How does the example of AFN in LBT1.3 work?

@fn

Unfortunately I don’t have any concrete answers to these questions since it’s a custom workflow that I’ve never tried, but I can make some educated guesses based on what I know. I reccomend doing some experimentation and asking EP-specific questions on UnmetHours to find better answers to your questions.

a further question is, does it mean I can not change the AFN Control type from MultiZoneWithoutDistribution to others like MultiZoneWithDistribution using additional strings if I really want build some ducts and fans into the system?

The current AFN implementation was built specifically for “MultiZoneWithout Distribution” so I don’t know what changes are required to get the AFN to work with “MultiZoneWithDistribution”. Looking at the EP Input Output reference, it looks like the primary changes seems to be adding a AFN:Distribution nodes to corresponding objects in the air loop, and then coupling AFN-defined air ducts to specific zones to get the duct-zone air leakage and conduction loss.
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This doesn’t seem to require changing anything in the natural ventilation objects HB is defining, so it’s possible you can define all this with additional strings and change to the “MultiZoneWithDistribution” condition.

The component in HB-Legacy is not included to LBT yet, and an additional string is needed like @chris said Honeybee Earth Tube component is ready to fly! - #6 by chris
the problem is not solved jet, why can I get the information about the effect of the earth tube in HB Result component.

You can use the “Read Custom Results” component to get any custom outputs for the Earthtube, listed in the Input/Output section for Earthtube (or you can search the “Read Result Dictionary” component for “Earth Tube” outputs.

The Earth Tube belongs also to Airflow Group, so, does it mean I can not use it if the AFN component is applied? and the ZoneCoolTower:Shower, ZoneThermalChimney neither?

Yeah this is confusing. The AFN document seems to only explicitly mention excluding zone mixing, ventilation and infiltration objects, but zone earth tubes and thermal chimney objects are in the same group and behave in the same way: changing the zone heat balance directly based on buoyance-based airflow approximations without actual pressure values.

My best guess is that you can add the “Earth tube” to the AFN network. The AFN models ventilation, infiltration, and zone mixing explicitly, but doesn’t have any objects for earth tubes or thermal chimneys, so my guess is that they exclude only the airflow components the AFN models. I don’t see any reason why the earth tubes/thermal chimney heat transfer couldn’t be incorporated in the zone heat balance while solving for the AFN-driven heat transfer, so I think it should be possible. The only limitation of course is that the earth tube/thermal chimney model wouldn’t be integrated into the AFN-pressure network, and would simply be changing based on the outdoor to zone temperature difference (an approximation of buoyancy). This would be a good question to ask on UnmetHours.