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Hot water generators

I'm wondering what the professional consensus is on using hot water generators (10 milllion BTU's) instead of a boiler with heat exchangers for heating large amounts of water continuously. The system I'm being quoted also includes having a 1,500 gallon insulated storage tank. My application is to provide a delta T of 140 degrees to a spinner style washer that will be cleaning food grade tank trailers.

Comments

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Define...

    Hot Water Generator please.



    What is your actual GPM demand factor?



    I assume you have 40 degree F incoming water temperatures and are looking to boost it to 180 degrees F for scald sanitization as well as scouring?



    What is the conversion efficiency of this Hot Water Generator you speak of?



    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • bjjohnson79
    bjjohnson79 Member Posts: 3
    Hot water generators

    The one I was quoted is an Armstrong Flo-Direct AFD 10,000 Hot Water Generator.



    You are correct on the water temperatures.



    We are looking at around 125 GPM at 90-95 psi.



    I think these generators are supposed to basically be 100% efficient. The exhaust temperature is cool enough to actually be vented out by pvc.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Interesting concept for sure...

    It is a direct fired unit. In other words, no isolation between the flame and the water being heated as in a conventional water heating appliance.



    I personally have zero experience with this type of system, but am aware that they have been around for quite some time (See Fulton).



    You will definitely want to keep up on the required maintenance of this equipment.



    The only thing I'd tell you to consider, is drain waste heat recovery, and Solar DHW preheat to reduce your energy consumption.



    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • Henry
    Henry Member Posts: 996
    Direct contact

    I have worked on a number of direct contact water heaters and boilers. I have even improoved efficiencies on a few projects while working in a lab. They are the best type of units for large DHW aplications. I do find the Armstrong a bit over priced. There are several companies that make similar equipment. You should look at the Sofame line. It is a bit more cost effective and is what I use in my large projects.
  • bjjohnson79
    bjjohnson79 Member Posts: 3
    Hot water generators

    Thank you for the input and advice.
This discussion has been closed.