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Re: [EnergyPlus_Support] ideal cooling + constVolSystem
Dear Mike,
the max iteration errors occur only if I run the simulation with air
loop system in combination with the purchased air object. When I turn
off the purchased air the System runs fine. So it seems, that the
problem is the use of both. I chanced your suggestions, but the max
iteration errors are sitll the same.
best regards
sebastian
Michael J. Witte schrieb:
> I tried turning off the air loop system and the max iteration errors went away.
> So the problem is in that part of the simulation.
>
> I see that most (or all) of the air loop components are autosized, and all but
> one of the DIRECT AIR units has a hard number for flow rate (not autosized).
> The autosizing algorithm will not see the flow rates in the DIRECT AIR objects.
> If you want to force a certain flow rate for a terminal unit, you must enter
> this in the ZONE SIZING object. In the ZONE SIZING objects, add these fields:
>
> ZONE SIZING,
>
> flow/zone, !- cooling design air flow method
> 0.7, !- cooling design air flow rate {m3/s}
>
> For each zone, specify the desired flow rate here. This should result in an
> air loop where all the flow rates are consistent and it should get rid of the
> max iteration errors.
>
> Mike
>
>
> On 20 Jun 2007 at 10:28, Sebastian Dietz wrote:
>
>
>> Hello Mike,
>> please disregard my last mail.
>> The iteration warnings still appear. I changed the priorities in the
>> ZONE EQUIPMENT LIST Objects, but it didn´t solve the Problem.
>> Furthermore I increased the number of maximum iterations with no result.
>> It would be nice, if you have another suggestion. I spent a lot of time
>> on that problem and I`m stuck.
>>
>> thanks in advance
>> sebastian
>>
>> Michael J. Witte schrieb:
>>
>>> In the ZONE EQUIPMENT LIST objects the "priority" is the order in which the
>>> equipment is simulated. Because the impact of the outside air can change the
>>> net heating or cooling load required, it should always be simualted first.
>>> So, change the heating and cooling priority for the DIRECT AIR units to be 1,
>>> and adjust the other equipment prioirities accordingly. This should solve the
>>> problem.
>>>
>>> Mike
>>>
>>>
>>> On 19 Jun 2007 at 10:08, Sebastian Dietz wrote:
>>>
>>>
>>>
>>>> Hello everybody
>>>>
>>>> currently I'm modelling a building with 10 zones. Each zone gets heated by a
>>>> basebord and is served with outside air by a constant volume System. Up to
>>>> here the system runs quite good. Now I want to model a ideal cooling System
>>>> to limit the maximal indoor temperature. Thus I used the Object
>>>> "PurchasedAir", in order to provide cool air for each Zone. But I get miximum
>>>> iterations Warnings for each timestep. I changed the values for tolerances
>>>> with no effect. Does anybody know, how to solve the problem, or is there
>>>> another easy way to model an ideal cooling system. For more information I
>>>> uploaded my "Typgebaeude.idf" file
>>>>
>>>> Thanks in advance
>>>> Sebastian
>>>>
>>>> --
>>>> Sebastian Dietz
>>>> Fraunhofer-Institut for Solare Energiesysteme ISE
>>>> Heidenhofstrasse 2, 79110 Freiburg, Germany
>>>> Phone: +49 (0) 7 61/ 45 88-51 36
>>>> Sebastian.Dietz@xxxxxxxxxxxxxxxxx
>>>> http://www.ise.fraunhofer.de
>>>> -------------------------------------------
>>>>
>>>>
>>>>
>>>> The primary EnergyPlus web site is found at:
>>>> http://www.energyplus.gov
>>>>
>>>> The group web site is:
>>>> http://groups.yahoo.com/group/EnergyPlus_Support/
>>>>
>>>> Attachments are not allowed -- please post any files to the appropriate
>>>> folder in the Files area of the Support Web Site.
>>>>
>>>> EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the
>>>> Documentation link and press the "search" button.
>>>>
>>>> Yahoo! Groups Links
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>> ========================================================
>>> Michael J. Witte, GARD Analytics, Inc.
>>> EnergyPlus Testing and Support
>>> EnergyPlus-Support@xxxxxxxx
>>>
>>>
>>>
>>>
>>>
>>>
>> --
>> Sebastian Dietz
>> Fraunhofer-Institut for Solare Energiesysteme ISE
>> Heidenhofstrasse 2, 79110 Freiburg, Germany
>> Phone: +49 (0) 7 61/ 45 88-51 36
>> Sebastian.Dietz@xxxxxxxxxxxxxxxxx
>> http://www.ise.fraunhofer.de
>> -------------------------------------------
>>
>>
>>
>> The primary EnergyPlus web site is found at:
>> http://www.energyplus.gov
>>
>> The group web site is:
>> http://groups.yahoo.com/group/EnergyPlus_Support/
>>
>> Attachments are not allowed -- please post any files to the appropriate folder
>> in the Files area of the Support Web Site.
>>
>> EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the
>> Documentation link and press the "search" button.
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>>
>
>
> ========================================================
> Michael J. Witte, GARD Analytics, Inc.
> EnergyPlus Testing and Support
> EnergyPlus-Support@xxxxxxxx
>
>
>
>
>
--
Sebastian Dietz
Fraunhofer-Institut for Solare Energiesysteme ISE
Heidenhofstrasse 2, 79110 Freiburg, Germany
Phone: +49 (0) 7 61/ 45 88-51 36
Sebastian.Dietz@xxxxxxxxxxxxxxxxx
http://www.ise.fraunhofer.de
-------------------------------------------
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