Waseem's profile - activity

Hello All,

Is it possible to specify the dimensions of window's dividers in EnergyPlus/designBuilder? I know I can specify the number of horizontal and vertical dividers and then EnergyPlus will automatically calculate the length and width of the dividers. My question is, will it be possible to specify different lengths and widths in one window frame? Please find the figure below, the top row of glazed area has different area than others. My second question is, can we specify what part of the window is openable or what part is fixed? As in the figure the top row is openable.

Thanks

Where can I find a list a EMS sensors in EnergyPlus, I know some of the sensors that can be used e.g. we can use sensor for site Outdoor Air Drybulb Temperature but I need a possible list of sensors that can be used for the IDF under study. Just to give an example We can find the possible EMS actuators by generating EDD file.

I am more interested in Daylighting sensors that can be used to compute daylighting performance matrics.

What is the best way to model Biomass boiler in EnergyPlus? Is it by using OtherFuel1 and FuelFactor objects or there is another way of doing it? If it is using FuelFactor then from where I can find all the values that needs to input in this object (e.g. C0$_2$ emission factor, CH$_4$ emission factor etc.)?

I was wondering, what is the best way to model HVAC equipment for an already existing building? Is it better to select autosizing and let EnergyPlus to do the job OR entering all the data from manufacturers' manuals? Hardsizing will also include getting the coefficients for boilers, VRF system, heat recovery elements etc.

If Autosizing and using default equations/coefficients is the answer then will it make calibration a challenging task to perform?

I am trying to model natural ventilation by using simplified method i.e. ZoneVentilation:WindandStackOpenArea object but have few queries regarding this. This object has fields of Effective angle and Height difference. The effective angle is the angle in degrees counting from the North clockwise to the opening outward normal. The value must be between 0 and 360, so if the window is on North side then this is equal to 0 (please correct me if I am wrong).

My first question is, what if the model has two windows (e.g. one on North side and one on South or east side), what will be the effective angle in that case?

My second question is regarding Height difference, it is written in the Input output reference guide that estimation of height difference in difficult for natural ventilated buildings (see chapter 16 ASHRAE Handbook of Fundamentals 2009, which may provide guidance). In HOF 2009, it is written that If one window or door represents a large fraction (approximately 90%) of the total opening area in the envelope, then the NPL (Neutral Pressure Level) is at the mid-height of that aperture, and , HNPL (Height of Neutral pressure level) equals one-half the height of the aperture.

This means for one large window this field will be the mid point of that window, right? Again, what if the model has two windows on same wall surface (lower and upper windows), then how we can calculate this height? Also, what if the model has two opposite windows (one of North and one on South side)?

If it is difficult to calculate then can we conclude that this method can only be used on natural ventilated zones that are ventilated by one large opening, which represents a large fraction of the total opening area?

P.S: I am not planning to use airflow network modelling.

Hi All, I just wanted to ask about using intersecting in sketchup plugin and stand alone measure for surface matching. When I use Sketchup plugin I get problems of generation of small surface and this does not happen while using surface matching stand a lone measure.

I remember @David Goldwasser said in one of my previously asked question that for stand alone measure if I do intend to have interior subsurfaces, OpenStudio won't find surface match unless the subsurface exists in both surfaces. So keeping this in mind e.g. if a room and corridor are two separate zones, then how this comment will fit into this situation? I have to draw door in both zones (corridor and room)?

@David Goldwasser: I would appreciate your help.

Thanks in advance.

Kindest Regards Waseem

1) I am creating the geometry of a model in Design Builder. I normally create outline blocks, create all rooms (each room considering as separate zone), circulation spaces etc and then convert them into building blocks. Does this the right approach? OR I have to create one side of the Block (set of rooms/zones) as outline block and then divide that main block into zones (rooms) by using Draw Partition tool. The first approach worked fine for me but just wondering is this the right way of doing it. By this way there are lots of blocks with one zone each. Does this the right way, I mean having many blocks with one zone each?

2) What is the quickest way to draw windows/doors on surface that is adjacent to other surface of a different zone. Do I have to use construction lines and then going into the zone and then to the surface to draw windows or there is some other way of doing it?

3) What is the best way of checking building's geometry? One can use visualise tab but I mean to check whether the surfaces are properly matched or not. I normally export it as .IDF and then open it in OpenStudio. BUT openstudio can change the geometry sometimes( which is strange). I guess this happens while translating IDF to openstudio file.

4) Finally, the wall thickness will be calculated from the materials that I assign in the Construction tab or not? If the geometry has been drawn by using Method 1 discussed above then will Design Builder consider adjacent walls of two zones (blocks) as partitions walls and will assign materials of partition wall?

