How to study an option with multiple HVAC systems using Group

As you start to layer in more detail into your Sefaira model, you may decide that you want to see the results for your building with more than one HVAC system incorporated.

This is important because it means you can optimise a single HVAC system within a larger building and see how improving the design of the smaller component will have an effect on the performance of the project as a whole.

This can be done very easily in Sefaira using the Group feature.

How the Group feature works

The Group feature enables you to combine two or more iterations (or clones) into a single results set. The results for the Group as a whole are then rolled up and compared to the other iterations in your project. 

Although it can be used other ways, the Group feature is intended to be used in conjunction with the Ignore feature. If you have a single building with two different iterations where alternate parts of the building are ignored, then the remaining pieces in each iteration can be configured to just represent those specific spaces that are left. The models can then be combined into a Group that represents the building as a whole. 

You don't have to have each piece of the building read when you Group them - they can be changed within a Group the same way they can be changed if separate.

Step by step Example - Tower with Fan Coils, Podium with VAV.

Let's say you have a building where the podium is going to be a VAV system with central plant and the tower is going to have fan coil units. A bundle can be set up to support testing each component separately while seeing the impact on the whole building performance.

1) Upload the building form and create a clone of it so that you have 2 iterations.

2) Select the first iteration, name it "tower" and ignore the two floors that will be the podium.



3) Select the second iteration, name it "podium" and ignore all of the floors that comprise the tower.



4) Drag one of the iterations on top of the other to create a Group.

5) Edit the two pieces separately. Apart from changing HVAC systems for each piece you can have completely different properties for materials as well

The Group shows the results for each component of the building in each iteration, plus the results for the combined tower in the Group.

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    Leland Curtis

    Dragging one piece over the other does not create a group. Did something change with the recent update?

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    I am not able to give a VAV system to one floor and Fan coil units to other floors in the way explained above. can u help me?

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    Andrew Corney

    Hi Varshini, I've made a support ticket for you to help.

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    Andrew Corney

    Hi Leland - Sorry I just saw your comment, We had an issue with groups and Internet Explorer for a short while - it has been fixed and should work now. Please submit support tickets for these kinds of issues and we'll get to them faster. Thanks!

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    Marianna Antonina Ciepiela

    Hi Andrew,
    Is it possible to combine two systems on the same floor? For example a VAV for cooling and ventilation with a hydronic system (for example radiators) for heating?