# Ground sourced central heatpump

**URL:** <https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608>\
**Category:** ironbug\
**Tags:** energy\
**Created:** [November 8, 2019, 10:24am UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608 "2019-11-08T10:24:06Z")\
**Posts on this page:** 12\
**Page:** 1

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**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 8, 2019, 10:24am UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/1 "2019-11-08T10:24:06Z")

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Hi @MingboPeng,

I am trying to build a central heatpump system without a chilled water loop, using the Ironbug HVACTemplate (Other/GSHP\_CentralHeatPumpPlantloops). When I detach the chilled water loop, and run the simulation with the export to Openstudio node, Rhino crashes. When I open the Openstudio file all plantloops (HVAC systems) seem to be modeled in the right way (except for the parameter settings). Two air loops one hot water loop and one heat pump loop.

[2A.osm](https://discourse.ladybug.tools/uploads/short-url/fOPdbmWqkGnSFfoPZHqfq50NWUk.osm) (1.1 MB)

Is there an other way to model this system.

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/d/de03b88fc300c7f26a0be030c7d6bc6716db5013.png)

… I just found out that when I run my model the OpenStudio file opens with all geometry and instalations in it, but energyplus does not start and probably causing Rhino to crash.

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**Author:** ![MingboPeng](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/mingbopeng/32/5084_2.png) [@MingboPeng](https://discourse.ladybug.tools/u/MingboPeng)\
**Post date:** [November 8, 2019, 4:59pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/2 "2019-11-08T16:59:48Z")

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@Erikbeeren did you try to use regular heat pump if you only need heating?  
(Central heat pump should also be working, but not sure what cause the crashing, will dig into later.)

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/b/b4304e075670f5b812185bff1a9d40c033280d76.png)

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 11, 2019, 8:42am UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/3 "2019-11-11T08:42:07Z")

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Hi @MingboPeng  
This works fine. Thanks again!

For your information. This was the error report wich was sent to Rhino:

November 07 at 02:39 PM in Rhino version 6.20.19302.15121:  
openstudio\_translators\_csharp!openstudio\_translators\_csharp – Access Denied  
A Rhino 3DM file was included with your report.

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 11, 2019, 4:05pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/4 "2019-11-11T16:05:31Z")

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Hi @MingboPeng,

There is i think a small bug in AirloopHVAC system sizing.  
When attaching the object parameters component it asks for “MinimumFlowRatio”  
When I look at the output file this number is defined as “Central Heating Maximum System Air Flow Ratio”

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/7/750e6f3103004297e81617e8d7e8431bae976e47.png)

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<div class="post-metadata">

**Author:** ![MingboPeng](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/mingbopeng/32/5084_2.png) [@MingboPeng](https://discourse.ladybug.tools/u/MingboPeng)\
**Post date:** [November 11, 2019, 5:01pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/5 "2019-11-11T17:01:58Z")

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Hi @Erikbeeren , “Central Heating Maximum System Air Flow Ratio” is a revised name of “MinimumFlowRatio” in newer version of energyplus.

> **[Group – Design Objects: Input Output Reference — EnergyPlus 9.2](https://bigladdersoftware.com/epx/docs/9-2/input-output-reference/group-design-objects.html#field-central-heating-maximum-system-air-flow-ratio)**
>
> Input Output Reference — EnergyPlus 9.2

> The ratio of the maximum system air flow rate for heating to the maximum system air flow rate. The value must be between 0 and 1. For constant volume systems the ratio should be set to 1. This ratio should be set to reflect what the user expects the system flow rate to be when maximum heating demand occurs. **This ratio is used in calculating the central system heating capacity. Thus if the system is VAV with the zone VAV dampers held at minimum flow when there is a zone heating demand, this ratio should be set to the minimum flow ratio.** If the zone VAV dampers are reverse action and can open to full flow to meet heating demand, this ratio should be set to 1. The default is set to 0.5, reflecting the fact that VAV dampers are typically not allowed to fully open during heating.
> 
> This field can be set to _AutoSize_ . When automatically calculated, the ratio is determined from the system heating design flow rate divided by the main (which is usually the max of heating and cooling design flow rates) design flow rate. The design flow rates are also adjusted to be more accurate by examining each of the air terminals attached to the air system and summing the heating and maximum flow rates.

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 12, 2019, 12:09pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/6 "2019-11-12T12:09:35Z")

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Hi @MinboPeng,  
I am using Energyplus V9-0-1. I installed Energyplus 9-2 but from Honeybee I get the following message:

Honeybee cannot find an EnergyPlus folder on your system.  
You wont be able to use the Run Energy Simulation component.  
Honeybee supports following versions of EnergyPlus:  
V9-0-1, V9-0-0, V8-9-0, V8-8-0, V8-7-0, V8-6-0, V8-5-0, V8-4-0, V8-3-0, V8-2-10, V8-2-9, V8-2-8, V8-2-7, V8-2-6, V8-2-5, V8-2-4, V8-2-3, V8-2-2, V8-2-1, V8-2-0, V8-1-5, V8-1-4, V8-1-3, V8-1-2, V8-1-1, V8-1-0

It looks like version V9-2 is not supported yet.

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<div class="post-metadata">

**Author:** ![MingboPeng](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/mingbopeng/32/5084_2.png) [@MingboPeng](https://discourse.ladybug.tools/u/MingboPeng)\
**Post date:** [November 12, 2019, 3:19pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/7 "2019-11-12T15:19:09Z")

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If you have the newest OpenStudio installed, the new EnergyPlus comes with OpenStudio already. You don’t have to install EnergyPlus separately.

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 12, 2019, 3:27pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/8 "2019-11-12T15:27:00Z")

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Openstudio 2.9 is the latest version. I have now running 2.8.  
Does Honeybee supports this version?

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<div class="post-metadata">

**Author:** ![MingboPeng](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/mingbopeng/32/5084_2.png) [@MingboPeng](https://discourse.ladybug.tools/u/MingboPeng)\
**Post date:** [November 12, 2019, 3:33pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/9 "2019-11-12T15:33:12Z")

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yes, you should be fine.

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 12, 2019, 4:28pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/10 "2019-11-12T16:28:58Z")

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I am having some problems with openstudio 2.9  
I checked the energyplus file in the openstudio folder and it seems to be version 9-2

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/b/ba3deab7dbac370391c7f7a25b3ec572cf149bf2.png)

Honeybee although thinks it is still V9-0-0

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/6/60efb3232a470d715f2e678b896c31bc71531aa9.png)

But more important the simulation is not running properly.

 ![image](https://discourse.ladybug.tools/uploads/default/original/2X/a/a160c116d3f50beda921aaa6769d87ca9cd2481c.png)

Openstudio gives the following message:

![image](https://discourse.ladybug.tools/uploads/default/original/2X/1/141ef822c7aef9543c158a2e9f1a472899125ab2.png)

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<div class="post-metadata">

**Author:** ![MingboPeng](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/mingbopeng/32/5084_2.png) [@MingboPeng](https://discourse.ladybug.tools/u/MingboPeng)\
**Post date:** [November 12, 2019, 5:17pm UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/11 "2019-11-12T17:17:07Z")

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This is a different issue, let’s start a new post.

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<div class="post-metadata">

**Author:** ![Erikbeeren](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/erikbeeren/32/8868_2.png) [@Erikbeeren](https://discourse.ladybug.tools/u/Erikbeeren)\
**Post date:** [November 13, 2019, 7:39am UTC](https://discourse.ladybug.tools/t/ground-sourced-central-heatpump/7608/12 "2019-11-13T07:39:30Z")

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You are right! I will call it Openstudio 2.9.