nancynanxiaodan's profile - activity

can not update MATLAB initial conditons when using BCVTB coupling EP+ and MATLAB Hi all. I am using BCVTB for linking E

can not update MATLAB initial conditons when using BCVTB coupling EP+ and MATLAB Hi all. I am using BCVTB for linking E

can not update MATLAB initial conditons when using BCVTB coupling EP+ and MATLAB Hi all. I am using BCVTB for linking E

can not update MATLAB initial conditons when using BCVTB coupling EP+ and MATLAB Hi all. I am using BCVTB for linking E

Dear All,

I am using a Air sourced heat pump for a house heat source, with ground floor(heated floor heating), first floor(water convector), and I've changed the outdoor temp always equal to Zero(constant number), and indoor thermostatsetpoint (heating) is set to 25C, simulation running period is whole Jan.

However, when I finish the simulation and looking at the results, it never reach 25C (none rooms).

1. I am wondering is there any dead band or acceptable range of the desire temperature in EP+, +- 5 degrees?
2. I've made some changes in the capacity of the heat pumps/fans, but it did not seems could increase the temp.

.

@rsunnam Many thanks! really appreciate your kind help. I could not find your email address do you mind dropping an mes

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

@rsunnam for this model, I removed all internal gains(equipment, people, lighting) except for solar gains. I've attached

@rsunnam Hi Raghu, many thanks for looking at my questions. the temp shows above is the firstfloor one room temp which u

@rsunnam Hi Raghu, many thanks for looking at my questions. the temp shows above is the firstfloor one room temp which u

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

house indoor temp could not be met Dear All, I am using a Air sourced heat pump for a house heat source, with ground fl

Hi Thierry Nouidui, many thanks for your comments. Yes, I realise that issue when I was trying to change the time step i

Connect EP+ with Matlabe via BCVTB for data exchange Hi All, Many thanks for looking at my question. I am trying to lin

Hi all,

I am using designbuilder results viewer to open the eso file, however, currently sometimes, I am facing the error named:

Error impoprting ESO file: the given key was not present in the dictionary.

I am wondering any faced this problem before, may I ask for some tips please

Thanks Nancy

Hey Jamie, I've update my questions more detail, if you could have a look and let me know your thoughts on it. thanks

Thanks Jamie, you are right, if looking at the heat flows which should be = Surface Window Heat Gain - Surface Window Heat Loss - transmitted solar radation. For example if we looking at the results, the heat flow is positive. However, what I am trying to find out is the heat loss through the window, normally can be calculated by the equation: UA(Tin-Tout). When the outdoor temp is lower than indoor, there should be losses from the window. I am trying to find out this results from E+.

Dear all,

I am trying to find out the correct variables of defining the heat loss of one building. What I am looking for are:Heat loss from the wall, roof, window, floor and infiltration/ventilation.

Up to now, after doing the searching and going through the InputOupt EP reference, what I come up with is:

Heat losses from walls, roof, ground floor = Surface Inside Face Conduction Heat Transfer Rate [W]

Heat losses from windows = Surface Window Heat Loss Rate [W]

Heat losses from infiltration = Zone infiltration Sensible Heat Loss

Heat losses from ventilation = Zone Ventilation Sensible Heat Loss

However, when I am looking at the results that the surface window heat loss rate is zero value for some time period(around 10am-3pm). I am wondering if I am looking at the right output.

one results shown below which is one window heat flow, including window heat gain, heat loss and transmitted solar radiation.

From the definition:

Surface Window Heat Gain Rate: The total heat flow to the zone from the glazing, frame and divider of an exterior window when the total heat flow is positive.

Surface Window Heat Loss Rate : The absolute value of the total heat flow through an exterior window when the total heat flow is negative.

Window heat gain = Window Heat Gain [W] - Window Heat Loss [W] - Window Transmitted Solar [W]

When calculate this window heat gain, I got positive numbers roughly around 10am-3pm. However, from the basic calculation of heat loss = UA(Tin-Tout), (the indoor temp is 18C, outdoor temp is around 2C), for this case, there should be always loss from window, not gains.

Thanks

Hi all, I am new to Eppy. went through the tutorial from the website. It seems can be used very straight forward. And my question here is about the function of SAVEAS.

I noticed that there are 3 save functions in eppy.modeleditor. one is save which works fine, and one is saveas which I tried and did not give me the expected output, same issue with savecopy.

