are a lot of windows on the first floor (they are old, quite significant architecturally, very tall, leaving little space beneath for Runtal radiators), and would be extremely expensive o replace, if exact reproduction was requested. I made some efforts over the years (I lived in this house for the last 28 years)
    to improve this situation, but was only partially successful.
    One year my wife reported that water in dogs bowl has frozen the kitchen, because it was positioned near an air leak! The dog looked quite perplexed! (I plugged that leak, and quite a few others since then, but there are many remaining.) Before I put in a [predecessor to my current boiler (a Heatmaker CB 200)], I had heat loss calculations done as well as house air tightness evaluated by an engineer who put a blower in one of my doors and measured pressure drop. The result of that last experiment was worst he has ever experienced, so he told me I must have a hole of 1 yard X 1 yard somewhere in the house.
    He decided to not charge me for the result, because the pressure drop was not measurable. The engineer who made heat loss calculations told me, that because of the lack of air tightness of the house his calculations are quite academic, and I should go by the installed radiation capacity for each room as a guide, rather than his calculated values, and do everything possible to improve the air tightness of the house. This was all done when I was replacing old cast iron humongous radiators by new Runtal ones, quite a bit more compact. I put a Runtal under each window on the upper levels and along the entire perimeter of the house in the basement.

    So yes, it is a horror story, and I learned to live with it. Fortunately, the temperature drops that low only for couple of days per year, so it is not a huge issue - we keep to the upper floors on those days, which have much fewer and smaller windows, and the temperatures are comfortable there.

    Regarding quietness: my boiler room in the basement is directly below the family room, where we spend a lot of time and watch television, etc. I can hear my current boiler there. It is not boo noticeable, but I would prefer the new boiler to be quieter. To that end, I would appreciate comparisons between the boilers I have mentioned.

    I am considering converting a 16 x 20 screened porch into a sun room, with a lot of window surface along 3 walls and have underfloor radiant heating there. So I do not mind some spare capacity in the boiler.

    I intend to use synchronizing zone controllers (probably by Tekmar), so that boiler short cycling is minimized (and possibly eliminated altogether). A UFT by HTP with 10:1 modualation would be helpful, but I would really like to have 200K capacity. However, given pricing of these boilers being in large part proportional to their capacity, perhaps I should consider putting in two UFT, each sized to 100K. That way, I would effectively have 20:1 modulation and redundancy. I appreciate redundancy, as I did live through a boiler failure twice in this house, and it always happens on the coldest day of the year. I own a lot of electric heaters as a result and have a supply of wood for the fireplace always on hand.

    Pardon for being so long winded and taking so much of your time. Hope you got some entertainment form this! Merry Xmas and Happy New Year!
  • bmwpowere36m3
    bmwpowere36m3 Member Posts: 512
    Sounds like money better spent to "seal" the house up... either replacing the windows, interior/exterior storms or some form of window treatment.

    That said, I can't hear my WHN55 upstairs (directly above it). I can only hear the system pump faintly and some water flow-noise thru the radiator. Then again a 200k boiler needs a lot more airflow... not sure if they increase the size of the blower and/or RPM. I wouldn't be surprised if it more noisey as well.
  • witold
    witold Member Posts: 7
    I do agree that money is better spent on "sealing" the house, but my current boiler is on it's last legs, and I am afraid that I will experience another failure on the coldest day of the year, so I have to replace it. I may survive this winter, or may not. So, I am trying to at least get the best boiler I can, which can work for the present house demands, as well as the future ones. I did identify a form of storm windows I could use, which will not detract form the architecture of the present windows. That should help a lot on the first floor. This will be done as next summer project. The cost of replacing the original windows is $$$$, not feasible now.
  • Rich_49
    Rich_49 Member Posts: 2,628
    You'll need to do a radiation survey now and determine what water temps you can use with your installed radiation . Room heat loss should be reconciled with the radiators installed in that room . This is how you'll determine the AWT needed in each and how to set the reset curve .

    I can tell you this with near certainty , 2 UFTs will be roughly the same first cost as either of the 199,000 BTUh products mentioned prior .
    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
  • BobC
    BobC Member Posts: 5,232
    I have a smaller older house that looses heat at a good rate, the winters tend to be cold and windy. If your house is balloon framed like mine is the best money you can spend is ion air sealing to lower the infiltration rate. The windows are one area to look at but the other is the open wall chases that run from the sill up to that attic, if you can seal those off you should be able to make a dent in that air infiltration and that will make a difference in the heat loss.

    I am conversant with steam so I'll leave it to those more familiar with condensing boilers to comment on the best replacement option.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • witold
    witold Member Posts: 7
    @BobC
    I really have those open wall chases going form the foundation wall all the way to the attic. I thought they are required for air circulation, so there is no condensation trapped there.
    Do you mean, I shall try to fill them up with something?

