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Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

********* UPDATE ******

I have looked at the sizing runs instead of the annual period runs and extracted chiller variables to confirm peak chiller size that is being sized based on design days. The image below, also in this spreadsheet, shows how I am extracting the peak cooling loads that the chiller sees and should be used for chiller sizing based on the design cooing day.

C:\fakepath\Chiller sizing question_sizing runs.jpg

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

********* UPDATE ******

I have looked at the sizing runs instead of the annual period runs and extracted chiller variables to confirm peak chiller size that is being sized based on design days. The image below, also in this spreadsheet, shows how I am extracting the peak cooling loads that the chiller sees and should be used for chiller sizing based on the design cooing day.

C:\fakepath\Chiller sizing question_sizing runs.jpgit.

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

********* UPDATE ******

I have looked at the sizing runs instead of the annual period runs and extracted chiller variables to confirm peak chiller size that is being sized based on design days. The image below, also in this spreadsheet, shows how I am extracting the peak cooling loads that the chiller sees (or should see) and should be used for chiller sizing based on the design cooing day.

C:\fakepath\Chiller sizing question_sizing runs.jpgIt can be seen that the peak chiller cooling loads are still a fraction of what is reported in the "Equipment Summary" tab, see in the image above. I have saved all the different idf versions used for this exercise in this folder. It appears to me that there is either an error in the way values are reported or converted in the HTML reporting versus what is being seen in the hourly results. I have reported this as an issue on the [Energyplus github page]. (https://github.com/NREL/EnergyPlus/issues/9211). Am I missing something here?

Working on an office renovation project in Northeast. The mechanical engineer is interested in knowing the chiller size resulting from recent arch modifications...Long story short, this has happened before too that I notice the chiller sizes reported in the equipment summary are way higher than expected compared to typical sizing benchmarks (around 250-350 sqft/ton) and have also observed discrepancies compared to the hourly "Cooling:Electricity" results.

For sanity check comparing to the equipment sizing report I have extracted the hourly "Cooling:Electricity" meter from the eso file and looked at the peak value (in Joules), converted it back to kBtu electricity used to run the chiller and have back-calculated the peak chiller tonnage with the reference nominal chiller COP of 6 which is in the idf. The full set of data and some screenshots of relevant idf sections are also attached in [this excel sheet] for more (https://cannondesign.box.com/s/dz32wjv9klhsvr2dc1c77zgrkj2bnzpj). Also a link to the idf file.

What I don't understand is:

1. Why is the reported chiller size on the equipment summary table so much higher than peak observed in the hourly results?

2. I do have a 1.15 cooling sizing factor which should explain the difference between the AHU cooling coil total caps and total chiller cap. I also notice a large difference between the cooling coil "Design Coil Load [Btu/h]" and "Nominal Total Capacity [Btu/h]" which I can't explain

3. Is it possible that the chiller curves are what messing my calculations up from the hourly results to sizing?

Last but not least, perhaps a suggestion for the E+ development team is to build in more typical sizing benchmark checks and balances in these E+ reports similar to what Trace 700 has pioneered (sqft/ton etc.) that many designers are used to seeing and checking. Many software developers have taken it upon themselves to mimic these types of reports but perhaps the E+ development team can connect the dots in generic sizing reports as well to avoid these types of consulting led checks and balances?

I have done a cursory read through the recent and past bug history on the github here, here and here as it relates to cooling and chillers and I am not sure if there is more too it.

********* UPDATE ******

I have looked at the sizing runs instead of the annual period runs and extracted chiller variables to confirm peak chiller size that is being sized based on design days. The image below, also in this spreadsheet, shows how I am extracting the peak cooling loads that the chiller sees (or should see) and should be used for chiller sizing based on the design cooing day. It can be seen that the peak chiller cooling loads are still a fraction of what is reported in the "Equipment Summary" tab, see in the image above. I have saved all the different idf versions used for this exercise in this folder. It appears to me that there is either an error in the way values are reported or converted in the HTML reporting versus what is being seen in the hourly results. I have reported this as an issue on the [Energyplus github page]. (https://github.com/NREL/EnergyPlus/issues/9211).

Am I missing something here? I have even used a sizing safety factor of 30% on top of the hourly peak values from the sizing runs but the reported chiller size on equipment summary is at 1,387 tons compared to 530-560 tons after a 30% safety factor increase which is approximately 2.5 times higher. Not to mention, this is an office building and compared to typical cooling sizing benchmarks at 209,000 sqft the higher value reported on equipment summary results in 209,000/1387= 151 sqft/ton which is way outside expected norms for an office building in the 300-350 sqft/ton and is closer to what a high load lab building will be.