Question

Asked 30 July 2016

University of Tripoli

Does anyone know how to model a split unit air conditioner in OpenStudio?

I am trying to model an air conditioning split unit in openstudio . I found PTHP and PTAC but I can not find the suitable component for a split unit.

Is there a built-in component? If not what is the alternative?

Air Conditioning

Energy Modeling

Phoeurng Tork

Institute of Technology of Cambodia

How to model a split unit air conditioner in Open Studio?

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1 Recommendation

Nazaruddin Sinaga

Diponegoro University

Srinivas Kasulla

Arka Brenstech Private Limited

Arvind Singh

Banaras Hindu University

Abiodun Olusola Omotayo

North-West University

Sule Akkoyunlu

Rimini Centre for Economic Analysis

I suggest subscribing to www.unmethours.com and asking the same question there. There are a lot of OpenStudio/E+ users there.

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1 Recommendation

Samah K Alghoul

University of Tripoli

Thanks Fred, that is exactly what I did and it looks that there is no builtin component for split units. The alternative is to build a custom air loop by using the following objects:

AirLoopHVAC:UnitaryHeatPump:AirToAir:MultiSpeed

Coil:Cooling:DX:Multispeed

Coil:Heating:DX:Multispeed

Fan:OnOff

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

No split unit available in Open studio and EnergyPlus, and it's very hard to make your own model

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Samah K Alghoul

University of Tripoli

Thanks Ahmed, So how do think I could do it?

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Hi Samah, I found the following for you :

"EnergyPlus HVACTemplate:System:Unitary and HVACTemplate:System:UnitarySystem both can be used to model a split system or a rooftop system. HVACTemplate:Zone:PTAC is intended for a non-split through-the-wall type of system, but it can also be used. All three of these systems model essentially the same set of components and can apply to split systems or rooftop systems given appropriate efficiency and fan pressure inputs"

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

and another solution I found was

" use one of the zone HVAC systems (like PTAC) or use an AirLoopHVAC based system with a AirLoopHVACUnitary component inside of it to manage the cycling. OpenStudio does not support reconfiguring zone equipment graphically in the application, therefore you cannot graphically replace the water coil with an electric heating coil. Certainly this is possible with a measure but I'm going to assume that you would rather use the UI. So go the AirLoopHVAC route following these steps to build up a system from components."

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Create a new empty AirLoopHVAC system.

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Add an oa system

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Add an AirLoopHVACUnitarySystem. You want the one with DX cooling, cycling, and electric "reheat", which will really just be heat in this case.

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Attach your zone.

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Add an uncontrolled terminal.

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Edit the unitary system and make sure that the attached zone is specified as the Controlling Zone.

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

Check the following:

http://www.worldscientific.com/doi/abs/10.1142/S2010132514500060?journalCode=ijacr

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Ahmed Y Taha Al-Zubaydi

University of Technology Sydney

or try another package like DesignBuilder Software (not free)

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Sifuentes Ayala Marco Antonio

Instituto Tecnologico de Veracruz

How to model a split unit air conditioner in Open Studio?

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1 Recommendation

Phoeurng Tork

Institute of Technology of Cambodia

How to model a split unit air conditioner in Open Studio?

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1 Recommendation

How does Energyplus-based software calculate heating load and heat loss through building envelope?

Question

6 answers

Asked 27 November 2017

Xinrui Lu

Hi there,

I'm trying to explore how does Energyplpus-based software tools, like BEopt, Designbuilder,etc calculate the heating load. For example, if the outdoor temperature is 20°C， does Energyplus use the outdoor temperature and the properties of building envelopes to predict the indoor temperature, and then use this temperature difference to calculate the heating load? Or it just set the indoor setpoint like 25°C, and for whatever the outdoor temperature is, it uses the temperature difference between outdoor temperature and the indoor setpoint to calculate the heating load and heat loss? Any helpful suggestions is greatly appreciated.

Is it possible to simulate a hydronic cooling masonry wall in EnergyPlus?

Discussion

3 replies

Asked 12 July 2021

Mohammad Rezvanpour

Hi friends,

I hope you all are doing well.

I'd like to simulate a hydronic radiant cooling system. Through pipes, water goes inside a masonry/concrete wall and cools down the room temperature. We will use the warmed water for another purpose. What I am interested in is how the wall would perform in terms of energy performance/thermal response, how the air temperature would fluctuate when in contact with the wall, how long pipe I need, etc.

Do you think EnergyPlus can be used in order to simulate this type of system or similar ones? My experience with EnergyPlus is limited, so I would appreciate any help you can provide.

Best,

Mohammad

Specifing ground monthly temperatures (Site:GroundTemperature:BuildingSurface.) in an energy-plus residential building model ?

Discussion

5 replies

Asked 27 February 2020

Adel Boumerzoug

The Energy plus documentation (input/output) specifies that for typical commercial buildings in the USA, a reasonable default value for ground temperature: building surface is 2 degC less than the average indoor space temperature. And a practician in 2011 mentions that he has seen many simulations doing simplified method:

- using the last month's mean temperature, less 1 degree.

( http://energy-models.com/forum/ground-temperature-building-surface )

Similar to the Energy+ O/I documentation and Aside from applying:

Auxiliary programs that can be simulated independent of the IDF file and determine detailed ground heat exchange ------ Ground heat transfer modeling " with "kiva"
Ground Temperature Calculation through a Basement\slab Calibration process.

- What is the best and easiest (more abstract) method, to input reasonable default values as a ground monthly temperature for small/large residential building models?

Could you help related to the following Optimization issue in DesignBuilder?

Question

5 answers

Asked 25 April 2024

Mohamed Mamdouh Yusuf Hussein

I made a DesignBuilder model that includes PV solar collectors using two electric load centers. After simulation, the annual PV generation was about + 3700 KWh.

Then, I identified an optimization problem with two objectives (minimize thermal discomfort and maximize PV electricity generation). The decision variables are windows ratios, wall materials, and building rotation, while any parameters related to PV solar collectors design are kept constant.

In the optimization results, the power generation values are negative. Consequently, the optimum design scenarios and the pareto front are misleading.

Has anyone else received this email? Is this the scam?

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78 answers

Asked 17 December 2023

Fariha Kanwal

risa@akisic.info

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How to control parameters in Energyplus during Runtime Actuation?

Question

5 answers

Asked 26 July 2023

Sarath Mani

Hi everyone. I’m trying to implement some papers that control a few parameters during runtime. I’m using Gym-Eplus to vary the values but I’m not sure if the following can actually be controlled.

How can we control the frequency of a VFD during runtime using an actuator? (In Hertz)
Is the Return Air Outlet’s Setpoint Temperature similar to what is observed as Return Air Temperature Setpoint in BMS systems?
How can we vary the Fresh Air Damper’s opening percentage in a chiller system during runtime using an actuator?
How can we vary the chilled water valve opening percentage to an AHU system during runtime using an actuator?

I couldn’t find any relevant actuators in the .edd file created.

There is two errors during the solving part in ANSYS workbench. Is there any solutions?

Question

1 answer