Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add bioclimatic chart / design suggestions similar to the one in ClimateConsultant #116

Open
stefanoschiavon opened this issue Oct 21, 2021 · 4 comments
Assignees
Labels
enhancement New feature or request

Comments

@stefanoschiavon
Copy link

add bioclimatic and design suggestions similar to the one present in Climate Consultant.

@stefanoschiavon stefanoschiavon added the enhancement New feature or request label Oct 21, 2021
@phuongdoan13 phuongdoan13 self-assigned this Mar 22, 2023
@phuongdoan13
Copy link
Contributor

Hi @stefanoschiavon, for confirmation, is this the chart that you are referring?
image

@FedericoTartarini
Copy link
Contributor

Hi, yes this is the chart that Stefano is referring to. Resolving this issue would be quite complex and require much discussion on how to implement it. Let's try to solve this only if we have a concrete plan on how to move it forward, alternatively let's keep this issue on the side and try to focus on the high-priority issues that are affecting the user's experience or are known bugs. Stefano may add something more.

@giobetti
Copy link
Contributor

giobetti commented Dec 11, 2023

Hello, I've commenced work on this project, aligning it with issue #219 raised by @mccalluc.

The initial step involves incorporating the "comfort zone" into the psychrometric chart, followed by calculating various extensions. To achieve this, I propose integrating the four comfort models from the CBE Thermal Comfort Tool (ASHRAE 55: PMV and adaptive; EN-16798: MV and adaptive) using PyThermal Comfort.

For the layout, I suggest a combination of three graphs, as depicted in the rough Grasshopper mock-up below. Given that the psychrometric chart lacks temporal information, the additional charts, along with standard filters, will address this limitation. Given that it would be impractical to draw a "thermal envelope" for the adaptive methods, coloring the points accordingly is suggested.
PsychrometricsClima_Adaptive

Moving forward, challenges arise when considering expansions, and ingeneral when we claim we can predict indoor conditions based solely on climate data and no real knowldge of the building at hand. The calculation process of climate consultant lacks clear documentation as to how they address this issue.

To calculate the comfort zone, the following inputs are necessary:

  • Outdoor Temperature (adaptive models only)
  • Air temperature (indoor)
  • MRT (in the diagram above, set to be equal to Air Temperature)
  • Air Speed (in the diagram above, set to be equal to zero)
  • Relative humidity (PMV models only)
  • Metabolic rate (PMV models only)
  • Clothing (PMV models only)

I propose experimenting with these parameters to extend the comfort zone:

  • Air Speed: Implement as a slider or drop-down menu, mirroring the CBE Comfort Tool.
  • Thermal Mass: (simple implementation, but open for many comments) Modify MRT, setting it as the running average of Air Temp. This would also enable to relatively easily calculate "low thermal mass buildings" (by setting the period of the running average to a low number i.e. 4 hours) and High thermal mass buildings (by setting the period of the running average to a high number i.e. 24 hours)
  • Thermal mass with Night ventilation: Similar to above, with weighted night-time hours.
  • Internal Gains: Introduce fixed impacts on temperature based on "low," "medium," and "high" internal gains. Suggestions are welcome on how to determine this offset.
  • Solar Gains: Similarly to the internal gains, we could translate irradiation in a proportional increase in indoor air temperatures (and MRT). We could also allow for "low" solar gains and for "high" solar gains. Difficult would be finding a rigorous justification to ground that translation. In practice: 1000Wh/m² correspond to an increase of how many degrees °C in the "low" and the "high" case? This would also need to be orientation dependent(?)
    -Dynamic Solar Shading: This would operate as a condition that would lower the solar gains when they are not increasing the comfortable hours
  • Clothing: there could be an option to define it as as a function of the indoor temperature in the PMV models or as a static value.
  • Metabolic Rate: there could be a couple of preset options

I believe the above list coves most strategies adopted by Climate Consultant with the exception of those based on humidity. Humidity is not a factor in the adaptive comfort models (although evaporative cooling would have an impact on air temperatures).

A couple of considerations:

  1. it seems to me it might make sense to focus on adaptive comfort models rather than PMV models for the "bioclimatic suggestions" as they presuppose limited to no heating and cooling
  2. The challenge lies in calibrating the assumed extensions. Should we run multiple thermal models for calibration? How would we design those thermal models?
  3. A fundamental assumption is indoor temperature equals outdoor temperature. This might be quite misleading.

@FedericoTartarini and @stefanoschiavon (and anyone who made it through here!) your thoughts and comments are highly appreciated.

@stefanoschiavon
Copy link
Author

@giobetti @FedericoTartarini @t-kramer

Here are some ideas related to the proposal of @giobetti

  1. I have always found estimating thermal comfort for the 8760 hours of the year and then plotting on a psychrometric chart or hour-day chat problematic because they often assume constant met and clo, even at night. For the clo, during the day, we could use the dynamic clo model I developed and added to 55. Thermal comfort models are problematic at night because the clothing insulation is hard to estimate. Maybe we should specify that it is mainly for the awake hours. 
  2. ASHRAE 55 and EN are clear that they divide the zone between comfortable and uncomfortable, they do not specify thermal conditions. If we use PMV, then we can plot average thermal sensation using the seven point scale, merging conditions is problematic. For example, pmv=1 is slightly warm, and it cannot be assumed to be hot. So, reducing it to a three-point scale is concerning. 
  3. We need to give some options for airspeed. Even a check box with "Fans available" and a corresponding v=0.8 m/s would be valuable. 
  4. It is ok to assume Tair=MRT following this work.
  5. If we enter the thermal mass/internal gain/solar gains/shading space and perform some simulations, we will make the problem quite big. Following an established method (not sure of current literature, a good person to contact will be Alpha Yacob would be the best idea, even if we just use the ranges in the building bioclimatic chart.
  6. We can relate indoor and outdoor temperatures, assuming simplified models. We develop a very simple linear regression for AC and NV building in this work based on the comfort database II. See Figure 6 in this work.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
enhancement New feature or request
Projects
None yet
Development

No branches or pull requests

4 participants