Unmet Hours - RSS feedhttps://unmethours.com/questions/Question-and-Answer Resource for the Building Energy Modeling CommunityenMon, 14 Dec 2015 08:43:03 -0600Standard Ratings for Chiller:Electric:EIRhttps://unmethours.com/question/13197/standard-ratings-for-chillerelectriceir/ I need the standard rating values for COP and Cooling Capacity for chillers for some post processing of model simulations. DX Cooling Coils have these output parameters defined, but are not always output in the HTML file produced from the E+ simulation. However, I was able to find formulas to calculate these values for Single and Two Speed DX Cooling Coils. For DX Cooling Coils, the formulas for these were explicitly stated in the **Engineering Reference PDF v8.4** in the energy plus documentation. However, for chillers, no such formulas are provided, and it is not produced in the HTML file generated from an E+ simulation. Only Nominal values for Cooling Capacity and COP for chillers are output. If anyone could point me towards formulas or share why there would not be such an output, I would be greatly appreciative. For example, I was using Equations 217 and 220 in section **16.2.6.6 Standard Ratings** of the Engineering Reference PDF v8.4 to calculate the Standard Rating Net Cooling Capacity and Standard Rating EER, respectively. Mon, 07 Dec 2015 10:17:52 -0600https://unmethours.com/question/13197/standard-ratings-for-chillerelectriceir/Answer by Archmage for <p>I need the standard rating values for COP and Cooling Capacity for chillers for some post processing of model simulations. DX Cooling Coils have these output parameters defined, but are not always output in the HTML file produced from the E+ simulation. However, I was able to find formulas to calculate these values for Single and Two Speed DX Cooling Coils. For DX Cooling Coils, the formulas for these were explicitly stated in the <strong>Engineering Reference PDF v8.4</strong> in the energy plus documentation. However, for chillers, no such formulas are provided, and it is not produced in the HTML file generated from an E+ simulation. Only Nominal values for Cooling Capacity and COP for chillers are output. If anyone could point me towards formulas or share why there would not be such an output, I would be greatly appreciative. For example, I was using Equations 217 and 220 in section <strong>16.2.6.6 Standard Ratings</strong> of the Engineering Reference PDF v8.4 to calculate the Standard Rating Net Cooling Capacity and Standard Rating EER, respectively. </p>
https://unmethours.com/question/13197/standard-ratings-for-chillerelectriceir/?answer=13331#post-id-13331Standard Ratings reporting has been added to the program for various HVAC components over time. It is a really great check that the inputs are working with the model as expected. However this has not yet been added for Chiller:Electric:EIR. You might add this to the User-voice site for new feature requests to help prioritize this work.
Although recreating the model from the engineering equations seems okay to me, there is another way to go that may be easier, and more valid, which is to use the program with a separate, simple IDF that serves as a sort of test harness. The idea is to emulate the chiller testing protocol in the software. Execute the chiller model with the same chiller input data you have in the building model inside a special IDF that is setup to apply the conditions specified for standard ratings. With clever use of district heating, load profiles, setpoint managers, and operating schemes (maybe EMS if you hit a wall), it should be possible to create a simple IDF file that loads the chiller as called for in the governing standard. This is essentially what is done inside the program when Standard Ratings reports are added, but it is possible to do with input files and no programming changes. For IPLV you would have a set of similar IDFs that load the chiller as prescribed and then postprocess the results.
Mon, 14 Dec 2015 08:43:03 -0600https://unmethours.com/question/13197/standard-ratings-for-chillerelectriceir/?answer=13331#post-id-13331