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Heat loss calc's

Shane_2
Shane_2 Member Posts: 194
Putting together an estimate for a boiler replacement, Hot water with cast iron rad's. I did a heat loss based on room size, windows, doors, etc. using Slant Fin's program. My question is, Does anyone factor in the EDR for the cast iron rads in a hot water system and how?

Also, Any reason why I shouldn't use a modcon with the cast iron emitters? (and yes I did lower design temp for heat loss)

Thank You for your time

Shane

Comments

  • That`s Excellent,

    that you`ve calculated a room by room HL, that`s the way it`s supposed to be done. Now you can take the EDR of the existing radiation to calculate the water-temp the system now requires.
    Mod-cons are a great choice for CI emitters as most are now oversized and the condensing factor can really shine!
    BTW-What unit are you considering using?

    Dave
  • bobbyg_2
    bobbyg_2 Member Posts: 139


    > Putting together an estimate for a boiler

    > replacement, Hot water with cast iron rad's. I

    > did a heat loss based on room size, windows,

    > doors, etc. using Slant Fin's program. My

    > question is, Does anyone factor in the EDR for

    > the cast iron rads in a hot water system and

    > how?

    >

    > Also, Any reason why I shouldn't use a

    > modcon with the cast iron emitters? (and yes I

    > did lower design temp for heat loss)

    >

    > Thank You

    > for your time

    >

    > Shane



    http://www.masterplumbers.com/plumbviews/2007/measuring_hot_water_radiators4.asp

    I was trying to find Dan's article "Measuring Radiators" Aprill 1999 Supply House Times.

    Only use the heat loss calc. most radiation is oversized.
  • bobbyg_2
    bobbyg_2 Member Posts: 139


    http://www.masterplumbers.com/plumbviews/2007/measuring_hot_water_radiators4.asp

    I was trying to find Dan's article "Measuring Radiators" Aprill 1999 Supply House Times.

    Only use the heat loss calc. most radiation is oversized.
  • Brad White
    Brad White Member Posts: 2,399
    Shane- come back Shane!

    Read Dave's response. Spot-on. Heat loss says "how much you need", radiator EDR says, "how low can you go" in terms of your maximum design-cold-day temperature. That last bit sets your heating curve and you can reset from that point downward.

    You may have enough radiation to put out say 75,000 BTUH using 170 degree average water temperature but if your heat loss after all insulation and improvements over the years gets you to 45,000 BTUH, you could get away with maybe 135 degree average water temperature. Properly controlled you can set this down to near room temperature on the mildest days.

    Such a deal. You did it right!
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"



    -Ernie White, my Dad
  • Shane_2
    Shane_2 Member Posts: 194


    Thank you for your reply. That's kind of what I thought. If the customer goes for it, I will be installing a Prestige boiler from Triangle Tube.
  • Ed_32
    Ed_32 Member Posts: 33
    EDR

    I believe Burnham's heating helper has info on how to determine old radiator output
This discussion has been closed.