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/.
Click here to Find a Contractor in your area.

DHW- direct fired or indirect?

Options
NYplumber
NYplumber Member Posts: 503
edited January 2017 in THE MAIN WALL
Hi,

I have a job that requires roughly 2.6mmbh for the showers. The current setup of tankless is undersized and in need of extensive repair.
The options are direct fired heaters with storage, or indirect (ie turbomax which i have ised with great success).
There is room for sidewall venting, however there is a chimney stack that is sufficiently sized. The intake air must be taken from outside (sealed combustion) due to the mechanical room being in close proximity to the pool chemicals.

Looking for pros and cons of each setup as well as manufactures of direct fired.

Thanks,
M
:NYplumber:

Comments

  • Zman
    Zman Member Posts: 7,569
    Options
    Is the 2.6mmbtu your estimate for on demand?

    Generally when you add storage you can reduce the output of the plant. Most manufactures a simple chart or an online calculator that shows the relationship. By adding storage you create a buffer to help bridge over spikes in demand so less boiler firepower is needed.

    I see some real advantages to the turbo max setup especially when the DHW system is part of a heating plant. The fact that it does not store DHW is a bonus from an anti legionella point of view.

    I would start by getting a fixture count for the building rather than using an estimate based on previously installed systems. Most manufactures have software or charts to assist with sizing.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • hot_rod
    hot_rod Member Posts: 22,157
    Options
    here is a good resource
    http://lochspec.lochinvar.com/default.aspx?&PID=60956
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • NYplumber
    NYplumber Member Posts: 503
    Options
    > @Zman said:
    > Is the 2.6mmbtu your estimate for on demand?
    >
    > Generally when you add storage you can reduce the output of the plant. Most manufactures a simple chart or an online calculator that shows the relationship. By adding storage you create a buffer to help bridge over spikes in demand so less boiler firepower is needed.
    >
    > I see some real advantages to the turbo max setup especially when the DHW system is part of a heating plant. The fact that it does not store DHW is a bonus from an anti legionella point of view.
    >
    > I would start by getting a fixture count for the building rather than using an estimate based on previously installed systems. Most manufactures have software or charts to assist with sizing.

    Thanks for commenting Zman. The calculated numbers are actual based off the showers. The building needs roughly 5000 gph on an 80 degree rise.
    :NYplumber:
  • NYplumber
    NYplumber Member Posts: 503
    Options
    > @hot rod said:
    > here is a good resource
    > http://lochspec.lochinvar.com/default.aspx?&PID=60956

    Thanks HR. I will take a look.
    :NYplumber:

Categories