Thanks

Kindest Regards

Waseem

Go to file > Export and export your model as idf file.

Hello All, Is there any way to model radiant panels (see attached picture) in ceilings by using Design builder or EnergyPlus? Can you please share your experience? Do I have to add nodes as we do for other HVAC systems? Also, these radiant panels will get hot water from a biomass boiler, can I model biomass boiler in Design Builder?

Thanks

Kindest regards

Waseem

What is the best way to model vents in EnergyPlus (e.g. Plant room's outside door, windows for preventing condensation)? Please see the figures.

Normally, in Energyplus vents are modeled using a schedule, does this schedule needs to be ON all the time? this will be uncontrolled natural ventilation or we have to input air flow rate or ach?

The issue might be because of different versions. Please check the version of IDF file exported by DesignBuilder. If you

You have to input fields in the People object to calculate/output variables e.g. activity level schedule name, work effi

Problems with Radiant Panel Heating So, I have quite a large complex school building where most of the zones are heated

I am trying to model daylighting in EnergyPlus (not OpenStudio). I am just wondering what are the Daylighting performance metrics that can be modeled in EnergyPlus for simulation time (not time steps), or if we can model for time steps then can we get some meaningful results for simulation time (weekly, daily, Run period etc.). For example we can use Daylight autonomy (DA) for analyzing daylighting, but how we can model this in EnergyPlus?

Also, what are the available EMS sensors for Daylighting?

Have you tried This Tutorial, this might help you.

Hi All, Is there any way to convert IDF to XML or vice versa? I am looking for some computer code or some IDF post processing?

Thanks

Kindest Regards

Waseem

@Jamie Bull: +1 for runner.py, nice job! Just wondering, is there a way to do this without having the E+ install directory as one's path? I have tried shutil.which() but looks like it has the same restriction?

Dear All,

I have modeled a radiant panel system and simulating for few days of winter. I have fluctuations in my room air temperature. Is this what we expect in radiant heating system meaning sharp increase in indoor air temperature and then decrease or something can be wrong? I have no internal loads (people, lighting, equipment) in this zone. Your help will be appreciated. Here is the graph for indoor air temperature, the heating set-points are 12:00 degrees till 7:00 and 17 degrees till 17:00.

Below is my ZoneHVAC:LowTemperatureRadiant:VariableFlow object.

ZoneHVAC:LowTemperatureRadiant:VariableFlow,
E.03 Radiant Radiant Floor, !- Name
RadiantSysAvailSched,    !- Availability Schedule Name
E.Block%down:0.E.03,               !- Zone Name
Roof.E.03,            !- Surface Name or Radiant Surface Group Name
0.013,                   !- Hydronic Tubing Inside Diameter {m}
autosize,                !- Hydronic Tubing Length {m}
MeanAirTemperature,      !- Temperature Control Type
autosize,                !- Maximum Hot Water Flow {m3/s}
0.E.03 Radiant Radiant Water Inlet Node,  !- Heating Water Inlet Node Name
0.E.03 Radiant Radiant Water Outlet Node,  !- Heating Water Outlet Node Name
2.0,                        !- Heating Control Throttling Range {deltaC} 
Heating Setpoints, !- Heating Control Temperature Schedule Name
,                            ! - Maximum cold water flow (m3/s)
,                            ! - Cooling water inlet node
,                            ! - Cooling water inlet node
,                            ! - Cooling water outlet node
,                            ! - Cooling control throttling range (C)
,                            ! - Cooling high control temperature schedule
,                            ! - Condensation control type
,                            ! - Condensation control dewpoint offset
,                            ! - Number of circuits
;                            ! - Circuit length (m)

@Julien Marrec: I think you had a similar problem (https://unmethours.com/question/16823...), how did you handle the situation or any thoughts about the above?

I have a building with double facades (on south and north side). In winter, the outdoor air is drawn through the southern facade and entered into the room and then exhausted through the northern facade. In summer, the flow is just from north facade(see below for winter case). I have tried to just model southern facade and main room with air loop by considering southern cavity as Plenum zone. See below in the schematic diagram.

• How should I model if I have to consider that the outdoor air is coming into the cavity and then from cavity, it is drawn into the main zone (which is not the case in figure 2 at the moment)?
• secondly, how to specify the northern facade into the air loop?
• How can I reverse the air flow (or control) depending on the season?
• and will it be possible to model Ideal HVAC system with Air loops to evaluate the performance of the building?

Is there a way to model split inverted heat pump unit (ductless) with multiple indoor units? I know the PTHP is a single zone system but what if it is connected to multiple indoor units, how to model this scenario then?