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designbuilder v7 simple hvac seasonal cop has no effect

asked 2022-11-29 01:42:33 -0500

ashopinion's avatar

updated 2022-11-29 09:29:02 -0500

Working in simple HVAC mode, ideal loads, separate fan/pump power.

On the HVAC tab I've used multiple simple HVAC templates, as well as my own and varied the seasonal heating/cooling COP's from 0.8 to 5. These have no effect on the the heating/cooling energy use according to the annual summary energy end use report. Similarly, the HVAC template ventilation tab has a supply fan static pressure that appears to have no impact on energy use, nor does the auxiliary energy use (kwh/sf) on the general tab. Any idea what settings I'm ignoring?

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Hi, I have the same problem, how can i set the COP correctly for see the effect on the energy use? Regards

fernandoasdm@gmail.com's avatar fernandoasdm@gmail.com  ( 2023-05-08 12:03:01 -0500 )edit

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answered 2023-05-09 12:20:49 -0500

ashopinion's avatar

updated 2023-05-11 11:21:14 -0500

Circling back to answer my own question. In "Simple" HVAC mode your system efficiencies are embedded in the HVAC Template you've selected. image description image description

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answered 2023-05-09 16:54:09 -0500

matbla's avatar

The data tab on the right is only part of the help function. It displays the inputs associated with whichever simple HVAC template is being 'viewed'. If you scroll up to the data tab and select the green tick, the data displayed will be assigned via the template to the building, block, or zone (whichever level of the model tree is selected when you make the assignment).

The red bold text inputs indicate that they have been manually assigned to overwrite the assigned HVAC template defaults. Have you tried right clicking on these red bolt text inputs and then selecting 'clear data to default', down to zone level?

If the sCOP input at a deeper model tree level (block and or zone) have been manually assigned as well, then they will be unlinked from the sCOP at the building level. If this is the case, the sCOP input at block or zone will also show as red bold text. This would prevent them being updated when sCOP is changed at building level. By clearing data to default at building level, the relationship between sCOP at zone and block level can be reset so that it can then be managed by the single input at building level. Note that blue text indicates that an input relies on a higher level in the model tree.

Also, It can be helpful to use 'model data grid view' for quickly checking inputs at zone level. Try selecting 'Zone HVAC' in grid view, to view zone sCOP inputs.

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Thank you for the comprehensive response. However, after reviewing in the grid view, it confirms the point that all my zones have the same sCOP for each case (COP 1 and COP 3). However, the "Energy Use" result is still the same, so it doesn't seem to consider the sCOP entered (as I mentioned in another response that hasn't been published yet). Why is this happening? What would be the step-by-step process to configure and see the difference in the simulation? Thank you very much for your help.

fernandoasdm@gmail.com's avatar fernandoasdm@gmail.com  ( 2023-05-09 17:23:31 -0500 )edit

Which report are you referencing? In simple mode I believe the full E+ output report (on the simulation > summary tab) shows the heating and cooling LOADS, not energy USE. The simulation > analysis tab converts that data to energy use based on simple HVAC template specified (which contains the system COP's). I've added a screenshot of the output report below the input screenshot.

ashopinion's avatar ashopinion  ( 2023-05-11 11:21:53 -0500 )edit

Thanks Ash, i was comment previously the solution that i find in other post.

fernandoasdm@gmail.com's avatar fernandoasdm@gmail.com  ( 2023-05-11 15:47:55 -0500 )edit
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answered 2023-05-11 10:43:16 -0500

Thanks everyone, finally the solution indicated in this post by Filipe was useful for me. The effect on consumption of changing COP can be reviewed in Simulation >Analysis > Fuel Breakdown.

https://unmethours.com/question/43535...

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answered 2022-11-30 07:58:39 -0500

Jim Dirkes's avatar

DesignBuilder does not use certain inputs, depending on the way you have configured HVAC calculations in the Model Options tab (the little wrench icon on the tool menu).

If the HVAC tab input is highlighted in green, the input is not used.

I'm not sure, from your description, where you are changing COP - so that's the best I can do at the moment.

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Asked: 2022-11-29 01:42:33 -0500

Seen: 210 times

Last updated: May 11 '23