I used following commends:

idf1.save() which save the changes I made in IDF file and save it in original idf file.

idf1.saveas("test") which didnt give me any error, however, no "test" file saved.

idf1.savecopy("test") which did not give me any error either, however, no "test" file saved.

I checked with the origin python code of eppy.modeleditor of the function save saveas savecopy. However, I have no idea, which part went wrong when I am trying to save it to a new file named test not in original file.

def saveas(self, filename, lineendings='default'):
    self.idfname = filename
    self.save(lineendings=lineendings)

def savecopy(self, filename, lineendings='default'):
    """save a copy as filename"""
    self.save(filename, lineendings=lineendings)

Thanks for your help and kind support Thanks again.

Hey @Annie Marston thanks for your reply. I used a gas boiler connect to a water heater(without heating element inside), and this simulation is on 1st Jan, which only have heating requirement.I will update my question, and I will attach the idf file.

Dear all,

Firstly, I used the calculated method to modelling the infiltration and natural ventilation in Zone air flow network section, however, I had a very high heat loss due to infiltration and ventilation, and results in the temperature significant drop in some time period.(which I've also include this results). But from the zone air system sensible heating rate, it can be seen that the heating output increased trying to make up the losses.

After I did some research, and then I decided to used scheduled infiltration and natural ventilation set up in Zone air flow section instead. however, I found out that, the zone air system sensible heating rate drops when having the infiltration and ventilation losses, where theoretically should increase to make up this loss to heat the room in designed temperature. However, the temperature is around the desired level of 19 degree.

And I tried to have the Zone Predicted Sensible Load to Setpoint Heat Transfer Rate and Baseboard total heating energy, they are given me very similar results and also drops when having the ventilation and infiltration losses.

My question here is, I didnt change anythiny for Heating system, and when having infiltration and ventilation loss, the system should increase the heating to cover that part of heat loss, however in the results showing that it reduced the heat delivered by Heating system.

I enclosed the results of one zone named dining room as an example, the results are showing in the pic.

Many thanks for your kind help.

The idf file link: IDF file with scheduled ventilation and infiltration

Results of Origin file which used calculated method of vent./infil.

Results of the file with the scheduled vent./infil.

I would like to use Eppy to change some attributes in IDF files. And when I tried I got some errors.

My code simply follows the tutorial from Eppy tutorial web page.

schedules=idf1.idfobjects['SCHEDULE:COMPACT']
occschedules=schedules[22]
print occschedules

The error I am getting here is:

raise RepresenterError("cannot represent an object: %s" % data)
yaml.representer.RepresenterError: cannot represent an object: <eppy.bunch_subclass.CheckRange object at 0x0D13B850>

And the schedule in IDF file I would like to print is showing below:

Schedule:Compact,         
Office_Reception_Occ,     !- Name
Fraction,                 !- Schedule Type Limits Name
Through: 31 Dec,          !- Field 1
For: Weekdays SummerDesignDay,    !- Field 2
Until: 07:00,             !- Field 3
0,                        !- Field 4
Until: 08:00,             !- Field 5
0.25,                     !- Field 6
Until: 09:00,             !- Field 7
0.5,                      !- Field 8
Until: 12:00,             !- Field 9
1,                        !- Field 10
Until: 14:00,             !- Field 11
0.75,                     !- Field 12
Until: 17:00,             !- Field 13
1,                        !- Field 14
Until: 18:00,             !- Field 15
0.5,                      !- Field 16
Until: 19:00,             !- Field 17
0.25,                     !- Field 18
Until: 24:00,             !- Field 19
0,                        !- Field 20
For: Weekends,            !- Field 21
Until: 24:00,             !- Field 22
0,                        !- Field 23
For: Holidays,            !- Field 24
Until: 24:00,             !- Field 25
0,                        !- Field 26
For: WinterDesignDay AllOtherDays,    !- Field 27
Until: 24:00,             !- Field 28
0;                        !- Field 29

@__AmirRoth__ Actually these slices are downloaded on-line, not mine. But, thanks for your comments :)

I have 3 different type of buildings simulation. And I have the results in eso file.

I am looking for the heat load (the heat demand/heat need to maintain the set point temperature, the heat gain from solar, people etc are not taking into account)at each time step. I used DesignBuilder, I noticed that they could do DesignDay heating calculation, but this is giving me one number of zone sensible heating (kW).

