BR 209 post processing for CDBM approach

[charliebrookerBH]

Description:

Method to post process results from an annual daylight simulation to give result against BR 209 criteria.

Input should be the results folder from an LBT annual daylight simulation.

Variables to consider is the room type

Here's an example of how I'm handling a single room atm

ldk_results = []
for ill in ldk_ills:
    print(ill)
    df = load_ill_file(ill_file=ill)
    df = df.T
    median_per_timestep = df.median()
    median_result = median_per_timestep>200
    annual_result = median_result.sum()
    annual_fraction = annual_result/4380
    annual_pct = annual_fraction*100
    ldk_results.append(annual_pct)
ldk_results

[charliebrookerBH]

Adding to this - we also need to be able to visualise the results. I guess to do this we would get the median value for each point...? All these medians are confusing me.

[charliebrookerBH]

Hey @tg359 - please can I get your thoughts on setting up the workflow for this?

BR 209 refers to BS EN 17037 - that defines daylight hours as the 4380 hours with the highest diffuse horizontal illuminance.

Considering this and the varying lux levels required for different rooms, how do you think we should set up this process?

My ideas are:

• Method that takes the results files from an annual daylight analysis (one ill / npy file per grid) and the target lux level, returns a list of % of daylight hours that the target lux has been met/exceeded
• Method that takes a model with grid assigned, an epw, a target lux level, rad_parameters (etc), and returns the returns a list of % of daylight hours that the target lux has been met/exceeded

I'm leaning towards the later approach, essentially where we create a HB Resi CBDM recipe (using HB Annual Daylight as a basis), we could then also create a HB Resi CBDM Metrics component equivalent to HB Annual Daylight Metrics.

At that point we're actually pretty much creating a compliant BS EN 17037 recipe, and it would make more sense to name it so.

[charliebrookerBH]

Looking at the Ladybug Tools github, there's a method for getting daylight hours here:
https://github.com/ladybug-tools/honeybee-radiance/blob/8924b3d781f14253bcd44296246b39ef88182e5c/honeybee_radiance/cli/schedule.py

And reference to the EN17037 post processing here, although the focus of this is on the non-resi and would like need adapting for resi
https://github.com/ladybug-tools/honeybee-radiance/blob/90777a6004b4c75287be472b88b476c66bc59486/honeybee_radiance/postprocess/en17037.py