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Simplifying the HVAC system #15

Closed kamilakrych closed 2 years ago

kamilakrych commented 4 years ago

As discussed with @nheeren and @anistad during our yesterday's call, the HVAC system used in the BuildME archetypes is probably too complex considering the application. It would be nice to simplify it with the use of IdealLoads. I've used such a simplified HVAC system in my thesis (for Brazilian office buildings) so I can try to implement it here as well.

anistad commented 4 years ago

Just to let you know, for the implementation of the office buildings and the new smaller SFH I've used the IdealLoads. Definitely less time consuming!

kamilakrych commented 3 years ago

@shnkn Sahin, you managed to do this! Maybe you can try to explain how you did it, upload the updated files, and we close this issue :blush:

shnkn commented 3 years ago

Thank you @kamilitsa! I have created a branch for it, pushed it to the master (if it is the correct term :)) but I am attaching the final files at the end of the post, just in case. These files are calibrated in a way that they can have a similar final Kwh/m2 value to the previous complex HVAC versions. Cooling and Heating energy consumption are shifted to District Heating and District Cooling Loads since we switched to Ideal Loads (Figure 1).

image Figure 1: Representative Figure of the load shifts between two modeling methods

Ideal Loads without intervening the DHW setup up of the Archetypes

Here I briefly explained the conversion steps I followed in each archetype. The complexity of these models is exponentially increasing from SFH to RT. Especially in the RT archetype, I must admit that I struggled a lot as DHW and HVAC were tangled with each other.

SFH

DHW and HVAC were comparatively modeled separately from each other, so basically there were some objects/inputs to be deleted related to HVAC:

However, some HVAC inputs are sharing some same objects with DHW:

For the Ideal Loads application we need to define three objects in total:

I tried to fill these objects with the values that Andrea and Kamila used in their own studies. I realized that one parameter is very sensitive that is named "Outdoor Flow Rate per Zone Floor Area". The calibration process was mainly adjusting this value to give us similar results as the complex versions.

For SFH this value is found as 0,00023. This value is recalibrated and replaced with 0,00003 For MFH this value is found as 0,00012. This value is recalibrated and replaced with 0,000002 For RT this value is found as 0,00049.

I realized that I made a mistake when I was calibrating the SFH and MFH, I may forget to change the weather file on EP Launch, so I changed the values!

MFH and RT These archetypes have a lot of common objects for HVAC and DHW. In addition, there are a lot of objects to be deleted specifically defined for their HVAC systems. I tried to keep this post short but if this is going to be useful I can document the changes I did similar to the SFH part.

Final Energy Consumption Comparison in comparative trial runs: The trial run models are selected in these settings: 

'USA':
        {'occupation': ['SFH,RT,MFH'],
         'energy standard': ['non-standard'],
         'RES': ['RES0'],
         'climate_region': ['4B'],
         'climate_scenario': ['2015']}}

Accordingly:

(Updated) Archetypes with Ideal Loads and DHW.zip

shnkn commented 3 years ago

I still have some concerns about whether these calibrated values work correctly for different climate zones as well. I am thinking to do some additional comparisons with the archetypes in cold/hot/mild climates. If those values are not working similarly, we might need to define an average value that fits in all cases. Therefore, another calibration process might be required. I hope it is not like that but just for clarification, it would be still good to see the results.

kamilakrych commented 3 years ago

@shnkn Maybe I'm wrong, but I cannot see these changes in the master branch, or in any other branches? Do you still remember how you did this?

nheeren commented 2 years ago

This is done as well I suppose, @kamilitsa ? Can we close it?

kamilakrych commented 2 years ago

Yes, it's done, we can close it. Simplified HVAC system was a pre-requirement for my work with MMV :)