    I am not going to have any foam-type product containing any chemicals injected - too much of a health hazard. My wife would divorce me if I did that. My walls are plaster, so I could only drill small holes and repair them subsequently (after a material is blown-in through them into the spaces). Taking down drywall to put in insulation is not an option.

    It passed my mind to fill those spaces with some sort of natural material, like particles of cork, but not sure if I can find somebody who actually is equipped to use such a material for blown-in installation.
  • BobC
    BobC Member Posts: 5,232
    Just stopping the air movement in the wall cavity will go a long way to cutting the heat loss. Those chases should be sealed off so air can't just race through them. Having insulation in them would be best for heat loss but stopping the air movement would help a lot.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Gordy
    Gordy Member Posts: 9,514
    Ballon framing.
  • SWEI
    SWEI Member Posts: 7,356
    Dense-packed cellulose is nontoxic, breathes, and can be installed from the attic. It will not explode the walls, does not outgas, and will seal air leaks at the same time.
    GordyRich_49
  • tim smith
    tim smith Member Posts: 2,403
    I am a fan of the Lochinvar whn boiler. The 199 is a good size for a lot of our needs. I would agree if you can fit it in the budget I would do twin boilers. Then you get 10:1 turn down. On upper firing rates you will hear some fan noise at vent terminations, especially on combustion air inlet but not that often. Overall they have been bullet proof for last 5 yrs for us. Good luck
  • witold
    witold Member Posts: 7
    @SWEI
    Thanks for the blown-in cellulose suggestion. I have it in the attic between the rafters. Has been a problem, when the roof started leaking. Just had a new roof installed. Hopefully the water leaks are gone, but I am concerned about condensation, which may be a separate problem. I just read an article which said that blown in insulation is not a good idea for roofs. I have been prejudiced against it, because of the said problems with the roof.
  • witold
    witold Member Posts: 7
    @tim smith
    Thanks for the solid endorsement of Loch's WHN quietness and reliability. Sounds like the quietness is a non-issue with those boilers and that is why there is not much discussion of it.
  • Gordy
    Gordy Member Posts: 9,514
    witold said:

    @SWEI
    Thanks for the blown-in cellulose suggestion. I have it in the attic between the rafters. Has been a problem, when the roof started leaking. Just had a new roof installed. Hopefully the water leaks are gone, but I am concerned about condensation, which may be a separate problem. I just read an article which said that blown in insulation is not a good idea for roofs. I have been prejudiced against it, because of the said problems with the roof.


    You have to understand what causes the condensation process with in a wall cavity.

    With no insulation condensation will still occur. It's just able to dry.

    With dense pack cellulose the warm moist air stays away from the cold exterior surface minimizing the dew point in the wall cavity. Fiberglass batts tend to create convection with in a wall cavity.
    SWEIRich_49
  • vaporvac
    vaporvac Member Posts: 1,520
    edited December 2015
    It may be enough to seal and insulate your rim joists in the basement to prevent the chimney affect of balloon framing. I'd start there and see where that gets you. Also, please don't replace your windows. If you're at all handy you can make very attractive interior storms that work great and achieve equal R-values with no environmental or aesthetic downside. You can also purhase them made-to-measure, but it's more expensive obviously: http://www.indowwindows.com/
    Exterior storms are also an option. Caulking around the window frame makes a huge difference and Seal'n'Peel is a wonderful, non-damaging product for air infiltraion on the sashes. I vapor-barriered and insulated my attic knee walls. which also helped ALOT! Your house will be silent by comparison if you make these small changes.
    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
    If you plan to install blown cellulose (highly recommended with balloon framing IME), you want to carry it all the way to the foundation. We typically cover the space above the foundation and below the first floor using perforated house wrap (lots of staples, sometimes a 1x over that.) The cellulose can then fill the entire cavity all the way down. Make sure you take care of any electrical re-work before you insulate.
  • Jason_13
    Jason_13 Member Posts: 299
    Fire tube or water tube the noise levels are the same. TDR are important. Limiting the input to match central heat and domestic hw loads are important. I feel multiple boilers should always be used as opposed to a single boiler should be chosen.
    How many heating zones do you have? What size IWH?
  • ced48
    ced48 Member Posts: 469
    When located in a living space, at full fire, the fan noise can be quit distracting.
  • Canucker
    Canucker Member Posts: 703
    I'm definitely interested in this topic. Someday my raypak will die and I want something quiet as it's in the same room as my home theatre and I don't want anything louder than it is. I wonder if the manufacturers have a decibel reading for different firing rates?
    You can have it good, fast or cheap. Pick two