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2022-08-22 15:38:43 -0500 | marked best answer | ACH based air system design I need to model a hospital, which has some strict requirements for the air changes per hour. I want the air system (for the moment the "ideal loads" one, in future a full mechanical ventilation system) to supply air in order to respect thermostats temperatures, air changes per hour and if possible, also the humidity comfort levels. Is this possible? I have read a couple of answered question but I could not find exactly what I need, I have also tryed to discover it by myself, but I cannot find anything useful. |
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2020-10-02 01:43:02 -0500 | marked best answer | Problem with fancoil modeling I have consulted the InputOutput guide and the "search" function but with poor results about how to model a cooling only fancoil in openstudio. At the moment I am using a simple air loop with a cooling coil and a fan, with a single duct uncontrolled diffuser. The setpoint is a simple scheduled setpoint manager. See the image below for more clarity. I wonder if this configuration can be used to mimick a cooling only fancoil. The major incongruence is that the fancoil recirculates and cools the indoor air (the ach are assured with a VAV system) while with this configuration it will take fresh air from outdoor. I have also tryed to use a 4pipes fancoil, but apparently I cannot place it anywhere in my loop (both demand or supply side nodes). I have read that the 4 pipes configuration can be used to simulate a 2pipes configuration, setting the availability schedules accordingly. I have also tryed to simulate without the outdoor air intake, but the simulation fails with the following error: "IP: IDF line~3526 Object=CONTROLLER:MECHANICAL VENTILATION, name=CONTROLLER MECHANICAL VENTILATION 1, Required Field=[Zone 1 Name] was blank" Thanks to anyone that will contribute Federico edit: I have set the coil detail as follow but I encounter error The design coil load is zero for Coil:Heating:Water FAN COIL WITH VAR FAN CONST FLUID FLOW - HEATING COIL * ~~~ * An autosize value for UA cannot be calculated * ~~~ * Input a value for UA, change the heating design day, or raise * ~~~ * the zone heating design supply air temperature |
2020-08-13 08:41:26 -0500 | marked best answer | Correct choice of Set point managers Hello everybody, I am fairly new to the world of energy simulation but I was charged with a hard task. Basically I need to simulate an hospital building (15 floor total, 53.000 m^2 surface). I have created the 3d model with sketchup and assigned a very simple thermal zoning (1 floor= 1 zone). I have also begun to connect the HVAC systems, which are (for the moment) only 2 VAV with reheat. I modified the two system to have, on the hot water side loop, district heating as heat source. The chilled water loop is made by an absoption chiller linked to a simple condensing tower. The simulation runs smoothly except for some shading surface warnings (which I will adress later). The problem is that I have a lot of unmet hours during both cooling and heating. I think this could depend from the setpoint manager I have chosen. I selected a min max with deadband for both the VAV system, slightly modifying the standard schedules automatically created by openstudio. Can anybody help me adress the problem? I am sorry for my poor english. Ps: what files shall I attach to the message to help adress the problem? Thanks |
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2019-12-21 16:18:16 -0500 | asked a question | Using measured horizontal irradiation as input for PV production Using measured horizontal irradiation as input for PV production Dear all, I am trying to make a comparison between the |
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2019-07-25 10:29:43 -0500 | asked a question | Coil:Cooling:DX:SingleSpeed how to check condenser air inlet temperature Coil:Cooling:DX:SingleSpeed how to check condenser air inlet temperature I would like to check some results I have obtai |
2019-07-19 05:58:13 -0500 | asked a question | adding outdoor node list to .osm adding outdoor node list to .osm In openstudio I have a Coil:Cooling:DX:SingleSpeed which I would like to run with inlet |
2019-07-19 03:22:01 -0500 | edited question | Air to air chiller with condenser working with return indoor air AIR TO AIR CHILLER WITH CONDENSER WORKING WITH RETURN INDOOR AIR Good morning everyboby! I have a question about how to |
2019-07-17 09:02:18 -0500 | edited question | OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario I have used the OS:Coil:Cooling:Dx:SingleSpee |
2019-07-17 04:16:26 -0500 | edited question | OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario I have used the OS:Coil:Cooling:Dx:SingleSpee |
