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  1. #1
    Join Date
    Aug 2008
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    Ukraine
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    14

    Coincidence factors for different zones of commercials buildings

    Can you help me to find this coincidence factors (people, lighting, appliances) for retail, bouling, cinema, food court (cafe, restourant).
    Thank you in advance!
    Best regards, Artem.

  2. #2
    Join Date
    Dec 2002
    Location
    SouthEast NC ICW & Piedmont Foothills
    Posts
    7,635
    expound on what coincidence factors are
    It`s better to be silent and thought the fool; than speak and remove all doubt.

  3. #3
    Join Date
    Aug 2008
    Location
    Ukraine
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    14

    Arrow

    I mean percents of maximum by hours. (Sorry, English is no my native language).
    For examlpe:

    retail -9AM -0.3, 10AM - 0.4... 6PM - 1

    This mean that in 9AM in the retail area the amount of people will be 30% of maximum amount etc.

    I hope it was more understandable. Thank you

  4. #4
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    5,542
    ASHRAE Fundamentals. I found one on Ebay a few years ago. $25 i think.
    They look a several load systems. The one you explane sounds like the Bin system.
    Tracers work both ways.

  5. #5
    Join Date
    Apr 2007
    Location
    Portland, OR
    Posts
    92
    I think you are asking how to calculate load for a commercial building.

    Coincidences and percents of maximums by hours do not exist. There are no short cuts. All the different building types you mention have drastically different characteristics. You must look at local weather data, external loads, building structure types, zoning requirements, glass, exposure, orientation, internal loads (both latent and sensible), schedules, ventillation requirements, equipment type, etc., etc., etc......... Once that data is assembled, you can calculate peak loads, block loads, and zone loads. Suffice it to say this process is not quick and easy. If you are looking for rules of thumb or averages, I strongly suggest you do a 180, because that road leads only to disaster.

    If you don't have the experience or tools to do the above, you should really consider hiring an engineer. Best of luck.

  6. #6
    Join Date
    Feb 2004
    Location
    New Mexico
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    5,542
    [QUOTE=hvacguy55;4230252]I think you are asking how to calculate load for a commercial building.
    Coincidences and percents of maximums by hours do not exist. There are no short cuts.


    Not so. The BIN system was used for years until ASHRAE developed a more refined method the TETD.
    The BIN method (imagine post office boxes) involves making instantaneous energy calculations db and weighting each result by the number of hours of occurrence creating a BIN. You end up with a whole lot of bins.
    I used to have a Lennox program that used this system but as computers got faster the old DOS program began to crash. Accurate but time consuming.
    Tracers work both ways.

  7. #7
    Join Date
    Apr 2007
    Location
    Portland, OR
    Posts
    92
    hvacker:

    I think I communicated poorly. My comment was not aimed at what method is employed, but rather the importance of attention to detail.

  8. #8
    Join Date
    Aug 2008
    Location
    Ukraine
    Posts
    14
    I have ashrae foundamentals, but I hadn't found any coincidence factors there. This factors I use independent of main calculation method. I use RTS method. Can you, Hvacker, extract those data from lennox program? For cooling loads calculation I use other program - 4m fineHvac and there is own coincidence factors database, but I'm not sure those data is correct, so I made this topic for asking skilled coleagues about experience of use this method. Here I have attached those database.
    Attached Images Attached Images

  9. #9
    Join Date
    Feb 2004
    Location
    New Mexico
    Posts
    5,542
    Sorry Artem but the Lennox program is long gone. It was made in the late 1980's and after upgrading computers it wouldn't run on anything I was using.
    Like you I didn't find any coincidence factors in percent.
    There is though some tables from an example calculation in the chapter on nonresidential cooling and heating loads that have the time range over 24 hours but the numbers are in BTU's at different times but not percentages. It's under the subject TETD/TA calculation method. Might help.
    Tracers work both ways.

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