Problems with modelling Radiant cooling and VRV in Design Builder

Dear All,

Greetings. I am Kartikay Sharma (kartikay.sharma.mtech15@cept.ac.in), student for MTech Building Energy Performance at CEPT University. I am Right now using Simulations as a tool in my thesis to estimate the energy savings potential of buildings. For this purpose, I am using DesignBuilder to simulate all ECM/EEMs. Three of my selected ECMs are : 1. ECBC compliant chiller(centrifugal with 6.3 COP with VAV AHU and VAV terminal units) 2. VRV systems 3. Radiant cooling

My base-case system uses a water cooled system with an screw chiller of 5.2 COP and Constant Air Volume (CAV) AHU. The problem that I am facing is that, I am getting higher savings(overall EPI savings) if do ECM1 listed in table, but looking at case studies the savings from ECM3 should be higher than ECM1. Similarly I am facing problems with ECM2. The weather selected for my building is Hot and Dry climate of Ahmedabad.

So I request all the members to help me in the same

kksharma3951

asked 2017-04-20 09:44:41 -0500

4.4k

__AmirRoth__

updated 2020-01-25 18:19:19 -0500

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Hi Kartikay,

Javed Iqbal seems to have answered your question on the Bldg-Sim list today. Having looked at your models he has identified a number of potential issues with your data inputs. You can't assess ECMs until you are confident your model is set up and working correctly, particularly when you are modelling detailed EnergyPlus HVAC systems.

I presume you are fully familiar with the correct setup of such HVAC systems in real life, but you must also check that these systems have been appropriately sized and are operating correctly in the model. The only way to do that effectively is to review the "Summary" tab in the simulation results screen (here you can find all the sizing data etc.) and also, importantly, you must use the Results Viewer to analyse system performance in more detail. This will tell you HVAC system component flow rates and temperatures for example.