2019-07-17 04:13:54 -0500 | asked a question | OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario OS:Coil:Cooling:Dx:SingleSpeed model application outside standard scenario I have used the OS:Coil:Cooling:Dx:SingleSpee |
2019-07-05 05:57:49 -0500 | answered a question | minimum humidity ratio equal to -1000 kgH2O/kgair I took the wrong variables, those are for Set point variables, not the actual variable value in the node. I checked the |
2019-07-05 05:40:25 -0500 | edited question | minimum humidity ratio equal to -1000 kgH2O/kgair minimum humidity ratio equal to -1000 kgH2O/kgair I have a very simple model, an air loop with an "OS:AirLoopHVAC:Outdoo |
2019-07-05 02:43:58 -0500 | edited question | minimum humidity ratio equal to -1000 kgH2O/kgair minimum humidity ratio equal to -1000 kgH2O/kgair I have a very simple model, an air loop with an "OS:AirLoopHVAC:Outdoo |
2019-07-05 02:43:09 -0500 | edited question | minimum humidity ratio equal to -1000 kgH2O/kgair maximum humidity ratio equal to -1000 kgH2O/kgair I have a very simple model, an air loop with an "OS:AirLoopHVAC:Outdoo |
2019-07-04 05:08:19 -0500 | asked a question | minimum humidity ratio equal to -1000 kgH2O/kgair maximum humidity ratio equal to -1000 kgH2O/kgair I have a very simple model, an air loop with an "OS:AirLoopHVAC:Outdoo |
2019-05-04 16:20:03 -0500 | received badge | ● Popular Question (source) |
2019-03-08 06:35:03 -0500 | commented question | Modeling an air to air HP that uses exhaust air as exchanging fluid but there is not "Evaporator Air Inlet Node Name" field in the .osm file to manually edit with a text editor. Can anybod |
2019-03-08 06:33:32 -0500 | commented question | Modeling an air to air HP that uses exhaust air as exchanging fluid I actually managed to model the DX cooling coil (OS:Coil:Cooling:DX:SingleSpeed) to work with the exhaust air, using the |
2019-02-20 09:12:46 -0500 | asked a question | Modeling an air to air HP that uses exhaust air as exchanging fluid Modeling an air to air HP that uses exhaust air as exchanging fluid Hi everyone, I would like to mdel (in openstudio) th |
2019-02-20 05:15:18 -0500 | commented question | Modeling heat pump rejection to the exhaust air stream I have almost the same necessity. I have a rooftop AHU that can provide cooling or heating with an air to air heat pump |
2019-02-20 05:14:39 -0500 | commented question | Modeling heat pump rejection to the exhaust air stream I have almost the same necessity. I have a rooftop AHU that can provide cooling or heating with an air to air heat pump |
2019-01-23 05:16:16 -0500 | marked best answer | Why the building load is not constant even if the weather file/internal loads/thermostats are set constant? I am interested in studying a simple building in which I would like to obtain contstant thermal loads. For this purpose I modified with Elements the weather file, setting 0 for the solar radiation and a constant drybulb/wetbulb temperature. I have also set to 0 the wind speed. This modifications have been made on an existing weather file, and only for the July month (the simulation will be run only in this custom-made month). I deleted all the internal gains, except for the lighs, which are scheduled to be always on and with constant value. I also set up the internal thermostats to be 16°C and constant during the simulation period. The simulation should be for July only, so I have specified this in the simulation settings. I have also selected the simulation to be run only for the weather file run period, I skipped zone sizing calculations, system sizing calculations, plant sizing calculations. I was expecting to have constant building loads during the reported period. Unfortunately, analyzing the variables (with Data Viewer) "District Cooling:Facility" when the ideal loads are on, or the variable "Water to Water Heat Pump Load Side Heat transfer Rate" when I have a plant connected, I can see that there are 31 peaks, exactly the number of days that July is composed. This suggested me that maybe there is still some kind of weather influence. Checking the external temperature and solar irradiation during the simulation periods, they are correctly set to the desired value, both in DViewer and in Elements chart viewer. |
2019-01-15 10:32:59 -0500 | asked a question | Why the building load is not constant even if the weather file/internal loads/thermostats are set constant? Why the building load is not constant even if the weather file/internal loads/thermostats are set constant? I am interes |
