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.

Whaddya think.. (ME)

Options
hot_rod
hot_rod Member Posts: 22,262
one could argue that the discharge of the circ, being the highest pressure point, does in fact what you described keeping the HX at the highest pressure.

I still think of any copper tube boiler as a high pressure drop HX, comparing CT to cast iron where the pressure drop is nil. Don't some of the German cast iron run without a circ pump, and only a pump downstream of the 4 way?

I know I have quieted down moaning copper tube boilers by merely upping the pressure in them by cranking up the fill valve. Sometimes an extra 5, 7, or 10 PSI static makes them happy!

Best I can do right now.

Actually in a true P/S with the expansion tank in the primary loop, and the boiler a secondary, you would "pump away" from the loop into the boiler to be truely pumping away from the PONPC. So, again you could mount the pump right onto the side of the boiler, pumping into 'er.

hot rod
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream

Comments

  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Options
    Whaddya think of my new proving ground designs...

    Comments please.

    It will be powered by a prtotype HTP mini boiler (yeah, that one...) fully condensing with a tie to a protype DHW/Buffer tank that can hopefully be operated at temps below 140 degrees (system design temp).

    It'll have a gas meter that send out a pulse every 10 cu. feet of gas, two visual flow meters, one on the closed loop and one of the DHW outlet. I will be strapping two Hobo 4 channel data loggers to it and graph what happens.

    Whaddya think?

    I've already ripped the water heater (boiler) out of my house, and I've been so busy that I haven't had a chance to get the new system installed yet. Looks like it's going to take another week dear... (She loves me, she loves me not, she loves me...)

    I'll take some pictures as it progress's.

    Oh yeah, I forgot to mention the Danfoss control logic that will data log and can be polled and operated via a telephone modem...

    Questions?

    ME
  • hot_rod
    hot_rod Member Posts: 22,262
    Options
    Tell us more

    about the prototype DHW tank, that's the part that excites me:) Is this a home built with a lot of HX surface?

    Do you have a wall hung Munchkin in hand?

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Dan Foley
    Dan Foley Member Posts: 1,258
    Options
    Looks

    Looks good, Mark. Not having installed any Munchkins, I am curious about the pump location. Why do you pump into the boiler rather than away? Is the expansion tank connected to the piping at both pump locations? -DF

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
  • Boilerpro_3
    Boilerpro_3 Member Posts: 1,231
    Options
    I bet that's a high pressure drop heat exchanger...

    that may tend to boil when water temps are high.

    Am i right?

    Boilerpro
  • Cosmo_2
    Cosmo_2 Member Posts: 43
    Options
    okay

    That must be the new wall hung Munchin I have been reading about, and I understand pumping through it because of the high pressure drop through the boiler. By connecting the expansion tank to the inlet side of each pump you use the pumping away principle, nice. I just do not understand what the arrow is pointing back towards the boiler on what seems to be the supply header running up to the purge valve and air scoop? It also looks like you are using an external tankless coil water heater for domestic hot water, this gives you a buffer tank, but why not branch off the zone after this tank? Unless I am not seeing it right, PLEASE elaborate!!!!!!



    Cosmo Valavanis

    There was an error rendering this rich post.

  • bob_25
    bob_25 Member Posts: 97
    Options


    ME, it seems to me that either pump will circulate both loops because of the compression tank connection. bob
  • paul lessard_2
    paul lessard_2 Member Posts: 192
    Options
    good eye

    Get out of that one ME!!;0
  • hot_rod
    hot_rod Member Posts: 22,262
    Options
    P/S

    ME,

    We've been piping all of our Munchkins with P/S piping due to my wanting a stable flow rate through the HX. Siggy did some new rawings for the HTP folks, which are recognizable as his by their symbols and style - very nicely drawn.

    DF & I attended a class on the new Danfoss control a few weeks ago. Can't wait to get data logging meself(G). I've got Calgary's connection number & the ability to dial in and freeze or cook em out(G).
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hot_rod
    hot_rod Member Posts: 22,262
    Options
    Most low mass

    boilers, copper tube Laars, Raypak, Lochinvar included, want you to pump into the HX, also.

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • bob_25
    bob_25 Member Posts: 97
    Options
    Paul

    is that Deadwood Spgs?
  • paul lessard_2
    paul lessard_2 Member Posts: 192
    Options
    Iron mountain

    @Glenwood spgs,They had some wirsbo 5/8 stockpiled on top of the mountain for snowmelt!!! the highest tube job ever?
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Options
    Answers....

    HR, Unfortunately, I'm not at liberty to discuss the tank quite yet. It IS a manufactured tank made by a well know organization. More when I can.

    Dan, there is a low pressure cut out switch that is a part of the safety string on the boiler. We doon't want to create ANY low pressure conditions that would cause a trip of the safety string. The principle of pumping away has more to do with pumping away from the PONPC then it does the boiler. Yes, the expansion tank is connected to the suction side of both pumps.

    Dave, it is a low mass boiler, and it will boil if flow is too low. Adding pump head pressure to the HX does alleviate the possibility of boiling. As you can see, there are two flow meters on the loops, one on the hydronics and one on the DHW. I will be able to see all and tell all...

    Cosmo, yes it is the wall hung Munchkin.

    The arrow thingy is a flow meter on the boilers common supply piping. Also one on the DHW outlet. Yes, the tank is similar to a side arm HX'er, but not quite. My system is a single loop one pipe system.

    Bob, yes you are correct, there is a small amount of forced ghost flow circulation between circuits. I limit the amount by using a 1/4" orifice where the PONPC is connected to the loops (a nickel with a 1/4" hole drilled in it, soldered in a 3/4" fitting) I'm not too worried about the ghost flow. I've done this before on commercial systems and never had a complaint.

    Paul, hope that answered your question!

    ME
  • Wayco Wayne
    Wayco Wayne Member Posts: 615
    Options
    I pump

    into the heat exchanger in my Munchkin installs. It is a high pressure loss and it has a pressure safety switch that I want to keep full pressure on. WW

    To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"
  • paul lessard_2
    paul lessard_2 Member Posts: 192
    Options
    call it a buffalo baffel!!!!!!

  • Rudy
    Rudy Member Posts: 482
    Options
    I've heard that too, hotrod

    So I do it because I like to follow the manufacturer's recommendations. Did you ever get an explanation for WHY to pump INTO the low mass boilers?

    Like BoilerPro and WaycoWayne, I can see that pumping INTO a high-pressure-drop boiler puts the boiler heat exchanger at the highest pressure in the system.

    I figure that slightly higher pressure helps keep down any flashing to steam and groaning associated with low mass/low flow HXs.

    But on the low pressure drop boilers you mention, I can't picture any significant pressure drop across those HXs, especially not when using a smaller circ.

    But since the manufacturer recommends it, I do it anyway.

    Do ya s'pose it' a turbulence thing? Just eliminating possible problem sources? Something else?
  • paul lessard_2
    paul lessard_2 Member Posts: 192
    Options
    Thanks Alan :-)

  • munchkin-man
    munchkin-man Member Posts: 247
    Options
    O Boy

    How much for each share?
  • munchkin-man
    munchkin-man Member Posts: 247
    Options
    O Boy

    How much per share?
  • paul lessard_2
    paul lessard_2 Member Posts: 192
    Options
    hey jeff!

    I met with Rick today we had mucnh fun! Thanks for the great support ! now what about vision 2? thanks paul(plumber from hell) lessard :-)
This discussion has been closed.