Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Venting of mid efficiency via chimney

Hello,

The current water heater is a 20yo gas fired tank atmospheric vented into a masonry chimney with single wall 26ga 3" pipe. Its making those wonderful gurgling sounds whenever a faucet is opened.
I'm looking to replace it with something with a higher efficiency but not necessarily a condensing unit.
Maybe a mid efficiency tank or tankless.
I looked at the Rheem EcoSense direct vent but the venting accessories are all double wall steel and I'm assuming that its a coaxial setup where supply air is brought in via that piping. I wouldn't be able to support the piping every 4' as required in the instruction so that's a no go.
Any suggestions?
Mid or high efficiency, masonry chimney vented, tank or tankless.

Comments

  • SWEISWEI Member Posts: 7,356
    Any utility rebates available? How hard is the water, and what kind of chloride levels?
  • StentyStenty Member Posts: 74
    Municipal water. There is very little scale issues and it tastes pretty good, no sense of chlorine in the taste of it.
  • StentyStenty Member Posts: 74
    The Noritz NR981-SV-NG has single wall venting.
  • SWEISWEI Member Posts: 7,356
    I would suggest a condensing TWH with PP flexible venting. Installs in the existing chimney in about an hour, costs far less than stainless vent material.
  • StentyStenty Member Posts: 74
    Would the upfront costs of a condensing unit outweigh the cost of SS vents?
    Would a condensing unit also require piping for outside air?
  • SWEISWEI Member Posts: 7,356
    Stenty said:

    Would the upfront costs of a condensing unit outweigh the cost of SS vents?

    By far, IME.
    Would a condensing unit also require piping for outside air?
    Generally yes, but depending on the TWH manufacturer and the leakiness of the basement -- maybe not.
  • SteamheadSteamhead Member Posts: 13,998
    What other units are venting into that chimney?
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
  • StentyStenty Member Posts: 74
    No other appliances.
  • SteamheadSteamhead Member Posts: 13,998
    That would let you do pretty much whatever you want, within the limits of safety. It's possible, as others have stated, to use the chimney as a chase for a concentric venting system. You want to avoid venting an appliance directly into the chimney that is so small it doesn't create proper draft, allows the exhaust gases to condense in the chimney, or both.

    Whatever you do, avoid the use of PVC pipe for venting combustion appliances. Polypropylene (PP) or stainless steel are the way to go- they are UL listed for venting combustion appliances whereas PVC/CPVC is not. Yes, we see a lot of PVC combustion venting, but that doesn't mean it's the right way to go.
    All Steamed Up, Inc.
    "Reducing our country's energy consumption, one system at a time"
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Baltimore, MD (USA) and consulting anywhere.
    https://heatinghelp.com/find-a-contractor/detail/all-steamed-up-inc
    SWEI
  • StentyStenty Member Posts: 74
    The Noritz NR981-SV is listed as Category III.
    The Polypro Duravent pipe is listed a Category II and IV. Does that qualify it for Category III ? I don't know enough about the categories.
    I once bought aluminum flue liner from my supply house for a gas boiler
  • SWEISWEI Member Posts: 7,356
    Stenty said:

    The Noritz NR981-SV is listed as Category III.
    The Polypro Duravent pipe is listed a Category II and IV. Does that qualify it for Category III ?

    No.

    Takagi/AO Smith and Rinnai both use Category IV on their condensing TWH models. I'm sure there are others.
  • StentyStenty Member Posts: 74
    The Noritz NR981-SV is non-condensing.

    Category II
    An appliance that operates with negative static pressure in the vent and a temperature that is low enough to cause excessive condensation in the vent.

    Category III
    An appliance that operates with positive static pressure in the vent and a temperature that is high enough to avoid condensation in vent.

    Category IV
    An appliance that operates with positive static pressure in the vent and a temperature that is low enough to
    cause excessive condensation in the vent.
  • SWEISWEI Member Posts: 7,356
    Right, so it needs stainless venting.
  • ChrisJChrisJ Member Posts: 11,263
    What about lining the chimney with the appropriate size liner and installing one of these guys?

    http://www.supplyhouse.com/Bradford-White-RG2D50S6N-50-Gallon-40000-BTU-Defender-Safety-System-Damper-Atmos-Vent-High-EF-Energy-Saver-Residential-Water-Heater-Nat-Gas


    I'm suggesting this due to simplicity and silence. A standard atmospheric would be the cheapest, but I hate the pilot and all of that heat always going up the flue.


    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • 4Johnpipe4Johnpipe Member Posts: 479
    LANGAN'S PLUMBING & HEATING LLC
    Considerate People, Considerate Service, Consider It Done!
    732-751-1560
    email: [email protected]
    www.langansplumbing.com
Sign In or Register to comment.

Welcome

It looks like you're new here. If you want to get involved, click one of these buttons!