Running Isolated Zone Simulation for Overheating Assessment

tm59

#1

Hi Everyone,

I’ve recently been trying to run a simulation to estimate the level and severity of overheating in a mid-rise apartment. I’m having trouble determining how to isolate a specific apartment within a wider block and have the adjacencies recognise as ‘InteriorWall’ and ‘Adiabatic’ to the surrounding zones.

Attached is my poor first attempt, but I would be grateful if someone could suggest a Honeybee workflow to model this type of simulation effectively?

Many thanks in advance.
James

GH Energy Analysis TM59 OVERHEATING.gh (866.8 KB)


#2

Hi @jwoodall - I tried to open your file, but it seems that your geometry is not internalised. However, I noticed that you are using the _Masses2zones component.

If of any help, I normally create zones (_createHBzones) from individual surfaces (_createHBsrfs). It takes more time, but I find that I have more control over the model. Image below from a HB workflow I was working on couple of weeks ago. If @mostapha or @chris could propose a faster workaround, I would be glad to know it too.

Also note that you would need to create custom occupancy, equipment & lighting schedules and internal gains in line with CIBSE TM59 (picked this up from your file name).


#3

In some cases it is faster to create the zones with Masses2Zones component, pick the specific zone that you are trying to customize and use Decompose Honeybee Zone component to get the surfaces, modify them and put them back together as a zone.


#4

@OlgaT Thanks so much for the tips. This is useful as a basis to begin adding surface specific attributes.
Thanks also for the note on TM59 - I hadn’t completed the model at that point but the intention is to begin to add custom schedules in line with TM59 once done.


#5

Is this something that we should start to include as a part of the standard library? We had a number of discussions about starting a category for building code and develop/collect sample files for best practices for rating systems/building code around the globe. @chris and I even drafted the post but never posted it to discourse. This is something that we can’t do ourselves but with the help from the community is possible and will be beneficial for everyone.


#6

@mostapha - I can definitely help point out the resources we usually refer to as industry guidance documents and ‘standardised’ modelling inputs in the UK. I’m not a ‘coder’, therefore I’m not sure if I could be able to help on a more bespoke development side of things…

However, yes - I think it would be very useful in general. I would presume we are many people in the forum, practising in other parts of the world, and probably quite a few of us in the UK. Personally, I’m modelling in LB/HB for design optimisation purposes, but when I need to undertake a planning compliance overheating assessment I will re-build the ‘optimum’ solution in Design Builder, since it provides automated modelling inputs and results templates in line with CIBSE requirements. It would be helpful if we had something similar in HB.

In terms of overheating assessments, we use the CIBSE TM52 (for non-domestic buildings) and CIBSE TM59 (for domestic buildings), which require dynamic thermal modelling - both attached in PDF.

CIBSE TM52 doesn’t specify particular schedules, but there is kind of an ‘unwritten’ industry agreement to use the NCM (National Calculation Methodology), which are the ones used for SBEM calculations - SBEM is not dynamic energy modelling, but it provides compliance against the Building Regulations here. I’m not an SBEM modeller myself, but I know from people I used to work with, that it’s a pretty simplistic (and boring…) approach. NCM is a quite big database, and therefore I wouldn’t say it would be practical to develop sample files for each and every use class. However, I have downloaded a Microsoft Access file - zip file attached - I don’t know if there’s an easy way to ‘stream’ these data into GH or HB databases.

CIBSE TM59 provides standardised gains and schedules for domestic rooms (bedrooms, living rooms & ktichens). These can be found summarised in page 8 of the PDF. Also, Table 1 in page 5 mentions default heat-losses from pipework, since normally at concept stage MEP people don’t have detailed distribution schematics to provide us with more accurate values. To be honest, I haven’t yet tried to model in such a detail in HB to include communal corridors and heat-losses from pipework - it’s in my to-try-list.

I’m currently in a process of creating a sample schedule/gains file for TM59 - although there’s a question of how to insert fixed sensible and latent occupancy loads in HB. I’m also trying to post-process the results from the Adaptive Comfort Chart to match the TM59 result requirements. I could create a separate post for this once I have something more solid in my hands. Probably, I would need some help/review, but I’ll be happy to share it afterwards. I guess the methodology could be considered as applicable outside the UK too.

CIBSE TM52 2013 The Limits of Thermal Comfort- Avoiding Overheating in European Buildings NEW 2013 (1).pdf (1.3 MB)

CIBSE TM59 2017 Overheating.pdf (1.8 MB)

NCM_databases_v5.4.b.zip (1.9 MB)


#7

Hi @OlgaT,

Thank you for the explanation and details. I think we should start a separate topic to discuss this. All you said makes sense and I think we can help with automating parts of the “boring” workflows and you and other practitioners can help with validating the results and provide the sample files. In this case, the main help will be providing resources and sample files as you did and not coding. Thanks again. Cheers.


#8

@mostapha - Sounds good! Once I have a bit of free time over the next couple of weeks, I’ll get back on this.


#9

@mostapha, @OlgaT this would be a great addition to the lb/hb toolkit, and help with streamlining assessments for national code based methodologies that require standardised approaches. Although this shouldn’t be at the expense of use as a tool for optimising design at the early stages of development, it will help as a ‘yardstick’ for these compliance methods. Happy to lend a hand if required.


#10

Can I get this file? I’d like to learn more about columns 4 and 6 in this image. Internal gains, vent/air and natural vent. Thanks


#11

Are there any updates on this?

I would be happy to help! I am not a coder as well, but I am currently looking into the same topic and will be developing a workflow for CIBSE TM 59 overheating assessment soon. Creating a toolkit for rating systems and standards would be great and would make the process much faster and easier. I am sure this would further encourage the use of parametric design in industry.