Hydra JV3 Code Compliance Script

jv3
code-compliance

#1

All,

I am opening this discussion in the hopes that there are some people familiar with the Australian JV3 code on the forum. We have an example file that has been contributed to automate the creation of a baseline JV3 building and it appears to be working well:
http://hydrashare.github.io/hydra/viewer?owner=chriswmackey&fork=hydra_2&id=Energy_Simulation_for_JV3_Code_Compliance&slide=0&scale=1&offset=0,0

However, I am definitely not an expert on Australian code compliance. If anyone who is familiar with the Australian code gets the chance to download it and check the assumptions, please post any thoughts you have here. It seems like having this file validated by a few people will help a number of people save time in this type of compliance.

Cheers!


Implementing Compliance Calculations
#2

Hi @chris , this is great! Thanks so much for everyone involved putting this together!

One thing that I have noticed overviewing the file and maybe could be included (and unfortunately I don’t know how to do it) is that depending on the climate zone we need to reduce the R-value of the south facing walls by 0.5 in the reference model.


#3

@mtonellis ,
Thank you for the feedback and for taking a look at the script. I will add something in now that allows you to reduce the R-value by 0.5. I don’t know if I am understanding the table correctly. Am I right in understanding that only these cities need to have - 0.5 R-value:

Canberra
Sydney
Darwin
Brisbane
Adelaide
Hobart

… and these cities do not have this:

Perth
Port Headland
Melbourne
Richmond RAAF
Wagga Wagga


#4

@mtonellis ,
I pushed a change to the example file assuming that the climates above follow the condition of having Wall R-values with - 0.5:

Let me know if you get the chance to check it out and confirm that it is working as you expect.


#5

Hi @chris, you are kind of right. But there are more weather files and areas than the 10 defined cities.
Maybe it would be better to break down in Climate Zones 1-8 (instead of cities) to define the properties of the reference model and Weather File to select manually the one closer to the project site you are analyzing.

Another thing is that walls shaded by a projection angle more than 30 degrees (orange marker in the image below) reduces the r-value of the wall for the reference model aswell …
In my opinion there a lot of conditions to be analyzed to define the r-value of walls. Maybe if we add another part in the end to overwrite some r-values of particular orientations or external walls for finer analysis.

I believe having a preview of both files side by side (reference and proposed) with information about the r-values and glazing would be a good way to QA this issues we have been discussing before running the simulations.

Thanks again ! Its an amazing work.


#6

@mtonellis ,

Ok. So is the climate zone just the ASHRAE climate zone or does Australia have its own climate zoning system?

For some reason, I thought those cities were selected because they were representative of some Australia climate zones. Maybe I just didn’t realize that ASHRAE is used in a lot of other places outside of the US.

If it’s just the ASHRAE climate zones, we can import the .stat file that sits next to the .epw to automatically set the south wall R-value based on the climate zone.

For the 30 degree angle projection, maybe we just pick the more conservative R-value for the baseline since this seems like we are letting the edge cases drive the core functionality of the tool. We can do a QA visualization in the Rhino scene, though, as that is easy to set up.


#7

Ok. I just set it to read the ASHRAE climate zone since these seem to be the same as the US’s ASHRAE climate zones:
http://www.trendwindows.com.au/wp-content/uploads/2014/06/BCA2009_Climate_Zone_Map_-_Australia11.pdf

I also fixed a few minor errors that @Edmund made me aware of including:

  1. Changed OA per person to 0.0075 m^3/s

  2. Defined Solar absorptance for reference roof to 0.7 (default 0.7)

  3. Defined Solar absorptance for reference wall to 0.6 (default 0.7)


#8

Actually, now that I check it, it seems that the ASHRAE climate zone of Melbourne is 3 but the Australian Climate zone is 6. If anyone knows if it’s possible to get the Australian climate from the EPW or STAT data, please post here. Otherwise, we can add a manual input for Australian climate zone.


#9

Hi @chris , sorry for the late response. Yes, Australian Climate Zones:

https://www.abcb.gov.au/Resources/Tools-Calculators/Climate-Zone-Map-Australia-Wide

I’m not sure if you can get this information from the weather file.

Kind regards,


#10

The problem is, climate zones don’t correlate between Australian BCA and ASHRAE.
I did a quick comparison, but even by looking at two maps, they split the country in different ways.

Ashrae BCA
Canberra (CTA) 4a 7
Sydney (NSW) 3 5
Penrith/Richmond (NSW) 3c 6
Bathurst (NSW) 3c 7
Griffith/Dubbo (NSW) 3c 4
Melbourne (VIC) 3c 6
Brisbane/GC (QLD) 2 2
Cairns (QLD) 2a 1
Adelaide (SA) 4 5
Albany (WA) 3c 6
Perth (WA) 3 5
Alice Spring (NT) 2 3
Darwin (NT) 1 1
Hobart (TAS) 4a 7

image


#11

Hi All,

I was playing with this today and note there is an issue in the glazing calculator cluster.
There is anomalies in the code the calculate an SHGC >1 for a small number of scenarios.
image

I have added an equation to the cluster.

Let me know if this is unclear.


#12


#13

All,

Thank you for all of your comments and feedback. I have just pushed an updated version of the script to the hydra download link. The new Grasshopper def now has the following fixes:

  • I no longer use the ASHRAE Climate zone and I added a list of climate zones that correspond with the city selection in the slider in the upper left.

  • I added @Sam 's fix to the cluster.

If anyone else finds anything that needs to be changes, just post here and I will make sure that it gets into the file.