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Venting opinions needed for Buderus install

Ted_9 Member Posts: 1,718
Ed, the GA124 is very quiet. You cant hear it.

If you want to go with the G124X, just line the chimney.


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  • thepassenger
    thepassenger Member Posts: 4
    sealed combustion or atmospheric

    I have learned a ton from everyone here. Thanks.

    I am in the process of replacing the entire poorly installed original steam heating system in my 1930's 2000sf home with baseboard hydronic (under going a gut renovation). Heat loss calcs say about 100k (we have 40 windows-15 in one room alone), Boston location, Icynine attic, new Harvey True-Channel storms. After extensive research I have narrowed my bolier selection down to gas fired Buderus with outdoor reset on 4 zones (132k input, 110 output). My main question has to do with venting options.

    The boiler will be in the basement. I have a masonry chimney with 2 5x8 clay lined flues. One is shot (current Burnham steam boiler vents into this), the other has been certified clean and unused. Last year I installed a Bradford White 75 gal (76,000btu) gas DHW which vents via 4" pipe into the clean flue (I wish I had waited to do indirect but the old DHW heater wasn't going to wait until this year). No evidence of condensation issues yet. The brick chimney is 24 feet tall to roof then another 4' clear. Good draft. It is interior on 3 sides-4th side is framed inside exterior wall but little insulation.

    My options are as follows:

    Installer says atmospheric venting with a G124x-32 with 5" pipe into the clean flue (sharing the DHW heater) with no need for stainless liner. Make up air would be in the form of a 8x15 louvered vent in the basement window right next to the boiler (not a fan of fan in the can). Pros of this: 1. Quiet 2. lowest cost 3. simplest mechanically. Cons: 1. Possible condensation issues with higher efficiency and outdoor reset (installer says not a problem). 2. cold make-up air being brought into basement 3. somewhat dusty conditions could mean more routine cleaning/maintainance.

    Sealed Combustion with GA-124-32. 3" stainless intake and exhaust via side wall meeting all code restrictions on direct venting. Pros: 1. fixes all cons of atmospheric 2. slightly higher efficency 3. would allow moving boiler to better location in basement for zoning/heat delivery. Cons: 1. potential noise issues from draft inducer 2. annoying steam staining outside walls/billowing past windows 3. I'm told can be more sensative to cold intake/draft issues depending on vent location.

    All comments appreciated.

    My biggest worry is condensation. Will I need to line the clay lined flue no matter what? Installer says DHW heater plus Buderus should be enough to keep flue warm but everything I've read on condensation tells me I should be skeptical with the boiler running outdoor reset. Thoughts? Also a concern is the noise from the induced draft GA-124. We live in a pin-drop quiet neighborhood and we are VERY sensative to noise issues. I know the draft inducer is inside the jacket of the GA-124 but will it be noisy at the vent outlet? How noisy?

    Thanks a million.


  • Jack_21
    Jack_21 Member Posts: 99
    Another consideration

    Given that you are doing a "gut re-model" on the house, you should look at the space the chimney is taking up. Do you want the space for something else? Will removing the chimney improve the floor plan and your comfort? Just a thought, but now is the time to look into it as it could assist you in your equipment choice.
  • RoosterBoy
    RoosterBoy Member Posts: 459

    I don't need the space from the chimney although we considered it early on.

    Thanks Ted for commenting on the sound of the GA124. Is it quiet at the exhaust as well? We had a power vented DHW heater for 2 weeks and ripped it out because the sound into the yard from the pvc vent was outrageous. I know thats a bit different but I just want to make sure we do not offend ourselves and the neighborhood. A boiler is a much bigger investment and there will be no turning back once installed.

    Should I be worried that the installer did not recommend lining? He is a great master plumber and he has a ton of conventional heating experience but he is just coming up to speed on newer systems (condensing, outdoor reset, etc). He has installed Buderus boilers but not with outdoor reset. He's eager and extremely talented and experienced. I just want to make sure he has all the proper information.

    Just so we are clear, do not let him install the atmospheric without lining-correct? Can you guess at cost to line afore mentioned chimney?

    Anyone else care to comment on some of my other concerns from initial post?

  • dconnors
    dconnors Member Posts: 215
    just a thought

    The chimney should be lined. You cant assume the hot water heater will run at the same time as the boiler. The GA series boiler is very quiet. We all have different opinions on quiet but it is alot quieter than others I have serviced in the past
  • J Sullivan
    J Sullivan Member Posts: 4

    I would caution you to go to bb after having a steam system. If I were you I would look into going with panel radiators they will give you the same radiant heat the you are used to. They work realy well with lower water temps. The lower the water temp the more radiant heat you will get.
    As far as lining the chimney I say that is a must. I insist on installing a liner on any natural vent gas appliances. If you need to use ss it will most likley to cost between $800 to $1200.
  • RoosterBoy
    RoosterBoy Member Posts: 459
    Radiant Panels

    I love the radiant panels but they have a much higher initial cost. Baseboard is about 1.5cents/btu. vs 4 cents/btu . Including heating the basement, garage and shop we have about 3000sf of heating requirements.

