Negatie results in the Water Heating model

  • mmonesterio
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03 Dec 2020 23:34 - 04 Dec 2020 23:00 #9057 by mmonesterio
Negatie results in the Water Heating model was created by mmonesterio
I'e been racking my brain to figure out why my results are coming out negative.  As you can see from the graph the results are what you would expect however all are negative. I've looked in the forum for similar posting but the only one was from '12, and I'm sure that's not it.
your assistance would be greatly appreciated.  I'e attached the model file.

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Last edit: 04 Dec 2020 23:00 by Paul Gilman.

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  • Paul Gilman
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04 Dec 2020 23:13 #9060 by Paul Gilman
Replied by Paul Gilman on topic Negatie results in the Water Heating model
Hi,

You might compare your inputs to the default cause to see what is causing the negative energy savings.

In the attached version of your file, I added a "Default" case that you can use for the comparison. The Inputs Browser (File, Inputs browser) lists of inputs that have different values between the two cases. One culprit might be the pump power, which seems out of scale with the other inputs.

Best regards,
Paul.
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  • mmonesterio
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05 Dec 2020 08:40 #9065 by mmonesterio
Replied by mmonesterio on topic Negatie results in the Water Heating model
thanks for the quick response Paul.   I did get positive numbers but only when I reduced the pump W from ~10kW to > 20W before all months went positive.
However with 240 collectors (19'x7' ea.) I need a large flow and 20W aint  going to do it. so something is still off.   I am using the collector's test flow rate to arrive at the total flow.
Best

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07 Jan 2021 18:37 #9161 by mmonesterio
Replied by mmonesterio on topic Negative results in the Water Heating model
I'e changed some of the flow parameters and am now getting results which make sense.  Thanks for your help!

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