Looking to create a simple passive test cell with NO Mechanical Ventilation

I have posted on this topic before, but responses there are not helping solve this issue:

I am looking to create a simple model with a large shipping container box (12.2m x 2.4m x 2.6m ) to which students will apply different fenestration treatments and natural ventilation options and construction properties. I am adapting the Sample files for this situation. For example:
Test_annual_loads_2.gh (111.2 KB)

(NOTE: the test .gh file has the external shade objects disconnected. The model brep (pink circle) should be linked to a box drawn in Rhino (I use surface extruded) or to the container .3dm file also enclosed.
Container_Large.3dm (159.6 KB)
image

What I am looking for is a way of using the HB Annual Loads component to establish a Passive energy balance, not this, where “mechanical ventilation” is dominant:

Ventilation control for the above looks like this:

The following results from making a change to Vent Control settings:

The settings for this are:

Further along the line for these results I have set the following:
image

It was my expectation that if I set these ventilation settings to zero, then more use would be made of openable windows. But, no.
A quick trial of setting JUST the vent_per_person value to 10l/s/person and disconnecting the vent_ACH and the vent_per_floor inputs produces the following:

I confess that I am not really understanding how to understand these input parameters to manage and explain my demonstration file.

I can ‘explain’ “Mechanical Ventilation” as merely the need to supply minimum fresh air requirements. But the storage terms indicate an error in my inputs, and I am surprised by how slight the natural ventilation cooling energy is.

Any help you can offer would be gratefully received.

Hi @MichaelDonn,

I think I’ve seen this at some point on the forum before. The mechanical ventilation component of the Load Balance for a default Ideal Air system (the default system applied) includes an air side economizer (or an approximation of how one would operate) controlled on Dry Bulb temperature.

So even when you set all the input parameters for ventilation to 0, the free cooling aspect of the mechanical ventilation system still exists by default.

If you plug in your room to the Ideal Air System component you can remove this economizer, which removes the mech vent portion from your loads.

Default Ideal Air System

Ideal Air System with NoEconomizer