[esp-r] Re: on night ventilation

Achim Geissler achim.geissler at intergga.ch
Sat Nov 10 16:32:23 GMT 2012 

Dear Koji Takemasa

as an afterthought, you seem to have two questions. One, why are the temperatures of B and C in January the same and two, what happens in the "dips" in the August run.

Based on your set points and looking at the temperatures in January more closely, it would seem quite possible that between 22:00 and 6:00 the ambient temperature never is above 18 °C. If this is the case (check!), then B and C actually are the same if I understood your model correctly.

For the second question, I would suggest using results with at least 10 ts/h (6 min intervals) and plot only the days where the strange behaviour happens. Then look at all the relevant temperatures very closely and see if there may be a logical explanation. What is the default setting? Is this maybe being used for the "strange" time intervals? Possibly compare the results with a very similar day without the strange dip.

Best
Achim



On Nov 10, 2012, at 5:18 PM, Achim Geissler <achim.geissler at intergga.ch> wrote:

> Dear Koji Takemasa
> 
> there may be a gap in your definition. As far as I am aware, the controller uses the three temperatures "low", "mid" and "high" given (18.0, 22.0 and 27.0 in your case) to set up four control intervals: Tamb < "low", "low" < Tamb < "mid", "mid" < Tamb < "high" and "high" < Tamb. The set points given are used for the first, third and fourth intervals, I think. The second interval uses the "default" setting. Sorry to say, I do not recall how/where the default is defined. Are you set up to look at the source code? I have found that this is often the most straightforward path in understanding how the controls actually work. Sorry I can't give any more specific help.
> 
> Maybe somebody else from the list can help, here?
> 
> Best
> Achim
> 
> 
> On Nov 10, 2012, at 12:51 AM, 武政 孝治 <koji_takemasa at me.com> wrote:
> 
>> Thank you for your reply. 
>> 
>> My setup was shown in the figure. It attaches.  When my setup is wrong, please let me know. 
>> 
>> Night ventilation is used from 0:00 till 6:00 at night.  It is not used from 6:00 till 22:00.  It is used from 22:00 to 0:00. 
>> 
>> The time interval of the simulation was performed in 1 minute and 1 hour. 
>> The simulation result was the same. 
>> 
> <operation.pdf>
>> 
>> On 2012/11/09, at 6:15, Achim Geissler <achim.geissler at intergga.ch> wrote:
>> 
>>> Dear Koji Takemasa
>>> 
>>> below some thoughts inline.
>>> 
>>> Best
>>> Achim
>>> 
>>> On Nov 8, 2012, at 1:16 AM, 武政 孝治 <koji_takemasa at me.com> wrote:
>>> 
>>>> Hi.
>>>> 
>>>> I have calculated the natural room temperature using night ventilation.
>>>> The size of a model is shown below. 
>>>> Height : 3m   Width : 4m   Depth : 5m
>>>> The air change rate of this model is 0.5 ac/h. 
>>>> The south window area used for ventilation is 3.5 m2 and the north window area is 1 m 2.
>>>> I attach the elevational view and sectional view of a model which were used for calculation. 
>>>> 
>>>> I calculated in the following procedures. 
>>>> 
>>>> (1)  I considered a three kinds model. 
>>>> 
>>>> A) The model which has not set up night ventilation.
>>>> B) The model which set up night ventilation.  
>>>> C) The model which  not be used it , although night  ventilation was set up.
>>>> 
>>>> I set up in the following procedures about B) and C).
>>>> 
>>>> (1) I chose network flow (menu) and defined Nodes, Components, and Connections. 
>>>> And Link nodes and zones was chosen. 
>>>> 
>>>> (2) I chose network flow from Controls. 
>>>> sensor details chose dry bulb temparature and flow actuator chose single flow connection. 
>>>> 
>>>> (3) I chose 1 day type by period data, and it defined B as follows. 
>>>> This my definition assumed that outdoor air temperature opened a window at 18 to 27 degrees at night. 
>>>> 
>>>> a 1 0.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 1.00 0.00
>>>> b 2 6.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 0.00 0.00
>>>> c 3 22.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 1.00 0.00
>>>> 
>>> It's been a while since I have used these controllers, but have you made sure that what you think is supposed to happen actually happens? What is your "default" setting (you have three temperatures that give you four ranges, but you only have three set points for the component / connection)? I find the logic in these controllers not quite easy to understand at times.
>>> 
>>> So you want the window to open, when the ambient is above 22.0 degC and below 27.0 degC?
>>> 
>>>> The definition of C) is shown below. 
>>>> 
>>>> a 1 0.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 0.00 0.00
>>>> b 2 6.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 0.00 0.00
>>>> c 3 22.00 outside ambient > low /default/mid/hi 18.00 22.00 27.00 0.00 0.00 0.00
>>>> 
>>>> (4) Annual natural room temperature was calculated. ( esp-r 11.11 GTK)
>>>> 
>>>> The room temperature graph in January and August is attached. 
>>>> 
>>>> *The followings are my questions. 
>>>> (a) The room temperature should become equal in January because the window is not opened , but it differs. 
>>> For the model without air flow network, what is your air change rate (via .opr)? Also, I expect you have some kind of "cracks" defined in the air flow network to allow it to work numerically with closed windows. So, your model with air flow network will have a (very) small air change even with closed windows, most likely.
>>> 
>>>> The room temperature of B) and C) is equal, it differs from A). 
>>> Is this a question? It would seem to suggest that the window is not opened due to control, then both cases B and C are, actually, the same. The difference to A may be due to the above issues.
>>> 
>>>> 
>>>> (b) I think that the room temperature of B in August  is right, there is an unusual value in the room temperature of C. 
>>> You mean the "caving in" of the C-curve? Have you looked at the data with a smaller time step output? At which time step setting are you simulating? Do you get "not converged" messages during the run? Have you analysed the exact hour in which the cave-in happens? Is it between 23:30 and 00:30, i.e. at day change?
>>> 
>>>> 
>>>> 
>>>> Best regards,
>>>> 
>>>> Koji Takemasa ( Dr. eng. )
>>>> 
>>>> <model.pdf>
>>>> <graph.pdf>_______________________________________________
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>>>> esp-r at lists.strath.ac.uk
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>>> 
>>> achim.geissler at intergga.ch
>>> 
>>> 
>>> 
>>> 
>>> 
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>> 
> 
> achim.geissler at intergga.ch
> 
> 
> 
> 
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