Naming Doas branches and results

Hi @chris,

I think I posted something earlier on this issue, but I could not find the post anymore. It is about a big building with zones arranged in different Doas Branches. Each branch was given a name. When I look in the output sql file (Doas HGT Coil output) all names are gone. Once I know some of the names where there.

I ran the simulation two times with different simulation parameters (terrain: Ocean and Suburbs). When I compare the results of both simulations there are some unrealistic differences in energy use for some DOAS heating Coils. Some of the doas HGT coils need 10 times more energy. Also the naming of the coils in these two simulations is a little bit different. Especially one of the 10 ZONE DOAS HGT Coils differs unrealistically.

I have a feeling that something is not goiing like it should go.

I used the LBT1.2 version.

210923_Basis_KRAP_11_LBT.7z (471.1 KB)

Hi @Erikbeeren ,

The names of your Air Loops are going into the OpenStudio Model on my end:


I’m using LBT 1.3, though.

I don’t know why the system would have 10 times the energy use simply because you changed the terrain. I would expect the higher wind speed with the Ocean to boost the heat a little but it’s odd that it would change by that much. Are you sure that the EnergyPlus results is truly 10 times larger and there isn’t something happening between the raw E+ result and the postprocessing to get to that excel sheet?

Hi @chris,

In Openstudio I can see some of the names, but not all.

The amount of DOAS branches is correct, however not all names are passed through.
For some of the branches the names are mixed up and put together.

In the HB model everything looks correct. (amount of rooms and amount of DOAS branches)

For checking the results I have the folowing difficulty: The name of the system is not visible in the name of the heating coil so it is difficult to see which coil belongs to which DOAS branch. Especially when reading the sql file. I do not know if it is possible to add here some more information. Also some of the naming is different. (4 ZONE DOAS HTG COIL 1) versus (4 ZONE DOAS 1 HTG COIL)

With the post-processing I did not do strange things. It is basically just a mass addition.

When I look at the results it does not look good.

The results of the FCU coils however seem to be correct (nothing strange there). So I think there is something not goiing correct with the DOAS system. Maybe because of setting different humidity setpoints or progam types to one DOAS branch. Or because of the incorrect naming.

Hi @Erikbeeren ,

Did you upgrade to LBT 1.3? This was a bug in LBT 1.2 that you had reported a few months ago and it has since been fixed. When I upgraded your .gh file to LBT 1.3, all of the DOAS loop names in the resulting OSM are correct:

Hi @chris,

I updated to 1.3. But somehow adding the HVAC system does not work anymore.
Error message: 1. Solution exception:name ‘dcv_’ is not defined

I had to replace manualy the component.

The results look now much more trustworthy. Thanks @chris

Hi @Erikbeeren ,

Glad that it all worked out.

You should use the LB Sync Grasshopper File component to automatically sync your Grasshopper definition with your current installation. For the few components that need to be replaced manually (like the DOAS HVAC component), the “Sync Grasshopper File” process will circle these in red and place an updated version of the component right next to it.