    As far as being "used to" the steam heat-we freeze. The old steam system was not installed properly so good ridance. I agree, panel is the way to go but is baseboard really that bad? I thought spreading the radiation across the length of the wall would give a more even heat to the room vs. the hot spots of the radiators? Our other option for same money was forced hot air with AC. We don't really need AC in our location so heating became the priority. Would you agree baseboard is better (comfort and efficiency-wise) than hot air?
  • Joe_30
    Joe_30 Member Posts: 85

    That Buderus may call for a 6" vent, and especially with the water heater. Check the mfg'r specs. But, its no problem. Get good quality 6" aluminum pipe from your supplier., in 3 foot sections. Lay a section on the kitchen floor. Put a board on it. Kneel on it with even pressure. You get an oval. The oval will fit your flue. Test this first. Use sheet metal screws to put 3 ovalized sections together, using hi temp silicon also. Push these 9 foot sections down chimney, using a clamp to keep them from getting away from you as you screw on the next. Try local mountainering store for a good guy to rope off and do the high stuff. Climbers need cash.
    Do get your boiler pro to approve the steps and eye the breach connections. He likely doesn't want to go up there either. This works. Just one sugggestion.

    dtionsget yoourp
  • RoosterBoy
    RoosterBoy Member Posts: 459

    wow, thanks Joe. I can do that myself. The roof isn't that high off the ground. I have no problem being up there. Aluminum is ok? No need for SS? The condesation that does form and run down the new alum flue-where does it go? Does it collect at the bottom? That would be bad for structural integrity at the base I would think. Suggestions for termination at the top?

    Is it better overall to keep atmospheric venting if possible? I have no problem with the induced draft design of the GA124 (as long as its quiet) but are there other caveats I'm overlooking? My bias was heading towards induced draft.

    So much to know. I love it.
  • J.C.A._3
    J.C.A._3 Member Posts: 2,981
    My testing equipment...

    is louder than the GA124 boiler in the same room. To say quiet is an understatement. WAY different than your run of the mill power vent units. My suggestion would be the Buderus concentric venting option. The cloud of condensed products of combustion may pass in front of windows beside or below it but it would be something I would not be bothered by.Outside noise is less than any fan I've heard to date.

    Use the chimney for a "romantic" fireplace or alterantive heat source if you must, but don't get rid of it. If you ever decide to sell the home, a chimney is a selling point to be sure. Think long term. Chris
  • RoosterBoy
    RoosterBoy Member Posts: 459

    The fireplace is on the other side of the house. This chimney was built for mechanical only. Its not in the way and the DHW heater is venting in it for now so I'll keep it and avoid another expense. Plus we just did beautiful lead flashing around it and repointed. When the DHW heater dies I'll do indirect which I'm setting up for even though I don't need it now.

    I think I'm going to do the induced draft although I just realized the GA124 is 123k input, 90k out. May be a little small but I'll recheck my heat loss calcs. The next larger one is 156k-overkill and a lot more pricy (but how cool would it be to have a 5' tall boiler!). I could always keep the basement a little cooler to compensate. I just want to protect my pipes which the steam system has kept from freezing indirectly.

  • Joe_30
    Joe_30 Member Posts: 85

    Ed, call 612 664 5629, joe. Maybe I can direct you to the answers.
  • MikeL_2
    MikeL_2 Member Posts: 484
    GA124 noise

    I have had a GA124/17 for 18 months. My Rolex wristwatch makes about as much noise as it does. You will never know it is running. Having had power vent DHW tanks in our old house, there is simply no contest. The thing is really, really quiet. It vents out by our front porch. Without the tell tale mist coming from the termination T, you would never know it was running on the outside either.
  • Bob Harper
    Bob Harper Member Posts: 1,030

    Run one 4" stainless liner for the orphanned water heater in one flue then a 5" stainless liner for the boiler in the other, regardless of their condition.

    They need liners for:
    -quick, stable draft
    -contain CO and other nasties
    -the codes say you do

    If you power vent out the side, it must terminate at least 4 ft above grade in addition to the clearances to windows, doors, meters, air intakes, etc. and even more if that spot is prone to snow drifts.

    The chimneys need to be protected from the elements so line then, which come with their own top plates and caps and make any repairs above the roofline.

    Anyone who certifies a chimney for anything other than needing repair is a damn fool and an idiot. You can perform a Level II inspection, which they all will flunk but not certify. Leave that to UL and the other testing labs.
  • Uni R_2
    Uni R_2 Member Posts: 589

    Baseboard with outdoor reset and continuous circulation feels much more comfortable than forced air to me.
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