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Coil Bypass Factor problem.

asked 2014-12-19 13:15:24 -0600

Jlerazo's avatar

updated 2020-06-09 03:15:10 -0600

Hi!! I am modeling a large building, this warning presented, please anyone could said me how fix it?

************* Beginning Plant Sizing Calculations
** Warning ** In calculating the design coil UA for Coil:Cooling:Water OS:COIL:COOLING:WATER 3
**   ~~~   ** the coil bypass factor is unrealistically large;
**   ~~~   ** The initial design conditions are: Tair,in = 32.1967
**   ~~~   **                                    Wair,in = 1.759751E-002
**   ~~~   **                                    Twater,in = 7.2200
**   ~~~   **                                    Tair,out = 12.8000
**   ~~~   **                                    Wair,out = 8.500000E-003
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Can you also post how you defined this coil "Coil:cooling:water:os:coil:cooling:water 3"? Is it autosized?

Julien Marrec's avatar Julien Marrec  ( 2014-12-22 06:58:52 -0600 )edit

yes, it is autosized.

Jlerazo's avatar Jlerazo  ( 2014-12-22 08:57:13 -0600 )edit

Can you include the full definition of this object please? Also, which climate data are you using?

Julien Marrec's avatar Julien Marrec  ( 2014-12-23 03:43:16 -0600 )edit

Dear @Julien Marrec, I have the same as described here, I would appreciate it if you help me.

Mehrdad Vojdani's avatar Mehrdad Vojdani  ( 2020-05-31 07:07:07 -0600 )edit

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answered 2015-01-16 11:50:29 -0600

You might find it helpful to read the engineering reference on the coil bypass factor, here I can't link to the exact paragraph but if you search in your browser for "bypass" you will see the series of equations that are used to calculate the bypass factor. Since your cooling coil is autosized then I suggest that you scrutinize your inputs for the Sizing:Plant and Sizing:System.

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Asked: 2014-12-19 13:15:24 -0600

Seen: 2,230 times

Last updated: Jun 09 '20