I am not sure which OUTPUT: VARIABLES OUTPUT:METERS I should looking for. I used EnergyPlus v8.3, since v8.1 they changed some of the output names, such as 'zone/sys heating rate' to 'zone air system sensible heating rate'. It caused me lot of time to figure out. Is there any doc to explain all the output variables and meters? When I type some of the output variables or meters name in google try to figure out its meaning, however, it is not a easy thing. If you guys have some tips please let me know.

What I found here is the 'Heating:EnergyTransfer' = 'Energy Transfer: Building' = total 'zone air system sensible heating rate', and from the definition of the zone air system sensible heating rate is the heating delivered by HVAC system to the zone. From my understanding, this heating rate is the heat demand minus the heat gain from solar, people etc. Please correct me if I am wrong here.

And there is 'Energy Transfer:facility', from my understanding, Facility meters contain all the energy of a fuel type. Building meters contain the sum of each zone’s energy. HVAC meters contain the energy from the air and zone HVAC system components. Plant meters contain the energy from the plant equipment. Facility = building + HVAC + Plant + exterior

I have attached the results. The red line is the energy transfer:facility, the blue line is the energy transfer:building.

Not sure which specific variables or meters I should use to represent the heat load at each time step, I believe there should be, coz the fundamental method of EnergyPlus 'heat balance' is based on the calculated heat load.

And additionally, I found out one ppt explain the output file format of EnergyPlus, and it shows that there is one CSV output file contains all data in the eso file, does anyone know how I could get this CSV file please? I want to use some of the output variables in timestep frequency (not monthly or hourly) to plot the results, such as electricity:facility, electricity generated etc.

Thanks Lyle, I've found that information, I was wondering the format of generating the SQL database file in IDF. On the other hand, I just noticed that there is a function of EP-Launch that you could group the input file, and obtain a group of output file, under this circumstance, could it be possible to extract results from multiple runs into a single file from SQL database file? Thanks Nancy

And also when I execute the .bat file, it generate a CSV file but contains nothing in it, I changed the extractfilename to the name I have from the simulation results and gave a name to csvfilename as well. Then execute the .bat file, csv file was generated but nothing in it..Just wondering where I did wrong? Thanks :)

Hey @JasonGlazer and also, when I am running the .py file, it gave me an error saying: ValueError: need more than 1 value to unpack. I am wondering that I didnt use it correctly. After the simulation, I am having the XML file and then I am trying to use epXML2CSV.py file to convert XML to CSV. probably, I am not using it correctly, may I ask some instructions for how to use epXML2CVS python file, please? Thanks

Hey Lyle, Thanks for your answer, may I ask that how you get E+ SQL output file, coz I noticed that SQL file is an optional output file format, and after the simulation did not see any files ending with '.sql'. should I change the OutputControl in IDF files to create .sql file? Thanks

Thanks Jason, It is quite a good solution. May I ask that if it is possible to obtain hourly even sub-hourly data for certain variables if I set the timesteps to 2 (half-hourly) or 6 (10mins) per hour?

Hello,

I am having an results view issue here. Wondering anyone could give me some tips, really appreciate.

The EP was called multiple times to run different simulation based on different IDF files (for example, EP was run 10 times, results in 10 Eso files and other results files. ) However, what I really interested was only some particular variables, such as the total PV generation, electricity consumption of whole building and electricity consumption of heat pumps and water heaters etc.

So what I would like to achieve is that is there a way to pick a particular result from 10 different Eso files into EXCEL or in CSV format. In order to make the results comparable, and then plot them.

I knew that xEsoView could plot the variable against the time (hourly monthly or yearly) , however, I could not physically see the exact value of the variable for a certain time period (Yes, it could be seen when you move the mouse to the points, however,it was time-consuming).

And also the results viewer from DesignBuilder could view multiple .Eso files and do the similar function of plotting or saving data as a comma separated values file for loading into a spreadsheet for further analysis, however, is there any effective way to solve this problem for a large scale of .Eso files, lets say 100?

If it was only 2 or 3 files, I could do it manually, read each value of the variable for a certain period, and then plot the graph. However, I think the results data was stored in some place, and there should be some way to read the results in more effective way to save time when dealing with lots of results.

If anyone have any suggestions and tips, I really appreciate your kind support and help here.

Thanks Nancy

Just add some points that I am looking for over 100 results in Eso files. 10 is just for an example.