2018-11-12 18:06:11 -0500 | marked best answer | Unreasonable heating/cooling loads results Hello again, I apologize for opening so many questions, but I am in desperate need of help since apparently noone in my university knows how to model energy building using openstudio and energy plus. Anyway, as I have written in other questions, I have a AHU system serving a simple model (4 thermal zones), the AHU was modified by me to have, on the heating side, 3 loops linked toghether: the heating coil is connected to a heat exchanger that is linked to a district heating heat source. The cooling side has the chilling coil linked to a absorbtion chiller which is connected to a single speed cooling tower. Now, when I run the simulation I have no unmet hours, which should be great, but the problem arise to the heating loads. Infact, when I analyze the HVAC load profile, I can see that I have a lot of heating request also during hot months (the building is located in Genoa-Italy, which has a july mean temperature of 29 °C) while the cooling load remain very low, both in cold months as well as hot ones. For clarity purposes I will uploads the 4 images regarding the loops and the HVAC load profile graph. My question is: is the software simulation correct? Have I committed any error during the absorption chiller modeling phase? I have tryed to refer both the engineering references here and the input output guide here. One big question is: what are the nodes that I need to specify for the heat generator? I have tryed to edit the .idf file, linking the chiller to the HX-district heating loop, but the simulation fails and I get this error: "ABSORPTION CHILLER" was not found on any plant loops Sorry for the wall of text, and many thanks to everybody who wants to contribute making a young engineer happy! Federico PS: I am attaching also the .osm file if anybody wants to have a look at it |
2018-10-24 06:52:16 -0500 | commented answer | Water to Water Heat Pump Schedule Control Thanks a lot for the help. I have sent an email with the requested file. Please note that the model attached is not the |
2018-10-19 04:48:08 -0500 | commented answer | Water to Water Heat Pump Schedule Control After comparing the results I have found that the Fan Coil Total Cooling Rate reported is now correctly zero when the co |
2018-10-19 04:11:08 -0500 | received badge | ● Enthusiast |
2018-10-18 05:22:55 -0500 | commented answer | Water to Water Heat Pump Schedule Control I have made the maths between these three variables: "System Node Mass Flow Rate: FAN COIL WITH CYCLING FAN FAN OUTLET N |
2018-10-17 05:31:06 -0500 | commented answer | Water to Water Heat Pump Schedule Control The variable you suggested to check are correctly scheduled, so I assume that the system is correctly functioning. Than |
2018-10-17 05:25:42 -0500 | commented answer | Water to Water Heat Pump Schedule Control The variable you suggested to check are correctly scheduled, so I assume that the system is correctly functioning. Than |
2018-10-12 07:38:18 -0500 | commented answer | Water to Water Heat Pump Schedule Control Also, with "Cooling Coil Reports" what exactly do you mean? I have checked water flow rate and for the nodes immediately |
2018-10-12 07:28:19 -0500 | commented answer | Water to Water Heat Pump Schedule Control The fan coil does not have outdoor air, the field in "Outdoor Air Schedule Name" is blank. I have also checked the "Fan |
2018-10-12 05:04:45 -0500 | commented answer | Water to Water Heat Pump Schedule Control Also, with "Cooling Coil Reports" what exactly do you mean? I have checked water flow rate and for the nodes immediately |
2018-10-12 04:45:52 -0500 | edited question | Water to Water Heat Pump Schedule Control Water to Water Heat Pump Schedule Control Hi everybody, I am modeling a NZEB building equipped with a ground source heat |
2018-10-12 04:45:28 -0500 | edited question | Water to Water Heat Pump Schedule Control Water to Water Heat Pump Schedule Control Hi everybody, I am modeling a NZEB building equipped with a ground source heat |
2018-10-12 04:40:44 -0500 | commented answer | Water to Water Heat Pump Schedule Control The fan coil does not have outdoor air, the field in "Outdoor Air Schedule Name" is blank. Also, the "Fan Coil Availabil |
2018-10-10 06:23:15 -0500 | commented answer | Water to Water Heat Pump Schedule Control I have also checked the "Fan Coil Availability Status" variable and, incredibly, is set to zero for all my simulation, w |
2018-10-10 06:17:03 -0500 | commented answer | Water to Water Heat Pump Schedule Control I have also checked the "Fan Coil Availability Status" variable and, incredibly, is set to zero for all my simulation, w |
2018-10-10 05:04:12 -0500 | commented answer | Water to Water Heat Pump Schedule Control I'm sorry for the poor quality image, hovewer it should be clear that when the supply pump that feeds the fancoil heat e |
2018-10-10 05:03:14 -0500 | edited question | Water to Water Heat Pump Schedule Control Water to Water Heat Pump Schedule Control Hi everybody, I am modeling a NZEB building equipped with a ground source heat |
2018-10-10 04:59:58 -0500 | commented answer | Water to Water Heat Pump Schedule Control I'm sorry for the very poor quality of the image, hovewer it should be clear that when the supply pump that feed the fan |