RE: [EnergyPlus_Support] very high zone mean temperature

HI Li,

"Zone 1 Thermostat" is not a schedule, it is a Thermostat object. So no need to define it some where else in the idf file.

I attached the .err file for the no window5 model. The main serious error message in all rounds regarding Rslab is the repeated "shut down due to reaching condensation temperature". Which I don't know why it is happening while the space temperature is up to 35 degree. On the other hand, surface temperatures for the Rslab it self is perfectly matching the space set point. On the other hand, this error is not happening in zones with very high temperatures, e.g. Z7, and after all it should only affect the system during cooling period only. Shutting down during heating period should simply help reducing spaces temperature.

Thanks again

Alaa Kandil
Email: aakandil@ucalgary.ca,alaak1974@yahoo.com
mailing address :304 Jackson PL, NW,Calgary,t3b2v3
Cell No.:+1-403-818-5447
Phone No.:+1-403-282-9497

--- On Wed, 7/1/09, YuanLu êª×¿ Li <yli006@hotmail.com> wrote:

From: YuanLu êª×¿ Li <yli006@hotmail.com>
Subject: RE: [EnergyPlus_Support] very high zone mean temperature
To: "Linda" <energyplus_support@yahoogroups.com>
Date: Wednesday, July 1, 2009, 6:00 PM

Hi, Alaa Kandil

If you would let me have the IDF file with the normal window entries, I will try running it in order to reduce the warnings in the error file, so that the other errors may be viewed easily.

I now realiase that some names such as MeanAirTemperature are default name in the object.    As such, they need not be defined again in the IDF.

If heating and cooling can come on together, then they may also be turned off together, when the schedules are not correctly interpreted by the Energy Plus. This is the reason why I would like to reduce the number of warnings in the error file first, and then trace the problem.

Zone 1 Thermostat is a schedule name, therefore it only appeared once.

I am still learning by try and error, and reading the IO manual.

Dr. Li

To: energyplus_support@ yahoogroups. com; EnergyPlus_Support@ yahoogroups. com
From: alaak1974@yahoo. com
Date: Tue, 30 Jun 2009 17:38:48 -0700
Subject: RE: [EnergyPlus_ Support] very high zone mean temperature

--- On Tue, 6/30/09, YuanLu êª×¿ Li <yli006@hotmail. com> wrote:

" I noticed that:
MeanAirTemperature    was in the Z1 RSlab object but the control type of the same name was not found in the idf file."
I think we need to define the RSlab control type only in the RSlab object and radiant heating and cooling set point with the throttling range define the rest.

"Zone 1 Thermostat was Defined and not used"

Can you please explain more why it is not used?.

"Dual band type used the same names for the set points, but with different values for different types, and the values did not have a dead band."
Dual band was used only during May and September, and they do have dead band (18-26, 20-22, 18-26). However the high zone temperatures occurred even during moths with pure heating, e.g. January.

"I may have picked up the wrong objects. I think, the plant side did not have a season dependent available schedule. Therefore, heating and cooling may be on at the same time."
Plant loops are controlled by heating and cooling load operation schemes. So, as soon as the thermostat type is heating only or cooling only for all the zones, heating and cooling plants shouldn't work at the same time. This could only happen during the dual set point control periods (May and September)

"Most of the 107 warnings are on the Window5 data, which I do not have much experience in using."
This is not a big issue as soon as I have the same material for all corners of the window frame. I also ran the model with normal construction window and results were almost the same.

Your plotted results seem to show that the system is under sized and the zone temperature is floowing the solar load..
Do you mean under sized for cooling (which why we have high temperatures) ? ..but how can we explain the low zone air temperatures (around 15 degree) when I turned the radiant slab off?

Sorry, that I cannot solve the problems quickly.

Dr. Li

Thanks a lot for your effort

To: energyplus-support@ gard.com; EnergyPlus_Support@ yahoogroups. com
From: alaak1974@yahoo. com
Date: Mon, 29 Jun 2009 09:32:10 -0700
Subject: [EnergyPlus_ Support] very high zone mean temperature

Hi

I am simulating a school building that has radiant slabs and a VAV displacement ventilation air system. I am facing a very high zone mean air temperatures. .. away above set points.

Can anyone help me with that? I attached a summary of the results as well as the idf file and any required data files.

Thanks in advance

Alaa Kandil
Email: aakandil@ucalgary. ca,alaak1974@ yahoo.com
mailing address :304 Jackson PL, NW,Calgary,t3b2v3
Cell No.:+1-403-818- 5447
Phone No.:+1-403-282- 9497

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