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check my math?

have a customer that another started job, got injured and couldn't do anymore. have no idea what the piping layout was going to be.

already have cast iron radiators in house, condensing boiler in basement on pallet. to be zone on each floor, hot water. wanted to double check on pipe sizing. there's piping on site, 1 1/2", 1, a little 3/4". by my calculations, all the zones should be 3/4".


  • mattmia2
    mattmia2 Member Posts: 5,978
    Doing a heat loss to figure out what you actually need out of each emitter would be good. It will help you set the reset curve later and avoid any surprises. It is very likely that the old system was oversized and even on the coldest day you can run a cooler water temp.
  • billygoat400
    billygoat400 Member Posts: 6
    I was a bit worried about the rad sizes. cust said previous owner pulled out all the steam system. previous tech supplied salvaged rads and was starting to bring in stuff for system when got badly injured. tools were all still there.

    also, most of the pipe on site is 1 or 1 1/2, only a little 3/4". no idea of what he was going to do with piping. after checking the btu demand for each floor, looks like 3/4" is sufficient for each. he also had 1 1/2" radiator valves?

    three zones, and whether I do revers return or parallel setup, going to be a number of pipes in basement ceiling.
    EBEBRATT-Ed Member Posts: 12,343

    You probably want to start piping but resist the urge. Do a heat loss, size the radiation and select the water temp and pick the pipe size and piping layout.

    If you don't follow the steps in sequence you will be in a mess. just trying to figure out what the other tech was thinking will mess you up. Start from scratch or your head will spin.

    Hope he is not hurt that bad
  • billygoat400
    billygoat400 Member Posts: 6
    Afraid I didn't sell job. asked about the load calc.

    going to do reverse return, three zone pumps. pumping away, which the manuf specs for boiler. cust has an Ultra 80 on site already. each zone will have about enough capacity in piing to add 15k-20k if needed.
  • billygoat400
    billygoat400 Member Posts: 6
    thanks for help, been awhile since been here. salesman hasn't sold any steam for several yrs. one of my favorite types to install.