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two-pipe or loop???

Timco Member Posts: 3,026
Apartments are 950sq', 500sq', 850sq', 750sq'. Large home converted to 4-plex in 1935 or so. Bought my Crown atmospheric boiler today. 140k btu. (double brick ext walls, not much insul in attic, all original single pane windows...3 large ones, several smaller ones. No storm windows. Was (am) considering grundfos 15-42's, but boiler came with 007. Should circ fine, but I like the grund's.

Thanks for the opinion....


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Just a guy running some pipes.


  • Timco
    Timco Member Posts: 3,026

    So here I am finally getting to this boiler swap in my 4-plex. I am splitting the old system into 4 zones so each unit has it's own t-stat & circ. Given that I am going to use 1" h-pex & 4 007's to re-run the new zones, should I go loop or 2-pipe design? 1 large, 3 med & 1 small rad per unit. Also, what is the easiest way to cut out all the old 2" & 11/2" piping not being re-used. People live in this unit where I will be re-piping in the basement.



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    Just a guy running some pipes.
  • Empire_2
    Empire_2 Member Posts: 2,343

    I'll take the last first and say sawz-all. Your total output of the rad's cannot be to much I suspect,....may be 600 sq/ft per apt??? just guessing. I haven't looked at the pump curve yet, but should be OK as far as pumps go, but what equipment are you using? Mod Con/ or other? I'm just thinking here and I would go loop since the apts are relatively small and should take no time at all for the boiler to recover...whether it 1 calling or all 4 zones. Just my thoughts as you know, but that's what I would do.

    Mike T.
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